BASIC EQUIPMENT ACCT-BVP1-4. Students will be able to demonstrate proper set-up and use of basic production equipment. a. Demonstrate steps necessary to set-up, turn on, and operate equipment according to instructors directions. b. Load, record, and play video/audio equipment. c. Demonstrate the use of a computer in broadcast/video production applications. d. Demonstrate proper picture composition techniques. e. Demonstrate proper camera movement. f. Demonstrate proper use of microphones. g. Identify qualities of a technically acceptable audio track. h. Demonstrate mastery of aesthetics to include composition, coordination, balance, and color contrast. i. Demonstrate basic lighting techniques. j. Explain the care, storage, and use of media hardware and software. k. Determine proper cables for set-up and operation of production equipment. Basic Operations of a Video Camera A camcorder is a portable camera/recorder combination. To operate a camcorder successfully, you need to understand four essential controls:
Power Record Zoom White balance: matches the camcorder to the overall color quality of the light in which you are shooting. All camcorders have an automatic setting for white balance. For now, use the automatic setting to let the camcorder read the incoming light color and adjust itself automatically. Always check to make sure your camcorder is set to automatic white balance. Camera Work
These tutorials are designed to provide you with knowledge and skills to improve every aspect of your camera work. They begin at the absolute novice level and work through to professional operations. They are also applicable to any type of camera work. It doesn't matter whether you aspire to be an amateur movie maker or a career camera operator the same basic principles and techniques apply to all. To get the most out of these tutorials, you should have two things: Access to a video camera. You should know how to turn it on, load a tape, press record, etc. If you're having trouble with these basic functions, refer to your camera manual or supplier. Patience. Camera work is a skill which requires lots of learning and practice. Initially it won't really matter what sort of camera you use, but one with a good range of manual functions is preferable. You can get choosy about your camera later.
Although the only equipment you really need is a camera, if you're serious you might want to consider buying a few extra toys. To get started the best accessory you can buy is a good tripod. Terminology It's unavoidable if you're serious, you've got to know some jargon. Fortunately, it's not too complicated. This page contains a few essential terms to get you started. Shot: All video is made up of shots. A shot is basically from when you press record to when you stop recording. Like the individual photos which make up an album, the shots get put together to make a video. Framing & Composition: The frame is the picture you see in the viewfinder (or on a monitor). Composition refers to the layout of everything within a picture frame what the subject is, where it is in the
frame, which way it's facing/looking, the background, the foreground, lighting, etc. When you "frame" a shot, you adjust the camera position and zoom lens until your shot has the desired composition. There is a general set of rules in the video industry which describe how to frame different types of camera shots, such as Wide Shot (WS), Very Wide Shot (VWS), Close Up (CU), etc... Terminology Transition: Shots are linked (edited) in a sequence to tell a larger story. The way in which any two shots are joined together is called the transition. Usually this is a simple cut, in which one shot changes instantly to the next. More complex transitions include mixing, wipes and digital effects. A moving shot (e.g. pan) can also be thought of as a transition from one shot to a new one. The transition is very important in camera work, and you need to think constantly about how every shot will fit in with the ones before and after it. The key is not so much how the transition is achieved technically, but how the composition of each shot fits together.
Here are few more important terms. They will be explained in greater detail later: Pan Side-to-side camera movement Tilt Up-and-down camera movement Zoom In-and-out camera movement (i.e. closer and more distant) Follow: Any sort of shot when you are holding the camera (or have it mounted on your shoulder), and you follow the action whilst walking. Hard to keep steady, but very effective when done well. Iris (Exposure) The opening which lets light into the camera. A wider iris means more light and a brighter picture White balance Adjusting the colors until they look natural and consistent. Shutter Analogous to the shutter in a still camera. Audio Sound which is recorded to go with the pictures.
PLANNING This is the most important step, and perhaps the most difficult to master. It should be where most of your energy is directed. Camera work is only one skill in a larger process the goal of which is usually to produce a completed video, TV program, or presentation of some kind. To be good at camera work, you must have a clear picture of the whole process, and some idea of what the finished product should look & sound like. If there's one thing that separates the amateurs from the pros, it's that amateurs "point and shoot", whereas pros "plan and shoot". Obviously there are times when you don't have time to prepare before having to record sometimes the action begins unexpectedly, and you just have to go for it. In these cases, as far as possible, you plan as you go. It can't be stressed enough planning is everything.
For general camera work, you can divide your plan into two parts: The "Shoot Plan" and the "Shot Plan". SHOOT PLAN In this case, the word shoot refers to a shooting session. If you think of everything you record as being part of a shoot, and have a plan for every shoot, then you're well on the way to having better organized footage. First of all, be clear about the purpose of every shoot. Generally speaking, everything you do should be working towards a larger plan. Exactly what this is will depend on many factors. If you're making a feature film, then the long-term plan is to gather all the shots required by the script/storyboard. If you're making home videos, the long-term plan might be to create a historical archive for future generations (for more suggestions on this topic, see our tutorial on Home Video Production). If you're making a one-off project (such as a wedding video), you still have to bear in mind the longterm implications for the shoot.
Planning means adopting an attitude in which you take control. When you get out your video camera, instead of thinking "This will look good on video" and starting to shoot whatever happens, think "What do I want this to look like on video?". You then shoot (and if necessary, direct) the action to achieve your goal. Plan the approximate length of the shoot: How much footage do you need to end up with, and how long will it take you to get it? Have a checklist of equipment, which could include: camera; tripod; tapes; batteries/power supply; microphones and audio equipment; lights and stands; pens, log sheets and other paper work. PLANNING TO EDIT This is critical. If you think that this doesn't applies to you, then you're wrong. Everything you capture must be shot with editing in mind. There are two basic ways to edit: Post-production and in-camera. Post-production (or just "post") editing means taking the shots you've recorded and re-assembling them later using editing equipment. This is how the professionals work it gives you much greater flexibility when you're shooting and much better finished results. To do simple post editing, all you need is your camera, a VCR, and a few connecting leads. What it means for your shooting plan is that you can collect your shots in any order, and you can get as many shots as you like. At the editing stage, you discard unwanted shots and assemble the good
ones however you like. This can be a time-consuming task (especially if you don't have much editing gear), but it's usually worth the effort. In-Camera editing simply means that what you shoot is what you get there is no post-production. The point here is that you're still editing. You still must decide which shot goes where, and which shots you don't need at all. The difference is that you're making these edit decisions as you shoot, rather than in post. This isn't easy, and it isn't possible to get it right all of the time. It requires planning, foresight, and experience. Note: There is one other situation which should be mentioned: the live multi-camera shoot. This is where a number of cameras are linked to a central vision mixer, and a director cuts between cameras (for example, a live sports presentation). In this case, you can think of the editing as being done in real time as the shoot happens. Whichever method of editing you use, there are fundamental rules to follow. Since understanding these rules requires some knowledge of shot types and framing, we'll leave them for now and come back to them later. SHOT PLAN
Once you have a plan for your shooting session, you're ready to begin planning individual shots. First of all, have a reason for every shot. Ask yourself: "What am I trying to achieve with this shot? Is this shot even necessary? Have I already got a shot that's essentially the same as this one? Is my audience going to care about this subject?" Once you're happy that you have a good reason to get the shot, think about the best way to get it. Consider different angles, framing, etc. The art of good composition takes time to master but with practice you will get there. Ask yourself exactly what information you wish to convey to your audience through this shot, and make sure you capture it in a way that they will understand.
Take the time to get each shot right, especially if it's an important one. If necessary (and if you're editing in post), get a few different versions of the shot so you can choose the best one later. Also, for post editing, leave at least 5 seconds of pictures at the beginning and end of each shot. This is required by editing equipment, and also acts as a safety buffer. Finally, one more piece of advice: Before planning or shooting anything, imagine watching it completed. Camera Settings Many cameras have a menu function with many different functions. On camera editing Date & Time functions Color & Effects
A default setting on a camcorder is an action or condition that is automatically chosen by the equipment, unless you actively select a different one. CAMERA FUNCTIONS Most domestic camcorders can do just about everything automatically. All you have to do is turn them on, point, and press record. In most situations this is fine, but automatic functions have some serious limitations. If you want to improve your camera work, you must learn to take control of your camera. This means using manual functions. In fact, professional cameras have very few automatic functions, and professional camera operators would never normally use autofocus or auto-iris. This is where most beginners ask "Why not? My auto-focus works fine, and my pictures seem to look okay." There are two answers: 1) Although auto-functions usually perform well enough, there will be some situations they
can't cope with (e.g. bad lighting conditions). In these circumstances you may be faced with unusable footage unless you can take manual control. More commonly, your shots will be useable but poor quality (e.g. going in and out of focus). 2) Your camera can't know what you want. To get the best results or obtain a particular effect it is often necessary to over-ride auto-functions and go manual. As you learn more about camera work you will begin to appreciate the better results gained through manual functions. The most common camera operations are briefly explained below (they are covered in more detail in other tutorials). Starting at the beginning, learn and practice one at a time, leaving the others on auto-function. ZOOM This is the function which moves your point of view closer to, or further away from, the subject. The effect is similar to moving the camera closer or
further away. Note that the further you zoom in, the more difficult it is to keep the picture steady. In some cases you can move the camera closer to the subject and then zoom out so you have basically the same framing. For long zooms you should use a tripod. Zooming is the function everyone loves. It's easy and you can do lots with it, which is why it's so overused. The most common advice we give on using the zoom is use it less. It works well in moderation but too much zooming is tiring for the audience. FOCUS Focus is the state of an image when the lines of contrast appear as sharp as possible: in focus. Auto-focus is a common feature on consumer cameras that keeps only the center of the picture in focus. It is strictly for amateurs. Unlike still photography, there is no way autofocus can meet the needs of a serious video camera operator. Many people find manual focus difficult, but if you want to be any good at all, good focus control is essential. Professional cameras usually have a manual focus ring at the front of the lens housing. Turn the ring clockwise for
closer focus, counter-clockwise for more distant focus. Consumer cameras have different types of focus mechanisms usually a small dial. To obtain the best focus, zoom in as close as you can on the subject you wish to focus on, adjust the ring until the focus is sharp, then zoom out to the required framing. IRIS This is an adjustable opening (aperture), which controls the amount of light coming through the lens (i.e. the "exposure"). As you open the iris, more light comes in and the picture appears brighter. Professional cameras have an iris ring on the lens housing, which you turn clockwise to close and counter clockwise to open. Consumer-level cameras usually use either a dial or a set of buttons. The rule of thumb for iris control is: Set your exposure for the subject. Other parts of the picture can be too bright or darks, as long as the subject is easy to see.
WHITE BALANCE White balance means color balance. It's a function which tells the camera what each color should look like, by giving it a "true white" reference. If the camera knows what white looks like, then it will know what all other colors look like. This function is normally done automatically by consumer-level cameras without the operator even being aware of it's existence. It actually works very well in most situations, but there will be some conditions that the auto-white won't like. In these situations the colors will seem wrong or unnatural. To perform a white balance, point the camera at something matt (nonreflective) white in the same light as the subject, and frame it so that most or all of the picture is white. Set your focus and exposure, then press the "white balance" button (or throw the switch). There should be some
indicator in the viewfinder which tells you when the white balance has completed. If it doesn't work, try adjusting the iris, changing filters, or finding something else white to balance on. You should do white balances regularly, especially when lighting conditions change (e.g. moving between indoors and outdoors). AUDIO Virtually all consumer-level cameras come with built-in microphones, usually hi-fi stereo. These work fine, and are all you need for most general work. Getting better results with audio is actually quite difficult and is a whole subject in itself. We won't go into it much here you just need to be aware that audio is very important and shouldn't be overlooked. If you're keen, try plugging an external microphone into the "mic input" socket of your camera (if it has one). There are two reasons why you might want to do this: 1. You may have a mic which is more suited to the type of work you are doing than the camera's built-in mic. Often, the better mic will simply be mounted on top of the camera.
2. You might need to have the mic in a different position to the camera. For example, when covering a speech, the camera could be at the back of the room with a long audio lead running to the stage, where you have a mic mounted on the pedestal. The level at which your audio is recorded is important. Most cameras have an "auto-gain control", which adjusts the audio level automatically. Consumer-level cameras are usually set up like this, and it works well in most situations. If you have a manual audio level control, it's a good idea to learn how to use it (more on this later). Gain is the strength of an audio or video signal. AUDIO If possible, try to keep the background (ambient) noise level more or less consistent. This adds smoothness to the flow of the production. Of course, some shots will require sudden changes in ambient audio for effect. Listen to what people are saying and build it into the video. Try not to start and finish shots while someone is talking there's nothing worse than a video full of half-sentences. Be very wary of background music while shooting this can result is music that jumps every time the shot changes, like listening to a badly
scratched record. If you can, turn the music right down or off. One more thing... be careful of wind noise. Even the slightest breeze can ruin your audio. Many cameras have a "low-cut filter", sometimes referred to as a "wind-noise filter" or something similar. These do help, but a better solution is to block the wind. You can use a purpose-designed wind sock, or try making one yourself. SHUTTER At the beginner level you don't really need to use the shutter, but it deserves a quick mention. It has various applications, most notably for sports or fast-action footage. The main advantage is that individual frames appear sharper (critical for slow-motion replays). The main disadvantage is that motion appears more jerky. The shutter can also be used to help control exposure. EFFECTS Many consumer cameras come with a selection of built-in digital effects, such as digital still, mix, strobe, etc. These can
be very cool, or they can be very clumsy and tacky. They require dedicated experimentation to get right. Like so many things in video, moderation is the key: use them if you have a good reason to, but don't overdo it. You should also be aware that almost every effect you can create with a camera can be done better with editing software. If at all possible, shoot your footage "dry" (without effects) and add effects later. Any in camera effects you use will permanently be saved to your video and you will not be able to take them off later, so make sure you really want them on your film. If you are not sure that you want a specific effect wait until you can test it using the editing software. REMEMBER Although it is sometimes the more practical solution to use automatic features, as a general rule you should do as many camera operations manually as you can AS YOU BECOME MORE ADVANCED & COMFORTABLE WITH THE EQUIPMENT. ALWAYS START OFF USING THE
AUTOMATIC FEATURES ESPESCIALLY IN THIS CLASS! Avoiding Camera Problems Do not move from place to place with the camera mounted on the tripod. Avoid Quick movements and zooms in and out Dont pose subjects on backgrounds lighter than they are. Film a minimum of 5-10 seconds FRAMING Shots are all about composition. Rather than pointing the camera at the subject, you need to compose an image. As mentioned previously, framing is the process of creating composition. Notes: Framing technique is very subjective. What one person finds dramatic, another may find pointless. What we're looking at here are a few accepted industry guidelines which you should use as rules of thumb.
The rules of framing video images are essentially the same as those for still photography. Good Quality Video Head Room- means positioning subjects at a pleasing distance from the top of the picture. Dont cut off the top of someones head. Look Room Center your subject in the center from left to right only if they are looking at you. If your subject is looking to the left or right, leave more room in the direction in which they are looking. Lead Room- Allow extra room in front of the subject as they are moving left or right. Good Quality Video Rule of Thirds- People tend to center subjects in their picture. A tree is photographed dividing the frame vertically. The horizon is placed so it divides the image horizontally. The resulting picture
looks balanced and rather dull. You might call this kind of composition the rule of halves because the frame is divided in half on both sides. Good Quality Video Rule of Thirds- If you imagine a tic-tactoe grid in front of your picture, you can divide the image into thirds instead of halves. The resulting composition will be much more interesting. Good Quality Video An axis is the same in video as in graphed algebra equations. The X axis is horizontal (left-to-right) and the Y axis is vertical (top-to-bottom). Good Quality Video Everything in your frame is important, not just the subject. What does the background look like? What's the lighting like? Is there anything in the frame which is going to be
distracting, or disrupt the continuity of the video? Pay attention to the edges of your frame. Avoid having half objects in frame, especially people (showing half of someone's face is very unflattering). Also try not to cut people of at the joints the bottom of the frame can cut across a person's stomach, but not their knees. It just doesn't look right. Once you're comfortable with the do's and don'ts, you can become more creative. Think about the best way to convey the meaning of the shot. If it's a baby crawling, get down on the floor and see it from a baby's point-of-view (POV). If it's a football game, maybe you need to get up high to see all the action. Look for interesting and unusual shots. Most of your shots will probably be quite "straight"; that is, normal shots from approximate adult eye-level. Try mixing in a few variations. Different angles and different camera positions can make all the difference. For example; a shot can become much more dramatic if shot from a low point. On the other hand, a new and interesting perspective can be obtained by looking straight down on the scene. Be aware that looking up at a person can make them appear more imposing, whereas looking down at a person can diminish them.
Watch TV and movies, and notice the shots which stand out. There's a reason why they stand out it's all about camera positioning and frame composition. Experiment all the time. SHOOTING TECHNIQUE Position yourself and your camera. If you're using a tripod, make sure it's stable and level (unless you have a reason for it to be tilted). If the tripod has a spirit level, check it. If you're going to be panning and/or tilting, make sure that you'll be comfortably positioned throughout the whole move. You don't want to start a pan, then realize you can't reach around far enough to get the end of it. If it's going to be difficult, you're better off finding the position which is most comfortable at the end of the move, so that you start in the more awkward position and become more comfortable as you complete the move. If the tripod head doesn't have a bowl (this includes most cheaper tripods), it's very important to check that the framing still looks level as you pan - it may be okay in one direction but become horribly slanted as you pan left
and right. If you're not using a tripod, stabilize yourself and your camera as best you can. Keep your arms and elbows close to your body (you can use your arms as "braces" against your torso). Breathe steadily. For static shots, place your feet at shoulder width (if you're standing), or try bracing yourself against some solid object (furniture, walls, or anything). SHOOTING TECHNIQUE Frame your shot. Then do a quick mental check: white balance; focus; iris; framing (vertical and horizontal lines, background, etc.). Think about your audio. Audio is just as important as vision, so don't forget about it. Press "record". Once you're recording, make sure that you are actually recording. There's no worse frustration than realizing that you were accidentally recording all the time you were setting the shot up, then stopped recording when you thought you were starting.
Many cameras have a tape "roll-in time", which means that there is a delay between the time you press record and when the camera begins recording. Do some tests and find out what your camera's roll-in time is, so you can then compensate for it. SHOOTING TECHNIQUE Many cameras have a tape "roll-in time", which means that there is a delay between the time you press record and when the camera begins recording. Do some tests and find out what your camera's roll-in time is, so you can then compensate for it. Keep checking the status displays in the viewfinder. Learn what all the indicators mean they can give you valuable information. Use both eyes. A valuable skill is the ability to use one eye to look through the viewfinder, and the other eye to watch your surroundings. It takes a while to get used to it, but it means that you can walk around while shooting without tripping over, as well as keeping an eye out for where the action is happening. It's also easier on your eyes during long shoots. SHOOTING TECHNIQUE
Learn to walk backwards. Have someone place their hand in the middle of your back and guide you. These shots can look great. You'll often see television presenters walking and talking, as the camera operator walks backwards shooting them. Keep thinking "Framing...Audio..." As long as you're recording, think about how the frame composition is changing, and what's happening to the sound. Press "record stop" before moving. Just as in still photography, you should wait until one second after you've finished recording (or taken the photo) before you move. Too many home videos end every shot with a jerky movement as the operator hits the stop button. SHOOTING TECHNIQUE Use the "date/time stamp" feature sparingly. It's unnecessary to have the time and date displayed throughout your video, and it looks cheap. If you must have it there, bring it up for a few seconds, then get rid of it. Modern digital cameras have the ability to show or hide this
display at any time after recording. Be prepared to experiment. Think about some of the things you'd like to try doing, then try them at a time that doesn't matter (i.e. don't experiment while shooting a wedding). Most new techniques take practice and experimentation to achieve success, and good camera work requires experience. If you want to be good, you'll have to invest some time. SHOOTING TECHNIQUE Use the "date/time stamp" feature sparingly. It's unnecessary to have the time and date displayed throughout your video, and it looks cheap. If you must have it there, bring it up for a few seconds, then get rid of it. Modern digital cameras have the ability to show or hide this display at any time after recording. Be prepared to experiment. Think about some of the things you'd like to try doing, then try them at a time that doesn't matter (i.e. don't experiment while shooting a wedding). Most new techniques take practice and experimentation to achieve success, and good camera work requires experience. If you want to be good, you'll have to invest some time.
Videotape Types: VHS, VHS-C, 8mm, MiniDV, DVD, Hard drive Be careful inserting the video tape! Miniaturized camcorders are somewhat delicate. You can break them by forcing a tape. If the tape does not slide in easily, make sure it is facing the correct direction. Preparing the tape Once the tape is inside the camcorder, it must be prepared for use. If the tape is brand ne, roll it forward about 30 seconds. Do this by pressing the record button with the cap still covering the lens. This is done because the first few inches of tape will gradually stretch as the cassette is repeatedly rewound to its beginning, eventually ruining any material recorded there. Preparing the tape
If you have used a tape before, you must prepare it by rolling down to raw stock. Tape Preparation is very important because you never know who filmed before you and where they left the tape. You do not want to accidentally record over someone else's or your own footage and you dont want someone else to record over your footage. Batteries Camcorders may be used with an A/C power adapter or a battery. If you are around a power outlet, use it and conserve your batteries for when you are not around a power outlet. Batteries are not indestructible and can be damaged by dropping them or leaving them in extreme temperatures. Batteries Camcorders may be used with an A/C power
adapter or a battery. If you are around a power outlet, use it and conserve your batteries for when you are not around a power outlet. Batteries are not indestructible and can be damaged by dropping them or leaving them in extreme temperatures. Never go out shooting without at least one fully charged battery. Batteries usually dont usually last as long as they are supposed to especially if they are older. Tripod Although a skilled camera operator can shoot good quality footage by handholding, it is difficult to obtain steady images without the support of a tripod. Shaky pictures are the most obvious signs of amateurish production. Your hands are not as steady as you think they are. Because many students smoke and drinking high level caffeine drinks their hands shake more than they should and it is more evident on film.
Tripod There are two major parts to a tripod, the tripod itself and the tripod boot. The tripod boot screws into the bottom of the camera. Make sure you do not screw it in too tightly, or you may crack the bottom of the camera. In order to insert the tripod boot into the camera, make sure to move the quick release mechanism so that the boot fits in easily and then move the quick release again to secure. Using the Tripod Make sure the tripod head is level by adjusting the lengths of the legs or using the ball head. If the tripod has a center column, try not to use it, because it makes the tripod less stable. Point one leg at the subject to be video taped. Doing this will let you stand close behind the camera, in the space between the other two
legs. When you pan the camera (pivot it from side to side), stand facing the center of the move. To make the shot, twist your upper body to frame the start of the shot, the opposite way until you frame the end of the shot. Hand-Holding the Camera You cant always use a tripod, but you should always use a tripod if you can. If you cant use a tripod, never use the flip out screen. Instead, use the eye piece and both hands. This helps to steady your shot. Prop yourself up Hold your breath Dont walk while shooting if you can avoid it. INTRODUCTION TO AUDIO What is "Audio"?
Audio means "of sound" or "of the reproduction of sound". Specifically, it refers to the range of frequencies detectable by the human ear approximately 20Hz to 20kHz. It's not a bad idea to memorize those numbers 20Hz is the lowestpitched (bassiest) sound we can hear, 20kHz is the highest pitch we can hear. Audio work involves the production, recording, manipulation and reproduction of sound waves. To understand audio you must have a grasp of two things: 1. Sound Waves: What they are, how they are produced and how we hear them. 2. Sound Equipment: What the different components are, what they do, how to choose the correct equipment and use it properly. Fortunately it's not particularly difficult. Audio theory is simpler than video theory and once you understand the basic path from the sound source through the sound equipment to the ear, it all starts to make sense. Technical note: In physics, sound is a form of energy known as acoustical
energy. INTRODUCTION TO AUDIO The Field of Audio Work The field of audio is vast, with many areas of specialty. Hobbyists use audio for all sorts of things, and audio professionals can be found in a huge range of vocations. Some common areas of audio work include: Studio Sound Engineer Live Sound Engineer Musician Music Producer DJ *
* * * * Radio technician Film/Television Sound Recordist Audio Editor Post-Production Audio Creator Field Sound Engineer INTRODUCTION TO AUDIO In addition, many other professions require a level of audio proficiency. For example, video camera operators should know enough about audio to be able to record good quality sound with their pictures. Speaking of video-making, it's important to recognize the importance of audio in film and video. A common mistake amongst amateurs is to
concentrate only on the vision and assume that as long as the microphone is working the audio will be fine. However, satisfactory audio requires skill and effort. Sound is critical to the flow of the program indeed in many situations high quality sound is more important than high quality video. Most jobs in audio production require some sort of specialist skill set, whether it be micing up a drum kit or creating synthetic sound effects. Before you get too carried away with learning specific tasks, you should make sure you have a general grounding in the principles of sound. Once you have done this homework you will be well placed to begin specializing. The first thing to tackle is basic sound wave theory... INTRODUCTION TO AUDIO
Sound waves can also be shown in a standard x vs y graph, as shown here. This allows us to visualize and work with waves from a mathematical point of view. The resulting curves are known as the "waveform" (i.e. the form of the wave.) The wave shown here represents a constant tone at a set frequency. You will have heard this noise being used as a test or identification signal. This "test tone" creates a nice smooth wave which is ideal for technical purposes. Other sounds create far more erratic waves. Click here to listen to this tone (22KB wav file) Note that a waveform graph is two-dimensional but in the real world sound waves are three-dimensional. The graph indicates a wave traveling along a path from left to right, but real sound waves travel in an expanding sphere from the source. However the 2-dimensional model works fairly well when thinking about
how sound travels from one place to another. INTRODUCTION TO AUDIO The next thing to consider is what the graph represents; that is, what it means when the wave hits a high or low point. The following explanation is a simplified way of looking at how sound waves work and how they are represented as a waveform. Don't take it too literally treat it as a useful way to visualize what's going on. In an electronic signal, high values represent high positive voltage. When this signal is converted to a sound wave, you can think of high values as representing areas of increased air pressure. When the waveform hits a high point, this corresponds to molecules of air being packed together densely. When the wave hits a low point the air molecules are spread more thinly. In the diagram below, the black dots represent air molecules. As the loudspeaker vibrates, it causes the surrounding molecules to vibrate in a particular pattern represented by the
waveform. The vibrating air then causes the listener's eardrum to vibrate in the same pattern. Voil Sound! Note that air molecules do not actually travel from the loudspeaker to the ear (that would be wind). Each individual molecule only moves a small distance as it vibrates, but it causes the adjacent molecules to vibrate in a rippling effect all the way to the ear. Now here's the thing: All audio work is about manipulating sound waves. The end result of your work is this series of high and low pressure zones. That's why it's so important to understand how they work - they are the "material" of your art. INTRODUCTION TO AUDIO How Sound Waves Interact with Each Other When different waves collide (e.g. sound from different sources) they interfere with each other. This is called, unsurprisingly, wave interference.
Phasing The following table illustrates how sound waves (or any other waves) interfere with each other depending on their phase relationship: Sound waves which are exactly in phase add together to produce a stronger wave. Sound waves which are exactly inverted, or 180 degrees out of phase, cancel each other out and produce silence. This is how many noise-cancellation devices work. Sound waves which have varying phase relationships produce differing sound effects. INTRODUCTION TO AUDIO Sound Systems
Working with audio means working with sound systems. Naturally, the range of systems available for different applications is enormous. However, all electronic audio systems are based around one very simple concept: To take sound waves, convert them into an electric current and manipulate them as desired, then convert them back into sound waves. A very simple sound system is shown in the diagram below. It is made up of two types of component: Transducer - A device which converts energy from one form into another. The two types of transducers we will deal with are microphones (which convert acoustical energy into electrical energy) and speakers (which convert electrical energy into acoustical energy). Amplifier - A device which takes a signal and increases it's power (i.e. it increases the amplitude).
The process begins with a sound source (such as a human voice), which creates waves of sound (acoustical energy). These waves are detected by a transducer (microphone), which converts them to electrical energy. The electrical signal from the microphone is very weak, and must be fed to an amplifier before anything serious can be done with it. The loudspeaker converts the electrical signal back into sound waves, which are heard by human ears. INTRODUCTION TO AUDIO
The next diagram shows a slightly more elaborate system, which includes: Signal processors - devices and software which allow the manipulation of the signal in various ways. The most common processors are tonal adjusters such as bass and treble controls. Record and playback section - devices which convert a signal to a storage format for later reproduction. Recorders are available in many different forms, including magnetic tape, optical CD, computer hard drive, etc. 1. The audio signal from the transducer (microphone) is passed through one or more processing units, which prepare it for recording (or directly for amplification). 2. The signal is fed to a recording device for storage. 3. The stored signal is played back and fed to more processors.
4. The signal is amplified and fed to a loudspeaker. INTRODUCTION TO AUDIO The 3-part audio model One simple way of visualizing any audio system is by dividing it up into three sections: the source(s), processor(s) and output(s). The source is where the electronic audio signal is generated. This could be a "live" source such as a microphone or electric musical instrument, or a "playback" source such as a tape deck, CD, etc. The processing section is where the signal is manipulated. For our purposes, we will include the amplifiers in this section. The output section is where the signal is converted into sound waves (by loudspeakers), so that it can be heard by humans. This portable stereo is a good example of a simple system.
INTRODUCTION TO AUDIO Sources: There are three sources - two tape machines and one radio aerial (technically the radio source is actually at the radio station). Processors: Includes a graphic equalizer, left/right stereo balance, and amplifiers. Outputs: There are two speaker cabinets (one at each end), each containing two speakers. Note that there are also two alternative outputs: A headphone socket (which drives the small speakers inside a headphone set) and twin "line out" sockets (which supply a feed for an external audio system). Now imagine a multi-kilowatt sound system used for stadium concerts. Although
this is a complex system, at it's heart are the same three sections: Sources (microphones, instruments, etc), processors and speakers. Whatever the scale of the project, the same underlying principles of sound reproduction apply. CONNECTIONS This section explains the different types of audio cable and connectors. Audio Cables There are two main types of audio cable we will look at: Single core / shielded (unbalanced) and One pair / shielded (balanced). Single Core / Shielded Cable In a single core / shielded cable, the single core is used for the +ve, or 'hot', and the shield is used for the -ve, or 'cold'. This type of cable is used for unbalanced audio signals.
Single core / shielded cable One Pair / Shielded Cable A one pair / shielded cable has one core as the +ve, and the other core is ve. The shield is earthed. This type of cable is used for balanced audio signals. One pair / shielded cable AUDIO CONNECTORS There are a variety of different audio connectors available. The most common types are 3-pin XLR, RCA, and 6.5mm jacks (also known as " jacks). 3-pin XLR 3-pin XLR connectors are mainly used for balanced audio signals. Using a
balanced signal reduces the risk of inference. Pin 1 is the earth (or shield) Pin 2 is the +ve (or 'hot') Pin 3 is the -ve (or 'cold). There are a number of different XLR's - 3-pin, 4-pin, 5-pin etc 3-pin XLR Male 3-pin XLR Female AUDIO CONNECTORS " Jack (6.5mm Jack)
There are two types of 6.5mm Jacks: Mono and stereo. The mono jack has a tip and a sleeve, the stereo jack has ring, a tip and a sleeve. On the mono jack the tip is the +ve, and the sleeve is the -ve or shield. On a stereo jack being used for a balanced signal, the tip is the +ve, the ring is the -ve, and the sleeve is the shield. On a stereo jack being used for a stereo signal (left and right), the tip is the left, the ring is the right, and the sleeve is the shield. Jacks also come in various sizes - 6.5mm ("), 3.5mm, 2.5mm. The wiring for all of them is the same. 1/4" Mono Jack 1/4" Stereo Jack RCA
AUDIO CONNECTORS RCAs are used a lot for home stereos, videos, DVDs etc. The RCA can carry either audio or video. It is wired the same way as a mono jack: The center pin is the +ve, and the outer ring is the -ve or shield. RCA Male HOW TO USE MICROPHONES This section aims to provide you with the skills to choose the correct microphone and use it properly to obtain the best possible sound. It is suitable for people interested in any type of audio or video work. The microphone (mic) is a ubiquitous piece of equipment. Found in everything from telephones to computers to recording studios, microphones are part of our daily life. Few people think about the microphone in their telephone when they use it. Some
people think about the microphone on their video camera when they use it. All professionals pay careful attention to their microphones whenever they use them. Don't make the mistake that many amateurs make and use whatever mic is at hand (e.g. using a vocal mic for a bass drum). Also, don't make the mistake of assuming that using a microphone is easy. Microphone technique is a learned skill - plugging it in and pointing it isn't always enough. The microphone is perhaps the most critical part of the audio chain (assuming that all other components are at least acceptable quality). A good quality microphone will provide you with the basis for excellent audio, whereas a poor quality microphone will mean poor quality audio - no matter how good the rest of the system is. HOW TO USE MICROPHONES Choosing the Right Microphone As we discussed in the previous section, there are many different types of microphone in common use. The differences are usually described in two ways: The technology they use (e.g. dynamic, condenser, etc) and their directionality (e.g. omnidirectional, cardioid, etc). In addition, microphones have a number of other characteristics which need to be
taken into account. When choosing a microphone, the first thing you will need to know is what characteristics you need. After that, you can worry about things like size, brand, cost, etc HOW TO USE MICROPHONES Things to Consider Work through each of these characteristics and determine your needs. Directionality Decide which type of directional pattern best fits your needs. Remember that it's usually better to use a less directional mic in a position close to the sound source, than to be further away using a hypercardioid. For more information see microphone directional characteristics.
Frequency Response Make sure the mic's frequency response is appropriate for the intended use. As a rule of thumb flat response patterns are best, but in many cases a tailored response will be even better. For more information see microphone frequency response. Impedance The rule of thumb is: Low impedance is better than high impedance. For more information see microphone impedance. HOW TO USE MICROPHONES Handling Noise Remember that the diaphragm works by converting vibrations from sound waves into an electrical signal. Unless the microphone has some sort of protection system, the diaphragm can't tell the difference between a desirable sound wave vibration and any other sort of vibration (such as a person tapping
the microphone casing). Any sort of vibration at all will become part of the generated audio signal. If your mic is likely to be subjected to any sort of handling noise or vibration, you will need a mic which will help prevent this noise from being picked up. High quality hand-held mics usually attempt to isolate the diaphragm from vibrations using foam padding, suspension, or some other method. Low quality mics tend to transfer vibrations from the casing right into the diaphragm, resulting in a terrible noise. Note that lavaliere mics don't usually have protection from handling noise, simply because they are too small to incorporate any padding. It is therefore important to make sure they won't be moved or bumped. HOW TO USE MICROPHONES Purchasing a Microphone
If you can afford it, it makes sense to buy a range of microphones and use the most appropriate one for each job. If your budget is more limited, think about all the different things you need to use the mic for and try to find something which will do a reasonable job of as many of them as possible. For vocalists a simple cardioid dynamic mic (such as the Sure SM58) is a good starting point. For video makers, a useful option is a condenser mic with selectable directionality, so you can change between cardioid and hypercardioid. If you can afford three mics, consider a hand-held dynamic, a shotgun condenser, and a lapel mic. HOW TO USE MICROPHONES Comparisons In the end, sound is quite subjective. You really want a mic which will provide the sound you like. A good idea is to set up a controlled test. Record the same sounds using different mics, keeping all other factors constant.
Make sure you are comparing apples with apples; for example, don't compare a hand-held cardioid and a shotgun in the same position. If you do want to compare these mics, make sure each is placed in its optimum position. HOW TO POSITION A MICROPHONE Distance The golden rule of microphone placement is get the distance right. In general, place the microphone as close as practical to the sound source without getting so close that you introduce unwanted effects (see below). The aim is to achieve a good balance between the subject sound and the ambient noise. In most cases you want the subject sound to be the clear focus, filled out with a moderate or low level of ambient noise. The desired balance will vary depending on the situation and the required effect. For example, interviews usually work best with very low ambient noise. However if you want to point out to your audience that the surroundings are very noisy
you could hold the mic slightly further away from the subject. It is possible to get too close. Some examples: If a vocal mic is to close to the speaker's mouth, the audio may be unnaturally bassy (boomy, excessive low frequencies). You are also likely to experience popping and other unpleasant noises. A microphone too close to a very loud sound source is likely to cause distortion. Placing a mic too close to moving parts or other obstacles may be dangerous. For example, be careful when micing drums that the drummer isn't going to hit the mic. HOW TO POSITION A MICROPHONE Phase Problems When using more than one microphone you need to be wary of phasing, or cancellation. Due to the way sound waves interfere with each other, problems can occur when the same sound source is picked up from different mics placed at slightly different distances. A common
example is an interview situation in which two people each have a hand-held mic - when one person talks they are picked up by both mics and the resulting interference creates a phasing effect. HOW TO POSITION A MICROPHONE Think Laterally You don't always have to conform to standard ways of doing things. As long as you're not placing a microphone in danger there's no reason not to use them in unusual positions. For example, lavaliere mics can be very versatile due to their small size - they can be placed in positions which would be unrealistic for larger mics. Examples Guitar amps are miced very closely. This helps keep the sound isolated from the rest of the stage noise. Theoretically the amp will not create any level burst strong enough to distort the microphone.
Snare drum mics need to be close to the skin without getting in the way of the drummer or risking damage. MICROPHONE STANDS, MOUNTS & CLAMPS An important consideration is the way the microphone is held or mounted. A poorly mounted mic can lead to all sorts of problems, whereas a well-mounted mic can lift the audio quality significantly. Things to consider when mounting a mic include: The mic obviously needs to be correctly positioned, facing the required direction. You should be able to reposition the mic if necessary. The mic must be safe, i.e. Won't fall over, get knocked, get wet, etc.
The mic must be shielded from unwanted noise such as handling noise, vibrations, wind, etc. Cables must be secure and safe. In particular, make sure no one can trip over them. There are many ways to mount microphones. Let's look at the most common methods... MICROPHONE STANDS, MOUNTS & CLAMPS Microphone Stands The most obvious mount is the microphone stand. There are three main variations: The straight vertical stand, the boom stand and the small table-top stand. Boom stands are very useful and versatile. If you are considering buying a general-purpose stand, a boom stand is the logical choice.
Some things to watch out for when setting up a microphone stand: Always position the boom to extend directly above one of the stand legs. This prevents the stand from tipping over. Don't wrap the lead a hundred times around the stand. This serves no purpose except make your life difficult and possibly increase twisting pressure on the lead. One turn around the vertical part of the stand and another turn around the boom is all you need. Never stand on the legs. You will wreck them. Never over-tighten clamps. Do them up until they are firm - no more.
Don't try to adjust clamps while they are tightened - undo them first. Note: Boom arms are controlled by sound operators. Boom Stand Tabletop Stand MICROPHONE STANDS, MOUNTS & CLAMPS Clamps Instead of using a dedicated mic stand, you can use a specialized clamp to piggyback on another stand (or any other object). Advantages:
Disadvantages: Less floor space is used, more mics can be squeezed into the same area. Less equipment to carry (clamps are smaller and lighter than stands). Can sometimes be useful reaching difficult positions. Can sometimes be tricky to set up and more difficult to get exactly the right positioning. Also more difficult to move or adjust once set up. More likelihood of unwanted vibration noise creeping into the mix. Clamps are often used in musical situations where there are many stands and many microphones. The classic example is the drum kit which is surrounded by cymbal stands - clamps are well suited to this application.
MICROPHONE STANDS, MOUNTS & CLAMPS Clothing Clip Lavaliere (lapel or lap) mics are usually attached to the subject's clothing using a specialized clip. Obviously the preferred position is on the lapel or thereabouts. This provides consistent close-range sound pickup and is ideal for interview situations in which each participant has their own mic. It also means the subject doesn't have to worry about mic technique. If you have time, discreetly hide the cable in the clothing. If there is nowhere to place the mic on the subject's chest, try the collar. MICROPHONE STANDS, MOUNTS & CLAMPS Headset
A headset with its own mic works well in situations such as: When the person talking needs to listen as well as speak. When the person talking must be able to move around with their hands free. When there is a lot of background noise, likely to be distracting the subject. Headsets are ideal for stage performers, as well as sports commentators, radio announcers, etc. Like lav mics, they provide very consistent audio. Shock Absorption
In order to minimize unwanted noise caused by vibration of the stand or mount, a shock absorption system may be used. This isolates the mic from the vibrations, usually with foam padding or elastic suspension. MICROPHONE STANDS, MOUNTS & CLAMPS Boom Microphone The boom microphone is very popular in film and television production. A directional mic is mounted on a boom arm and positioned just out of camera frame, as shown on the right. The cable is wrapped once or twice around the boom arm. Booms have the advantage of freeing up subjects from having to worry about microphones. They can move freely without disturbing the sound, and concerns about microphone technique are eliminated. You can make a simple boom from just about anything which is the right shape. A microphone stand with its legs removed is a good option, or even a broomstick or fishing pole. MICROPHONE STANDS, MOUNTS & CLAMPS
A good boom will have some sort of isolating mechanism for the microphone to prevent vibrations being transferred to the mic. This may involve elastic suspensions, foam padding, etc. The distance between the microphone and subject must be carefully controlled. The mic must be as close as possible without any chance of getting in frame (you might want to allow a safety margin in case the framing changes unexpectedly). It must also maintain a reasonably consistent distance to avoid fluctuating audio levels. Make sure the boom doesn't cast a show on the scene. In the example on the right, the sound operator is also acting as a guide for the camera operator as they walk backwards, keeping a constant distance from the walking subjects. MICROPHONE STANDS, MOUNTS & CLAMPS Hand-held Microphones The term "hand-mic" generally means any microphone held in the hand and used to pick up human speech. Hand-mics are used in a huge variety of settings, from musical performances to television interviews. When you say "microphone", most people picture a hand-mic. Everyone knows what they are and what they do, and
everyone thinks they know how to use them. Sadly, this is not the case. Although there is a knack to using the hand-mic properly, it's really not difficult to learn. Perhaps that's why it's so frustrating to see people get it wrong - because it's so easy to get it right. MICROPHONE STANDS, MOUNTS & CLAMPS Listed below are some general rules of microphone technique. We've used the example of a television presenter conducting an interview, but these rules can be applied to most situations. Be aware of what type of mic you're using. In particular, you should know about it's directional characteristics. Make sure you do a sound check yourself, well before the interview. Position yourself and the microphone, and speak exactly as you intent to during the interview. If the mic has an on/off switch, keep an eye on it. If the mic is battery-powered, make sure you turn it off when you've finished. Hold the microphone firmly. Remember that the mic will pick up any handling noise so be careful not to move your hand around on the mic casing, or bump the mic into anything. If you're exposed to the wind, try and give the mic some shelter.
MICROPHONE STANDS, MOUNTS & CLAMPS Hold the mic at a constant distance and angle from your mouth (or your subject's mouth). Around 15-20cm from the mouth should be fine. Any more than this, and not only will the voice become weak, but other noises will become more prominent. Any closer than this, and you'll get various unpleasant sound effects (such as "popping"). (Note that musicians have a special set of rules for mic distance. Most vocalists hold their mics fairly close to their mouths.) Always direct the mic towards the person who's talking. You can also use micpointing to direct your subjects. When you point it at yourself, you're talking. When you point it at the subject, you're saying "Now it's your turn to talk". If you have more than one subject, you can use the mic to point toward the person you want to speak. Never give the mic away during an interview. It's not uncommon for a subject to want to hold the mic, but don't let them. It creates all sort of problems and it's just not worth it. MICROPHONE STANDS, MOUNTS & CLAMPS Looking After Your Microphones Obey the normal common-sense rules of electronic equipment care, e.g. avoid very high temperatures, dust, dampness, high humidity, physical shocks, etc.
Many performers think it's cool to swing the mic by its lead and generally throw it around the place. Unless you own the mic and you can afford to replace it regularly, don't do this. Don't blow into the mic. The diaphragm is designed to respond to sound waves, not wind. Don't tap the head of the microphone. This can damage the mic and/or speakers. If applicable, turn mics off when not in use. Remove and replace batteries regularly. The action of removing and inserting batteries can help keep the contacts clean. Don't subject microphones to volume levels greater than their design capabilities. Always be careful with phantom power. Although it will not generally harm your microphone, it's prudent to play it safe. Keep all leads safely secured. If someone trips over a lead there may be all sorts of problems from damaged mics to lawsuits. If the performance of a mic deteriorates over time, it may be possible to have the diaphragm cleaned. You will need to talk to the supplier or manufacturer for details. Good Quality Audio Stay close to the subject regardless of the type of camera and/or microphone you use, the closer you keep the camera and/or microphone to your subject, the better your audio will be.
Good Quality Audio Minimize Background Noise You should always scout where you plan on filming. Some places are simply too noisy to get good audio. Some places may have background noises such as air conditioners, open doors leading to noisy rooms, etc Always point your camera and microphone away from background noise. Good Quality Audio Direct Silently Do not give verbal instructions from the camera position wile shooting. Camcorder mikes pick up sounds to the sides as well as in front. You can ruin sound takes because your own voice is mixed with production sound. There is a reason that 2 and 1 are silent when you are counting in a take. 5,4,3, silent 2, 1, and point to start a take. The
camera man should have started filming on or before 5. SOUND QUALITY How to Prevent Distortion Unwanted distortion is caused by a signal which is "too strong". If an audio signal level is too high for a particular component to cope with, then parts of the signal will be lost. This results in the rasping distorted sound. An example of this would be turning your television or radio up to loud, making it sound like you are about to blow your speakers. SOUND QUALITY Minimizing Distortion Distortion can occur at almost any point in the audio pathway, from the microphone to the speaker. The first priority is to find out exactly where the problem is. Ideally, you would want to measure the signal level at as many points as possible, using a VU (Volume Unit) meter or
similar device. Generally speaking, you should keep the level below about 0dBu at every point in the pathway. SOUND QUALITY If you can't measure the signal level, you'll have to do some deducing. Follow the entire audio pathway, beginning at the source (the source could be a microphone, tape deck, musical instrument, etc). Here are some things to look for: Is the distortion coming from a microphone? This could be caused by a very loud noise being too close to the mic. Try moving the mic further away from the noise source. Are you seeing any "peak" or "clip" lights on any of your equipment? These are warnings that a signal level is too high.
Are any volume or gain controls in your system turned up suspiciously high? Are there any obvious points where you could drop the level? Are your speakers being driven too hard? If you have an amplifier which is pushing the speakers beyond their design limits, then be careful - you may well find that the distortion becomes permanent. If the distortion is coming from occasional peaking, consider adding a compressor. Could the distortion be caused by faulty equipment? Is the problem really distortion? There are some other unpleasant noises which could be confused with distortion; for example, the graunching
sounds made by a dodgy cable connection or dirty volume knob. SOUND QUALITY How to Eliminate Feedback Audio feedback is the ringing noise (often described as squealing, screeching, etc) sometimes present in sound systems. It is caused by a "looped signal", that is, a signal which travels in a continuous loop. In technical terms, feedback occurs when the gain in the signal loop reaches "unity" (0dB gain). One of the most common feedback situations is shown in the diagram below a microphone feeds a signal into a sound system, which then amplifies and outputs the signal from a speaker, which is picked up again by the microphone. Of course, there are many situations which result in feedback. For example, the microphone could be replaced by the pickups of an electric guitar. (In fact many guitarists employ controlled feedback to artistic advantage. This is what's happening when you see a guitarist hold his/her guitar up close to a speaker.) SOUND QUALITY
To eliminate feedback, you must interrupt the feedback loop. Here are a few suggestions for controlling feedback: Change the position of the microphone and/or speaker so that the speaker output isn't feeding directly into the mic. Keep speakers further forward (i.e. closer to the audience) than microphones. Use a more directional microphone. Speak (or sing) close to the microphone. Turn the microphone off when not in use. Equalize the signal, lowering the frequencies which are causing the
feedback. Use a noise gate (automatically shuts off a signal when it gets below a certain threshold) or filter. Lower the speaker output, so the mic doesn't pick it up. Avoid aiming speakers directly at reflective surfaces such as walls. Use direct injection feeds instead of microphones for musical instruments. Use headset or in-ear monitors instead of speaker monitors. You could also try a digital feedback eliminator. There are various models available with varying levels of effectiveness. The better ones are reported to produce reasonable results. SOUND QUALITY Other Notes: Feedback can occur at any frequency. The frequencies which cause most trouble will depend on the situation but factors include the room's resonant frequencies, frequency response of microphones, characteristics of musical instruments (e.g. resonant frequencies of an acoustic guitar), etc.
Feedback can be "almost there", or intermittent. For example, you might turn down the level of a microphone to stop the continuous feedback, but when someone talks into it you might still notice a faint ringing or unpleasant tone to the voice. In this case, the feedback is still a problem and further action must be taken. SOUND QUALITY Audio Equalization Equalization, or EQ for short, means boosting or reducing (attenuating) the levels of different frequencies in a signal. The most basic type of equalization familiar to most people is the treble/bass control on home audio equipment. The treble control adjusts high frequencies, the bass control adjusts low frequencies. This is adequate for very rudimentary
adjustments it only provides two controls for the entire frequency spectrum, so each control adjusts a fairly wide range of frequencies. Advanced equalization systems provide a fine level of frequency control. The key is to be able to adjust a narrower range of frequencies without affecting neighboring frequencies. Equalization is most commonly used to correct signals which sound unnatural. For example, if a sound was recorded in a room which accentuates high frequencies, an equalizer can reduce those frequencies to a more normal level. Equalization can also be used for applications such as making sounds more intelligible and reducing feedback. There are several common types of equalization. SOUND QUALITY
Shelving EQ In shelving equalization, all frequencies above or below a certain point are boosted or attenuated the same amount. This creates a "shelf" in the frequency spectrum. Bell EQ Bell equalization boosts or attenuates a range of frequencies centered around a certain point. The specified point is affected the most, frequencies further from the point are affected less. Graphic EQ Graphic equalizers provide a very intuitive way to work separate slider controls for different frequencies are laid out in a way which represents the frequency spectrum. Each slider adjusts one frequency band so the more sliders you have, the more control.
Parametric EQ Parametric equalizers use bell equalization, usually with knobs for different frequencies, but have the significant advantage of being able to select which frequency is being adjusted. Parametric are found on sound mixing consoles and some amplifier units (guitar amps, small PA amps, etc). SOUND QUALITY Audio Monitoring & Metering Audio Metering means using a visual display to monitor audio levels. This helps maintain audio signals at their optimum level and minimize degradation. There are two common types of meter which are used to measure audio levels: VU Meter (Volume Unit) PPM Meter (Peak Program) VU Meter SOUND QUALITY
A VU (volume unit) meter is an audio metering device. It is designed to visually measure the "loudness" of an audio signal. The VU meter was developed in the late 1930s to help standardize transmissions over telephone lines. It went on to become a standard metering tool throughout the audio industry. VU meters measure average sound levels and are designed to represent the way human ears perceive volume. The rise time of a VU meter (the time it takes to register the level of a sound) and the fall time (the time it takes to return to a lower reading) are both 300 milliseconds.
The optimum audio level for a VU meter is generally around 0VU, often referred to as "0dB". Technically speaking, 0VU is equal to +4 dBm, or 1.228 volts RMS across a 600 ohm load. VU meters work well with continuous sounds but poorly with fast transient sounds. SOUND QUALITY Peak Program Meter (PPM) A Peak Program Monitor (PPM), sometimes referred to as a Peak Reading Meter (PRM), is an audio metering device. It's general function is similar to a VU meter but there are some important differences.
The rise time of a PPM (the time it takes to register the level of a sound) is much faster than a VU meter, typically 10 milliseconds compared to 300 milliseconds. This makes transient peaks easier to measure. The fall time of a PPM (the time it takes the meter to return to a lower reading) is much slower. PPM meters are very good for reading fast, transient sounds. This is especially useful in situations where pops and distortion are a problem. SOUND QUALITY Both types of meter are available in various forms including stand-alone units, components in larger systems, and software applications. Whatever the type of meter,
two characteristics are important: The scale which defines which units are being measured. The ballistics of the meter which determine how fast it responds to sound and returns to a lower level. SOUND QUALITY Audio Processing Audio Processing means changing the characteristics of an audio signal in some way. Processing can be used to enhance audio, fix problems, separate sources, create new sounds, as well as to compress, store and transmit data. The following tutorials cover some common types of audio processing:
Compression : Reducing the dynamic range of a signal. Expansion : Expanding the dynamic range of a signal. Equalization : Increasing or decreasing the levels of different frequencies in a signal. Limiting : Constraining the level of a signal to a specified threshold. Reverb : Adding reverberation to a signal. Phasing : Creating interesting effects through sound wave phase interaction. Flanging : A specific type of phasing. Chorus : An effect which makes a single source sound like multiple sources. SOUND QUALITY Audio Effects This section provides an overview of the most common audio effects used in sound production, with links to more
detailed tutorials. Equalization Equalization means boosting or reducing (attenuating) the levels of various frequencies in a signal. At it's most basic, equalization can mean turning the bass/treble controls up or down. Advanced equalizers have fine controls for specific frequencies. Common uses for equalization include correct signals which sound unnatural and reducing feedback. SOUND QUALITY Compression & Limiting Compression means reducing the dynamic range of a signal. All signal values above a certain adjustable threshold are reduced in gain relative to lower-level signals. This creates a more even signal level, reducing the level of the loudest parts. Limiting is an extreme form of compression. Rather than smoothly reducing the gain of successively higher levels, all signal above the threshold is limited to the same gain. This creates a very hard cut-off point, over which there is no increase in
level. SOUND QUALITY Expansion & Noise Gating Expansion means increasing the dynamic range of a signal. High level signals maintain the same (or nearly the same) levels, low level signals are reduced (attenuated). This creates a greater range between quiet and loud. Expansion is the opposite of compression. Noise gating is an extreme form of expansion signals below a certain point are either heavily attenuated or eliminated completely. This leaves only higher level signals and removes background noise when the signal is not present. Delay / Echo Delay is a simple concept the original audio signal is followed closely by a
delayed repeat, just like an echo. The delay time can be as short as a few milliseconds or as long as several seconds. A delay effect can include a single echo or multiple echoes, usually reducing quickly in relative level. Delay also forms the basis of other effects such as reverb, chorus, phasing and flanging. Reverb Reverb is short for reverberation, the effect of many sound reflections occurring in a very short space of time. The familiar sound of clapping in an empty hall is a good example of reverb. Reverb effects are used to restore the natural ambience to a sound, or to give it SOUND QUALITY Chorus
The chorus effect is designed to make a signal sound like it was produced by multiple similar sources. For example, if you add the chorus effect to a solo singer's voice, the results sounds like.... a chorus. Chorus works by adding multiple short delays to the signal, but rather than repeating the same delay, each delay is "variable length" (the speed and length of the delay changes). This adds the randomness required for the chorus sound. Varying the delay time also varies the pitch slightly, further adding to the "multiple sources" illusion. Phasing & Flanging Phasing, AKA phase shifting, is a sweeping, whooshing effect often used in music. The effect is created by mixing the original signal with another version of
itself which has been phase-shifted. This results in various out-of-phase interactions over time which gives the sweeping effect. Phasing is created by adding evenly-spaced notches in the frequency response and moving them up and down the frequency spectrum. Flanging is a specific type of phasing which uses notches that are "harmonically LIGHTING TERMINOLOGY Common Lighting Terminology Ambient Light - The light already present in a scene, before any additional lighting is added. Incident Light - Light seen directly from a light source (lamp, sun, etc).
Reflected Light - Light seen after having bounced off a surface. Color Temperature - A standard of measuring the characteristics of light, measured in kelvins. Contrast Ratio - The difference in brightness between the brightest white and the darkest black within an image. Key Light - The main light on the subject, providing most of the illumination and contrast.
Fill Light - A light placed to the side of the subject to fill out shadows and balance the key light. Back Light - A light placed at the rear of a subject to light from behind. LIGHTING TERMINOLOGY Hard Light - Light directly from a source such as the sun, traveling undisturbed onto the subject being lit. Soft Light - Light which appears to "wrap around" the subject to some degree. Produces less shadows or softer shadows. Spot - A controlled, narrowly-focused beam of light.
Flood - A broad beam of light, less directional and intense than a spot. Tungsten - Light from an ordinary light bulb containing a thin coiled tungsten wire that becomes incandescent (emits light) when an electric current is passed along it. Tungsten color temperature is around 2800K to 3400K. Also known as incandescent light. Halogen - Type of lamp in which a tungsten filament is sealed in a clear capsule filled with a halogen gas. Fresnel - A light which has a lens with raised circular ridges on its outer surface. The fresnel lens is used to focus the light beam.
Incandescent - Incandescent lamps produce heat by heating a wire filament until it glows. The glow is caused by the filament's resistance to the current and is called incandescence. TYPES OF LIGHTS These are some common types of light you'll often hear about in film, video and photography. Note that these definitions are not always rigid and some people may interpret them a little differently. Blonde - 1000-2000w, used as a key flood light for large areas. Redhead - 650-1000w, used as a key flood light for large areas. Pepper Light - 100-1000w, small light used as a more focused key or fill light.
HMI - A high-quality type of light which uses an arc lamp instead of filament bulb. Halogen Work Lamp - 150-500w, used as a key flood light for lighting large areas. This is a low-budget lighting solution. Other Lights - Domestic light bulbs can be used at a pinch, ideally as a secondary light such as fill or backlight. Many video cameras have built-in lights or the ability to mount a light these are useful in emergencies but provide poor quality lighting. Chinese Lanterns - A low-cost light, useful in some situations. Instruments / Housing Fresnel - A light which has a lens with raised circular ridges on its outer surface which are used to focus the light beam. LIGHTING EQUIPMENT
Some common types of equipment used in video and photography lighting. 18% Gray Card - A gray-colored card which reflects 18% of the light which falls upon it. Used as a reference to calibrate light meters and set exposure. Ballast - A device used to control the electrical current in a light. Consoles - Hardware and software systems which control lighting. Operated by the lighting technician, consoles coordinate lighting displays on stages, studios, etc. Light Meter - A tool used to measure light and indicate the ideal exposure setting. Also known as an exposure meter.
Reflector Board - A specially-designed reflective surface used to act as a secondary light source. The board is lightweight and flexible, and is normally folded up for transport in a small carry-case. Gels - Materials which are placed in front of a light source to alter it's characteristics, e.g. color temperature or dispersion (see diffusion gels). Spectrometer - A professional-level instrument which measures the spectrum of light. Technically speaking, a spectrometer analyses the electromagnetic spectrum and measures the intensity of radiation as a function of wavelength. Stands & Clamps - Systems used to support lights and hold them in the correct position. COLOR TEMPERATURE
Color Temperature Chart Color temperature is a standard method of describing colors for use in a range of situations and with different equipment. Color temperatures are normally expressed in units called kelvins (K). Note that the term degrees kelvin is often used but is not technically correct (see below). COLOR TEMPERATURE Technically speaking... Color temperature means the temperature of an ideal black body radiator at which the color of the light source and the black body are identical. (A black body is a theoretical radiator and absorber of energy at all electromagnetic wavelengths.) Color Temperature in Video For video operations the relevant temperatures range from around 2,000K to 8,000K these are common lighting conditions. In practical terms this usually means selecting lights, gels and filters which are most appropriate to the prevailing light or to create a particular color effect. For example, a camera operator will select a "5600K filter" to
use outside in the middle of a sunny day. COLOR TEMPERATURE Terminology When referring to the unit kelvin, it is not capitalized unless it is the first word of a sentence. The plural is kelvins (e.g. "The light source is approximately 3200 kelvins"). The symbol is a capital K (e.g. "The light source is approximately 3200K"). When referring to the Kelvin scale, it is capitalized (e.g. "The Kelvin scale is named after William Thomson (1824 1907), also known as Lord Kelvin". Degrees kelvin
According to The International System of Units (SI) , color temperatures are stated in kelvins, not in degrees Kelvin. The "degrees" part of the name was made obsolete in 1967. However, the "degrees" reference has remained in common use in media industries. LIGHTING Contrast Ratio Contrast Ratio is a measurement of the difference in brightness between the whitest white and the darkest black within an image. A ratio of 300:1 means the brightest point in the image is 300 times as bright as the darkest point. A higher contrast ratio therefore means a larger difference in brightness. Contrast ratio is of interest in two situations: 1. Cameras: When recording an image (video, film, photography) 2. TVs, Monitors, etc. When choosing or setting up a playback device
(TV, computer monitor, etc) LIGHTING The Standard 3-Point Lighting Technique The Three Point Lighting Technique is a standard method used in visual media such as video, film, still photography and computer-generated imagery. It is a simple but versatile system which forms the basis of most lighting. Once you understand three point lighting you are well on the way to understanding all lighting. The technique uses three lights called the key light, fill light and back light. Naturally you will need three lights to utilize the technique fully, but the principles are still important even if you only use one or two lights. As a rule: If you only have one light, it becomes the key. If you have 2 lights, one is the key and the other is either the fill or the backlight. Key Light LIGHTING This is the main light. It is usually the strongest and has the most influence on the look of the scene. It is placed to one side of the camera/subject so that this
side is well lit and the other side has some shadow. Fill Light This is the secondary light and is placed on the opposite side of the key light. It is used to fill the shadows created by the key. The fill will usually be softer and less bright than the key. To achieve this, you could move the light further away or use some spun. You might also want to set the fill light to more of a flood than the key. LIGHTING Back Light The back light is placed behind the subject and lights it from the rear. Rather than providing direct lighting (like the key and fill), its purpose is to provide definition and subtle highlights around the subject's outlines. This helps separate the subject from the background and provide a three-dimensional look.
If you have a fourth light, you could use it to light the background of the entire scene. Manage the Shooting Session Designate one person to take responsibility for the camcorder and tripod at all times. That person is never to leave the immediate area of the equipment. If you are hand-holding the camcorder, never set it down on anything except its tripod. It is easy to grab a camera from a table or a sidewalk and run. It is much harder and more conspicuous to snatch both camera and tripod. Also, the tripod makes the camera more visible, so it is less likely to be bumped or knocked to the ground. Manage the Shooting Session Detach the camcorder from the tripod when transporting them. If the camcorder has a handle, never use it to lift both camera and
tripod together. The handle is not strong enough to carry the weight of both pieces. Always protect the camcorder from the weather. Keep it out of hot sun except when actually shooting. Do not allow it to get wet, particularly the delicate glass of the zoom lens. Plastic bags can be used to cover your camera if you are caught off guard in the rain, just poke a hole in the bag to get a clear shot. Manage the Shooting Session Do not ask people to perform feats for the camera that they would not normally attempt. Professional stunt people are highly trained, very experienced, and well paid for taking risks. Your cast and crew are not. Do not put the crew at risk, (say, by hanging out over balconies or climbing on high roofs) in pursuit of interesting camera angles.
Manage the Shooting Session Remember that the videographer is concentrating intently on the viewfinder, it is easy for that person to run into objects or stumble on stairs. An assistant should guide the videographer during moving shots. Get permission and be courteous when shooting in public so that you are not ban from filming in certain areas. You should not film anyone if you do not have written permission to use their image. Manage the Shooting Session Be smart, you are using a video camera that captures video and sound. Do not do or say anything that you would not be comfortable with your parents or an administrator seeing or hearing. You must tell your teacher where you are going before you leave the classroom to
film. You must be where you said you would be in case your teacher or the front office needs to find you. You may only be out of the classroom for 20 minutes at a time. STUDY QUESTIONS Directions: On your own paper WRITE the following questions and their answers. 1. How does the appearance of an image change when the gain is adjusted? 2. What challenges are presented when hand-held shooting with a video camera? 3. List the benefits of using a tripod when shooting outside of the studio. 4. How does the rule of thirds affect picture composition? 5. What is head room? 6. How does the camera angle affect the audiences perception of a character? 7. Explain how a microphone works
8. List five types of microphones available and the unique characteristics of each. 9. How does feedback occur? 10. How can feedback be prevented? STUDY QUESTIONS Directions: On your own paper WRITE the following questions and their answers. 11. What is the difference between male and female connector ends? 12. Which connectors are likely to be found on home entertainment equipment? 13. What Items can be used to redirect or change the shape of light? 14. How do different frequencies (colors) of light affect a recorded video image? 15. List each of the instruments used in three-point lighting and explain the function of each. 16. What are three different common camera movements? Describe each. 17. What should you not do to a microphone? 18. What qualifies as a technically acceptable audio track?
19. What are the basic functions of a video camera? 20. When using video equipment, when should you use Automatic functions? VOCABULARY/TERMINOLOGY Directions: On your own paper WRITE the Terms and their definitions. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Auto-Focus Camcorder Focus Gain
Shot Framing Composition Transition Pan Tilt 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. Zoom Follow White Balance Audio
Key Light Fill Light Back Light Color Temperature Spot Light Flood Light PROJECT MY LIFE VIDEO MONTAGE A montage is a production device that allows a gradual change in a relationship or a lengthy time passage to occur in a very short amount of screen time by showing a series of silent shots accompanied by music. Create a montage that chronicles your life up until this year. You should include the following: Pictures of yourself for each year of your life (or as close as you can get) Pictures of your family Pictures of your pets (if you have one) Pictures of your friends Pictures of yourself playing sports, having fun, recreational shots, etc Video of yourself introducing you, sections of your montage, and/or closing out your montage. (you will film this in class, no exceptions) Music (that is appropriate for school)
Title screens/overlays Your montage should be between 2 & 3 minutes It is easier to add pictures to your montage if you bring them in on a disc or some other storage device. However, we do have scanners if you need to scan in some pictures.