basic equipment n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
BASIC EQUIPMENT PowerPoint Presentation
Download Presentation
BASIC EQUIPMENT

Loading in 2 Seconds...

play fullscreen
1 / 117
ruby-tyler

BASIC EQUIPMENT - PowerPoint PPT Presentation

176 Views
Download Presentation
BASIC EQUIPMENT
An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. BASIC EQUIPMENT ACCT-BVP1-4. Students will be able to demonstrate proper set-up and use of basic production equipment. Demonstrate steps necessary to set-up, turn on, and operate equipment according to instructor’s directions. Load, record, and play video/audio equipment. Demonstrate the use of a computer in broadcast/video production applications. Demonstrate proper picture composition techniques. Demonstrate proper camera movement. Demonstrate proper use of microphones. Identify qualities of a technically acceptable audio track. Demonstrate mastery of aesthetics to include composition, coordination, balance, and color contrast. Demonstrate basic lighting techniques. Explain the care, storage, and use of media hardware and software. Determine proper cables for set-up and operation of production equipment.

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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".

  7. 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 long-term 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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 auto-focus 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: • 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). • 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.

  12. 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 over-used. 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.

  13. 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 auto-focus 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.

  14. 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.

  15. 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 (non-reflective) 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).

  16. 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: • 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. • 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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!

  21. 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 • Don’t pose subjects on backgrounds lighter than they are. • Film a minimum of 5-10 seconds

  22. 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.

  23. Good Quality Video • Head Room- means positioning subjects at a pleasing distance from the top of the picture. Don’t cut off the top of someone’s 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.

  24. 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.

  25. Good Quality Video • Rule of Thirds- If you imagine a tic-tac-toe grid in front of your picture, you can divide the image into thirds instead of halves. The resulting composition will be much more interesting.

  26. 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).

  27. 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.

  28. 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).

  29. 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.

  30. 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.

  31. 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.

  32. 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.

  33. 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.

  34. 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.

  35. 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.

  36. 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 don’t want someone else to record over your footage.

  37. 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.

  38. 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 don’t usually last as long as they are supposed to especially if they are older.

  39. Tripod • Although a skilled camera operator can shoot good quality footage by hand-holding, 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.

  40. 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.

  41. 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.

  42. Hand-Holding the Camera • You can’t always use a tripod, but you should always use a tripod if you can. • If you can’t 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 • Don’t walk while shooting if you can avoid it.

  43. 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 lowest-pitched (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: • Sound Waves: What they are, how they are produced and how we hear them. • 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.

  44. 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 * Radio technician • Live Sound Engineer * Film/Television Sound Recordist • Musician * Audio Editor • Music Producer * Post-Production Audio Creator • DJ * Field Sound Engineer

  45. 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...

  46. 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.

  47. 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. Voilà — 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.

  48. 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.

  49. 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.

  50. 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. • The audio signal from the transducer (microphone) is passed through one or more processing units, which prepare it for recording (or directly for amplification). • The signal is fed to a recording device for storage. • The stored signal is played back and fed to more processors. • The signal is amplified and fed to a loudspeaker.