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HardwareHow Filmmaking Cameras WorkMovies don't move. A movie is a series of still pictures presented to the viewer so rapidly that the viewer's brain is fooled into thinking the images are moving. The eye holds the image of one picture for a moment after it is no longer shown until the next picture appears. This is called persistence of vision and allows movies to work. Movies consist of 24 separate still photographs projected each second. This is just fast enough to generally convince the eye that the images are alive and moving. Cameras use a lens to focus the light rays coming from the scene onto a small rectangular area of film or, in the case of video, onto an electronic circuit that is sensitive to light. In a film camera a shutter opens allowing light to shine on the film for a moment, then the shutter closes and the film is advanced to the next frame by a claw mechanism. Then the process repeats 1/24th of a second later. In a video camera light is gather by the electronic circuit for a fraction of a second then the brightness and color values are read out of the circuit for processing and writing to some form of memory. Film formatsFilm consists of light sensitive chemicals coated on a thin, clear cellulose acetate or other flexible plastic film. The chemicals are color dyes and silver compounds (explaining the high cost of photographic film). Most high-budget, professional films are still shot on 35mm color film stock. 35mm film has been the common format since the very first movies. When the film is processed it becomes a negative image of the original scene with the lightest areas of the original scene represented as black on the film, and the darkest areas of the scene staying light and transparent on the film. Colors are also reversed. A positive print has to be made from the negative in order to view the film correctly.
16mm is a lower cost alternative but somewhat lower quality. A few filmmakers experiment with super-8mm but the results don't hold up well in theater projection. All the world's theater projectors are 35mm so any other film size will have to be enlarged and reprinted onto 35mm at some point if it is to be shown in theaters. Film can be shot in a variety of rectangular shapes called aspect ratios. A movie's aspect ratio is given as a ratio of the width of the frame divided by the height. The classic size of 35mm film and standard definition television is a width of 4 units and a height of 3 units giving an aspect ratio of 1.33:1. This aspect ratio is often referred to as Academy aperture after the Academy of Motion Picture Arts and Sciences which first defined and standardized it. Although the Academy frame was standard for most of the early years of filmmaking a wider aspect ratio is now preferred. In America the most common ratio is a 1.85:1 widescreen ratio. Most European films are shot with a 1.66:1 ratio making them not quite as wide as American films project for the same height. The film is shot on the same 35mm film stock but the top and bottom of each frame is cropped by masking it off in the cameras and projectors. High definition video uses an aspect ratio of 16 to 9 units, or 1.78:1 which is very close to 1.85:1 widescreenand makes a transfer to film possible with only a small amount of cropping. Another popular format is anamorphic widescreen having an aspect ratio of 2.35:1. It is sometimes referred to as scope after the trade name Cinemascope. Scope is also shot on the same 35mm stock and the extra wide aspect ratio is achieved by a combination of cropping the top and bottom of the frame and using a special anamorphic lenses which images the scene onto the film by squeezing the image more horizontally than vertically. 35mm cameras are generally very large, heavy and cumbersome pieces of equipment. They require substantial tripods and dollies and several operators to use them. Some newer cameras are small and light enough to be handheld or supported on a Steadicam, a support that is attached to an operator and keeps the camera steady while the operator walks through the scene. 35mm production is worth it when the budget is large enough as non of the current video formats can quite equal the quality. A few productions are even shot using special 65mm or 70mm film and cameras. Films such as Lawrence of Arabia and the popular IMAX films have startlingly rich and detailed images. Film soundMost film cameras do not record sound along with the image. The sound is recorded in a double system where a separate sound recorder captures the sound from the microphones which is later matched to the film during the editing process. For a long time sound was recorded on Nagra analog tape recorders. DAT (digital audiotape) recorders replaced them with their perfect speed and superior sound. Hard disk recorders and even direct to memory card recorders have pretty much taken over professional productions today. These recorders are essentially portable computers dedicated to recording sound. Film cameras designed for making sound films have synchronizing crystal clock circuitry to keep the film moving at a precise speed and in perfect sync with the sound recording. Much of the sound you hear in films today is actually recorded after the fact in a studio. Sound effects, music and even dialog are recorded and added long after the filming is completed. Film editingTraditional film editing is a very mechanical process involving physically cutting and splicing a copy print of the master negative to sequence together the scenes of the movie. Each day's film is processed and printed onto positive film stock and shown to the director as dailies or rushes. Sound is transferred from the original media to 35mm magnetic sound stock to be matched to the image film. When all the sequencing of scenes is done the same cuts are applied to the original master negative in a process called negative matching or conforming. Dissolves between scenes and color correction (called color timing) is done after the editing is finished by optical processes. When the sequencing and color correction is done a sound mix (or rerecording) is done to get the final sound and it is all put together to create an answer print Necessary changes are communicated back to the laboratory from the director and editor. Eventually a release print is produced and the film is ready for distribution and theater screenings. In the 1990s this process began to change as directors chose to capture images from the master negative into digital images in a computer and perform nonlinear editing of the digital images in a computer. When the edit is done the digital images are put back onto film stock for distribution. The process costs more but may make the edit go faster and usually results in a better quality film. Video formatsVideo cameras, like film cameras, focus light to capture a series of still images giving the illusion of motion. They capture light onto a light sensitive computer chip, usually a CCD (charge-coupled device), instead of film. Unlike film which has a relatively continuous light sensitive surface, the computer chips records the scene as a matrix of individual colored spots called pixels. The number of pixels a video camera can capture limits the resolution of the final images. The resulting digital images are usually stored onto magnetic tape, or in some of the latest cameras, onto memory cards. For the purposes of modern filmmaking one can eliminate all the older analog forms of video such as VHS, 8MM and Hi8 because they produce much lower quality images for about the same cost as digital video formats. Standard definition (SD) video, such as mini DV, is not a good choice for making a production intended to viewing in a theater for several reasons. SD video is effectively limited to about 1/4 of a megapixel of resolution, or about 250,000 pixels so the images have poor detail when blown up to the size of a theater screen. The aspect ratio in most cameras is 1.33:1 rather than widescreen. SD also has a frame rate of approximately 30 frames per second rather than 24. To make matters even worse the frames are divided into two interlaced frames every 1/60th of a second. The odd horizontal rows of pixels are made into a picture, then 1/60th of a second later the even horizontal rows of pixels are made into another picture. The two frames can't be combined because any movement in the frame results in two slightly different views so the moving objects seem to have fine comb-like edges. Very clever software is required to convert 30 frame per second interlaced video into single images every 1/24th of a second. High definition (HD) video formats get around many of the issues with SD video. First the resolution is much greater with HD's resolutions of either 1 megapixel per frame or 2 megapixels per frame. Compression techniques reduce this resolution somewhat with many HD recording systems but HD is still startlingly sharper than SD. Many HD cameras can record at 24 frames per second. A few can even record at a variety of frame rates making fast and slow motion filming possible. Some HD cameras also record entire frames at a time, know as progressive filming, eliminating the problem of interlaced images. Video soundUnlike professional film cameras nearly all video cameras have the ability to record muti-track, DAT quality sound onto the same tape as the images, and in perfect sync. This greatly simplifies the production and editing processes of video filmmaking compared to film production. There are three big caveats the beginning filmmaker needs to be aware of. First is that most amateur level video cameras have very low quality sound pre-amplifiers which means that the sound captured is 48khz, 16-bit stereo just like DAT, but will probably have hiss and distortion that would not by added by a professional level video camera. Second is that most amateur level video cameras only offer automatic gain control. This means the camera is constantly trying to adjust the volume of sound capture based on how loud the sound is, resulting in possible distortion due to sudden loud noises and picking up too much background noise when there is little other sound to pick up. Professional production requires being able to set a sound level for capture and keep it constant. Third is that the microphone built into the camera, even the most expensive professional camera, will not get good enough sound for filmmaking. The reason is simply that the built-in microphone will be too far from the actors to register the sound clearly without also picking up an excess of room noise and reverberation. Such poor sound quality is often the most obvious sign of a really amateur production. It doesn't work. You must have a separate, quality microphone that you can get as close as possible to the actors. Video editingVideo editing is easily done on relatively inexpensive personal computers. Digital non-linear editing allows the editor to experiment far beyond what what was ever possible with film editing, and the ability to apply digital enhancements goes far beyond what was possible even a decade ago, at any cost. Digital video editing will be covered more thoroughly in the postproduction section. Film vs. Video, Video vs. FilmNot long ago an independent filmmaker working on a very small budget would shoot 16mm black & white film. The cost savings were significant over 35mm color film. Black & white film is actually more expensive than color film anymore so that isn't an option for saving money. Today the choices of image capture technology are broader than ever but is it really any cheaper to shoot on video rather than film? The quick answer is: No. Equivalent camera packages cost about the same amount to rent whether video or film. You will need the same number of crew members and the same selection of lights, microphones, etc. With film you will pay $50,000 for film and processing up front. With video the tape is cheap but someone has to pay $50,000 to get the film transferred to 35mm film before the movie can be shown in commercial theaters. In the end you've paid the same amount for an equivalent production. Still, there are some important differences. Factors that favor video include:
Factors that favor film include:
The bottom line is that if you really want the look of film and your D.P. wants to shoot on film then find a way to shoot 35mm film. If there is a look you can achieve only with video, portability is a factor, you need to defer as many costs as possible, you are going directly to DVD, you are doing a documentary and must shoot hundred of hours of images or you just have no money but want to make a movie then shoot on video. One is not better than the other. They are just different.
Filmmaking CamerasHDV seems to be the sweet spot for low-budget filmmakers at the moment. There are a handful of "pro" models that are especially interesting. Although they don't all use true HDV technology they all use a form of High Definition recording that will deliver a detailed image the equal of traditional 16mm film or better onto the big screen if properly handled.
For high-end digital filmmaking the choices are:
Mini-DV equipment is available for filmmakers on an even lower budget. You may be able to get a deal purchasing or renting. Top models are:
For 16mm filmmaking some top choices include:
And for 35mm:
Camera tripods and other camera supportsHigh quality tripods and tripod heads are available from:
For filmmaking it is important to use a very stable tripod and fluid head. Fluid heads use a sealed chamber containing oil or other dampening material to give the head a very smooth movement. Filmmaking MicrophonesYour audio workhorse will be your shotgun microphone, boom and mixer. In this illustration the boom operator stands out of the way to the right while he suspends the microphone over the actors trying to get as close as possible without the boom casting a shadow or getting into the camera's field of view.
For outdoor filming a "long shotgun" is preferred. It gives the most directional pickup of sound to get the clearest reproduction of the actor's dialog while reducing the amount of ambience noise picked up. Long shotguns tend to pick up too much echo when used indoors so a short shotgun or cartioid microphone is generally preferred. Top long shotguns good for picking up clear dialog at a distance of 4-5 feet include:
Top short shotguns good for picking up clear dialog at a distance of 2-3 feet include:
The boom pole consists of the boom itself, generally made of fiberglass, a shock mount to isolate the microphone from handling vibration, a wind blimp cover and cable. A lavalier microphone might be used if it isn't practical to use a boom, for example in a long shot where the boom can't get close to the actors without being in the shot. Lavaliers are tiny microphone that can be hidden in the actors clothing or taped to the side of their face away from the camera. Most lavaliers have an omni-directional pickup so must be placed very close to the actor's mouth to get clean sound. They are also very sensitive to picking up wind and clothing noise. Some industry standard lavalier mikes include:
For mixing with popular boom mikes:
Other highly recommended lavaliers include:
Radio, or wireless, transmitter/receivers are used, usually in combinations with lavaliers, when it is not possible to run a wire from the actors to the sound recording device. This can happen when the actors are walking and talking at the same time and a boom can't be used. Radio transmitters are very sensitive to electrical interference and dropouts and are the last choice for picking up sound. Lectrosonic wireless systems are generally considered to be among the best but most of the top microphone manufacturers make high quality wireless transmitters/receivers. Often a matching lavalier microphone is bundled with the wireless transmitter to make a complete solution. Audio MixersAudio mixers balance and control the signal strength of the microphones as the sound is passed on to the recording device. Some recording devices have some ability to control the sound volume built in but it is always better to have a separate mixer that a dedicated sound technician can use. Good mixers include:
Filmmaking LightsCompanies manufacturing lighting equipment of interest to filmmakers include:
Also see the Production page on Lighting for the various techniques involved in film lighting. Movie expendables and general supplies you might want to have on setUse this list as a starting point for your list of expendables to have available at all times.
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| Articles: | Overview | Film Financing | PreProd Buzz | Director's Job |
| Schedule | Locations | Film Crew | Hardware | Casting Actors |
| Auditioning Actors | Rehearsing |