Cinematography-Theory-And-Practice

Figure 16.3. (top) A large bluescreensetup lit with Kino Flo units. (Photocourtesy of Kino Flo.)Figure 16.4. (middle) Typical bluescreen(or greenscreen) lightingsetup with Kino Flos. (Photo courtesyof Kino Flo.)Figure 16.5. (bottom) Spacing isimportant for even illumination ofthe cyc, which is critical for a goodprocess shot. (Photo courtesy ofKino Flo.)When shooting greenscreen/bluescreen:guard against backsplash, 12 to 15 feet if possible. variation on any part of the screen is ideal.shooting greenscreen, don’t have green props or anybody wearinggreen wardrobe. incident meter to read the subject.used for film. This is based on differences in how film and videoreact to colors with the least amount of noise.The reason you use an incident meter to read the subject and a spotmeter (reflectance meter) for the background is that greenscreen/bluescreen materials vary in their reflectivity. We are not concernedwith how much light is hitting the background, only how muchlight it is reflecting back toward the camera. For the subjects (actorsor whatever) being photographed, we read them as we normallywould, with an incident meter. Using a spot meter on an actor canbe tricky. What part of them do you read? Their forehead? Theirshirt? Their hair? With a reflectance meter those are all likely to bedifferent readings. Which one of them represents the actual exposure,the f/stop the lens should be set at? Yes, you can do it, if youhave a good understanding of the Zone system, as discussed in thechapter Exposure. It is possible, but not usually necessary; an incidentmeter gives us an excellent reading when used properly as previouslydiscussed: holding the meter so that it is receiving the same lightingas the subject, receptor aimed at the camera, and a hand shielding themeter from backlight, kickers or any other stray light that might notbe relevant to the subject exposure.When shooting video, a waveform monitor is useful in judgingexposure and balance; a vectorscope can reveal any color problems.Luminance KeyLuminance key is the same concept as chroma key except that the differencebetween light and dark objects is used as the key for producinga difference matte. If the subject is primarily light colored,then the background and all parts of the scene that you want tobecome transparent so that the composited background plate willshow through should be black. The opposite is true if the subject ispredominantly dark and shadowy.DIMMERSThere are a number of ways we control the intensity of a light’soutput at the unit itself:soft lights)The alternative is to control the power input into the light withdimmers. There are advantages and disadvantages.cinematography314