Cinematography-Theory-And-Practice

Figure 12.21. This shot from FightClub is typical of a scene lit with ordinaryfluorescent bulbs uncorrected.Table 12.3. MinusGreen and Plus-Green are gels that are used to correctfor the green spike in fluorescentlights. MinusGreen (which ismagenta) is used to subtract thegreen, while PlusGreen is used toadd green to your lights so that theymatch the green of existing fluorescentsor industrial sources at thelocation. Values are expressed in CC(color correction) units, which is howa color meter measures tint — thegreen/magenta axis of color.ReduceGreenCCEquivilentUse When CCIs ApproxMinusGreen 30 -121/2 MinusGreen 15 -51/4 MinusGreen 0.75 -2Add GreenCCEquivilentUse When CCIs ApproxPlusGreen 30 +131/2 PlusGreen 15 +51/4 PlusGreen 0.75 +3a room, the windows will be the wrong color (too blue) and muchtoo bright. The purpose of this is to avoid having to put two separategels on a window, which might increase the possibility for gel noiseand reflections, not to mention the additional cost (which can besubstantial). There are two reasons lighting gels cost as much as theydo: first, they are carefully calibrated in their color, and also they areincredibly resistant to heat, which is important as they are frequentlyjust inches or a foot or two away from a blazing hot light source.They are made from polyester, high-temperature polymer, polycarbonate,or dichroic filters, which are thin optical coatings on glass.CTO is used not only for color correction but also to warm uplight; so warming a scene with full CTO, half CTO, or quarterCTO is a common practice. There are other warming gels as well,and every DP has preferences as to how to approach making the lighton a scene warmer. Some use dimmers on tungsten lights; dimmingthese lights down, makes them shift toward red/orange. With video/HD it is possible to make the entire scene warmed by “fooling” thewhite balance” (see chapter on HD Cinematography).With film and video there are a wide variety of lens filters and lightinggels that can warm or cool a shot. Gel manufacturers provide awide range of both warming and cooling gels that allow for greatever,that both of these methods change the color of the entire scene.Putting gels on lights or windows allows you to be selective withtrade-off: clearly it is faster and cheaper to use a filter or change thewhite balance of a camera; gelling lights or windows takes time andmoney, but it offers far more control of the image.CTBFilters for converting warm tungsten sources to nominal daylightare called full blue, Tough Blue or CTB (Color Temperature Blue). The36%, while 85 has a transmission of 58%. This means that while youbalance tungsten lights inside a room with the daylight blue windowlight that is coming in. The window light is liable to be far morecinematography240