Cinematography-Theory-And-Practice

cumulative effect that we might expect. For example, combining a#8 and #15 filter gives the same visual effect as a #15 filter alone(although the filter factor is changed by the combination of the two).there is usually a single filter which will do the same job.PolarizersNatural light vibrates in all directions around its path of travel. Apolarizer transmits the light that is vibrating in one direction only.Polarizers serve a variety of functions. Glare on a polished surface or-Brewster’s angle, 56° from normal, or 34° from the surface, is theWhen working with glare on water and on windows it is seldomdesirable to eliminate all reflections because this creates an unnatu-works well for static shots, but care must be taken if a pan or tiltcamera moves in relation to the sky. If the sky is overcast, the polar-allyat least 1 2/3 to 2 stops as a filter factor, which does not changechange as you pan or tilt the camera.Beam Splitter Viewfinders and PolarizersWhen using cameras with video assist and modern beam splitters, circular pola filters.The term circular refers to technology used to make them, notfilters aren’t used, there will be problems with either image in thefinder or on the video assist. The image on the film is not affected.The reason for this is that modern beam splitters use a dielectric coat-not be used together, there will be problems. The circular pola filterhas a front and back and the orientation is important. The front mustpoint towards the subject or it won’t be effective.Some camera viewfinders exhibit a magenta appearance with ordinarypola filters. On other cameras, the video goes very dark. Thisdoes not happen with circular polas.Density FiltersNeutral density filters are used to reduce overall exposure withoutaffecting color rendition. They can be used in extremely high-illuminationsituations (such as a sunlit snow scene or a beach scene)where the exposure would be too great or where reduced exposureis desired to crush depth of field. Neutral density filters combinedwith 85 correction filters (85N3, 85N6, and 85N9) are a standardorder with any camera package for exterior work. You may want tobring a set of neutral density filters on an HD shoot as well.Also known as Wratten #96, the opacity of ND filters is given indensity units so that .3 equals one stop, .6 equals two stops, and .9equals three stops. In gelatin filters, ND’s are available in .1 increments(1/3 of a stop). If you combine ND filters, the density valuesare added.TABLE 11.4 COLOR CORRECTION (CC)FILTERS FOR THE CAMERA LENSCC.025Y -CC05Y -CC10Y 1/3YELLOW CC20Y 1/3(Absorbs Blue) CC30Y 1/3CC40Y 1/3CC50Y 2/3CC.025M -CC05M 1/3CC10M 1/3MAGENTA CC20M 1/3(Red-blue) CC30M 2/3CC40M 2/3CC50M 2/3CC.025 C -CC05C 1/3CC10C 1/3CYAN CC20C 1/3(Blue-green) CC30C 2/3CC40C 2/3CC50C 1CC.025R -CC05R 1/3CC10R 1/3RED CC20R 1/3CC30R 2/3CC40R 2/3CC50R 1CC.025G -CC05G 1/3CC10G 1/3GREEN CC20G 1/3(Absorbs Blue and Red) CC30G 2/3CC40G 2/3CC50G 1CC.025B -CC05B 1/3CC10B 1/3BLUE CC20B 2/3(Absorbs Green and Red) CC30B 2/3CC40B 1TABLE 11. 3 WRATTEN FILTERS CC50B (81 & 82) 1 1/3Filter #Exp.FactorMiredTo Get3200KFrom:82C + 82C 1 1/3 -89 2490K82C + 82B 1 1/3 -77 2570K82C+82A 1 -65 2650KCOOLING 82C+82 1 -55 2720K82C 2/3 -45 2800K82B 2/3 -32 2900K82A 1/3 -21 3000K82 1/3 -10 3100K81 1/3 +9 3300K81A 1/3 +18 3400KWARMING TABLE 11.281BTHE 1/3 80 SERIES +27 3500K81C 1/3 +35 3600K81D 2/3 +42 3700K81EF 2/3 +52 3850KFILTER CONVERSION EXP. LOSS80A 3200 > 5500 -131 2 stops80B 3400 > 5500 -112 1 2/3 stops80C 3800 > 5500 -81 1 stop80D 4200 > 5500 -56 1/3 stopFILTER CONVERSION Mired EXP. LOSS85A 5500 > 3400 +112 2/3 stop85B 5500 > 3200 +131 2/3 stop85C 5500 > 3800 +811/3 stopTable 13.1. (top) Color Correctioncamera filters. (Data courtesy of EastmanKodak.)Table 13.2. (second from top) Wrattenseries 81 and 82 filters. (Datacourtesy of Eastman Kodak.)Table 13.3. (third from top) The 80series.Table 13.4. (bottom) The 85 series.image control263