Friday, September 6, 2002, 4:48:37 AM, Mishka wrote: M> This is SO true. No color balancing can compensate missing blue chanel info. M> If possible at all (speed considerations/reduced ISO etc), 80A filter is M> very useful. Or a tungsten ballanced film (ectachrome 160t or similar).
>> Using an image editor you may be able to compensate for the lack of blue >> information to a degree however the image quality may suffer badly from M> noise >> artifacts. I can only agree. No amount of postprocessing will make it as good as with proper filter/film in the first place. That's the CICO rule (crap in crap out). This applies to digital as well, and so I think that to obtain best digital pictures under tungsten lights, one should use 80A filter as well (why you may ask? What the CCD probably does, when setting white balance, is assign different sensitivity to its R,G & B pixels. Probably the gain on the blue pixels is increased, when balancing to tungsten light, which of course pronounces colour noise, as most ccds would be calibrated for daylight). If I may add, another good point for tungsten balanced film in your situation is that it often is well adjusted against Schwarzild's effect (aka reciprocity failure), and many tungsten films do not significantly shift colours or density even in several seconds of exposure, unlike daylight films. Also, often a slower ISO film shows better real speed than a higher ISO film because the sensitivity of the higher ISO one falls faster because of the Schwarzild's effect is more pronounced with it, e.g. Tri-X 400 vs T-max 100. Good light, Frantisek Vlcek
