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RE: no 85, reciprocity failure?



>On Jan 29,  7:34, Tom Nottingham wrote:
>} Subject: RE: [TIG] no 85, reciprocity failure?

I got Rob's reply to Tom's reply, but Tom's original never arrived here. So
I may be repeating what 's already been said but . . . 

Reciprocity is to do with the effect of extremely long or short exposures -
like less than 1/000sec or over 1sec. Not an issue in cinematography except
in very high speed work. It's where the normal rule of "Exposure (and
therefore density) = Intensity x Time" breaks down, and it can affect
different colour layers differently.

But without a WR85, the blue layer of the neg is overexposed by about 2 1/2
stops compared with the red. The green is somewhere inbetween. Add in the
2/3 stop over that the DP added for good measure, and you have a severely
burnt blue layer. I'd fully expect some crossover as blue highlight contrast
would be flattened off - more or less depending on the contrast ratio in
each shot. 

-=+=-=+=-=+=-=+=-=+=-=+=-
  Dominic Case
  Atlab Australia
  email:  cased at atlab.com.au
  http://www.atlab.com.au/
-=+=-=+=-=+=-=+=-=+=-=+=-


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