Filters for color separation

FotoDave@aol.com
Fri, 19 Sep 1997 00:45:09 -0400 (EDT)

I am confused by color separation filters. What are the filters needed for
separating Ektachrome to b/w negatives? I have heard combination 25, 47, and
58, but when I checked KODAK's catalog, it shows combination 29, 47, 61 as a
set; but it also has 25, 47b and 58 listed as "color separation and tricolor
work." It doesn't say that the latter 3 form a combination though.

Also, are filter numbers pretty standard? If I buy filters from other
manufacturers with the same numbers, will those be the right ones for
separation? In another catalog I see Lee Tri-Color Filters, and it has #25,
47B and 58 as a set. Tiffen also has #25, 29, 47, 47B, 48, and 61, same
numbers as KODAK's. I don't know if they are the same thing though.

Are gelatine filters ok to be used with enlargers? I have a Beseler Universal
45. It is a color enlarger, so it doesn't have a filter rack before the
diffuser. I can place the filters below the lens, but are these gelatine
filters optically good or will they degrade the image?

Thank you very much in advance!

Dave S.