On Tue, 14 Sep 2004 19:03:53 GMT, Donald Qualls
wrote:

Roman J. Rohleder wrote:

Gregory Blank schrieb:


Macochrome is Color, E6, Fomapan R is probably some kind of bw movie
stock and not available in sizes beyond 135.

This is confirmed, and further it cannot be developed to a negative in
conventional B&W processing due to a colloidal silver antihalation
layer.

Both Color reversal and BW reversal first developers use a small
amount of a Silver solvent such as Thiocyanate to remove the very fine
particle silver in the AH layer. About one (1) gram should be enough.
If you make up your own solutions, try that out as a first test.

Look at the published formulae for first developers of reversal films,
both color and BW. That should be enough for someone as informed as
you have shown yourself to be.

The only practical way I know of to get a negative from Fomapan
R is to develop in a color developer with the same black dye couplers
used in XP2 or BW400CN type C-41 B&W films, then bleach and fix as for
C-41. For B&W positives, of course, you use the regular first dev,
non-halogenating bleach, reversal exposure, second dev, fix process that
would produce a positive on any B&W material -- but the bleach step is
mandatory to remove the silver AH layer.

Hmmm. Perhaps what I suggested, above, will work better and more
inexpensively.


Anyway Fomapan R is cool stuff.


Indeed - good sharpness and grain, nice tone, and stunning latitude
for a slide film.

Never tried it, but I might have to get a short roll and try it in my
Minolta 16 cameras once I have the resources to do reversal processing
-- using Diafine for a first dev should give EI 160 to 200, and grain
would be determined by the second dev, which could be a super-fine grain
soup like Microdol-X or Ilfosol.

I suggest you make up double strength batches of Diafine, as negatives
are developed to a lower Gamma than are reversal films. Diafine, as
it works for negatives, might be too weak. Again, note the use of
Thiocyantes in reversal first developers.

The second developer is usually not a critical item. All it has to do
is develop the remaining Silver, which is usually the slow, smallest
grains that are left in the emulsion after first development. They
don't clump as readily as the larger grains that get developed in the
first developer, and would be more easily and seriously affected by
solvents in any developer. The two you mentioned both have
significant solvent action, both from agents added and the high level
of Sulfite. Just use the formula given for second developer that is
published.

Heck, I knew one guy who opened some cans of Dektol and added
thiocyanate to the first developer and used the Dektol stright as his
second developer. He did this after testing to refine his procedures,
and I can't remeber what those refinements were, but I recall that it
wasn't much.

By the way, you'll lose speed on any reversal film developed as a
negative. It's the nature of the beasts. They are all based on
negative emulsions of about a stop and a half less speed rating. This
is largely due to the differences in their initial developers. Your
tests will show that to you.

In any event, your ideas are interesting, and so should be your
results.

Looking forward to hearing of them.

Robert Vervoordt, MFA