George Conklin <gconklin@xxxxxxx> wrote:
> I need to make negatives from some old Kodachromes. Since there is a
> contrast build-up in copying I need a color negative film with low
inherent
> contrast.
This film would be Kodak commercial internegative film 4325. I hope you
have a LOT of old Kodachromes to copy as this film is only available in 100
foot rolls.
>
> In the somewhat distant past I had a Bessler (I think that was the brand)
> copier with dichronic filters for the light source. For making color
> transparencies Kodak had/has a low contract reversal film available in
> bulk. Calibration was a long task with McBeeth (?) calibration slides and
> many test runs for color balance and the right amount of contrast reducing
> light fed back through a fiber optic.
Yep, those would be either SO366 or 6121 color slide duplicating films.
Exacting color match required for slide duping is a tedious process of trial
and error, even with sophisticated dedicated duping machines.
>
> This time around I'll use a simple slide copy tube with color negative,
and
> ye olde sun. The lab can fiddle with the rest.
As Emil Pozar <epozar@xxxxxxxxx> said, "Try preflash at -7 f-stops." It
works by raising the toe of the contrast curve with minimal change to the
shoulder. I have done slide to negative copies with mixed results. The
contrast does rise - more than I'd like - and sharpness suffers. I prefer
to use an inverted enlarger color head as a light source (constant,
adjustable and controllable) and fine tune color balance with the dial-in
filters. It takes a few tries, but if you have a volume of slides to copy,
it is worth the effort.
Have you considered scanning?
John P
______________________________________
there is no "never" - just long periods of "not yet".
there is no "always" - just long periods of "so far".
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|