Tri-color separation negatives with 35mm

[Marc Leest]

Dear all,

I want to make some tri-color gumprints using color separation negatives using ortho film:
The idea is starting out with 35mm color negative film. Then, using a slide copier, making three positives with unknown filtration on 35mm B+W film for channel separation. These three positives would be used in the enlarger with ortho film to have enlarged negatives.
Would this workflow feasable ?

thx for any tips, Marc

 

[henrysamson]

Years ago I used to make dye transfer prints. I started out with a 4x5 color negative shot normally. I then made my separations onto Kodak Pan Matrix film using a regular enlarger. Three were made one each through red blue and green filters. So it is somwhat similar to what you are doing. The Matrix film was processed in a tanning developer and they HAD to be developed together to ensure the contrast of the resulting matrices were compatible (to avoid crossed curves). Of course before doing this, tests were done through each filter with a step wedge to determine the exposure for each separation.

The result was three positives which is your goal. In this case each one was used with a different dye (cyan, magenta, yellow). One important thing to remember is that the easel used to hold the Pan Matrix film had registration pins and the film was punched. This assured alignment throughout the process. So, you may be on the right path. You'll just have to try it.