C-41 Orange Base
I recently shot a roll of Kodacolor Gold from the late 80s and noticed the orange base was much paler than usual. I thought nothing of it other than "must have faded with age somehow" until I made some parodinal and tested it's activity on a piece of colour film leader (AFGAPHOTO Vista Plus 200), out of curiosity I scraped off the emulsion to see whether it was dyed orange as i'd always assumed, however it has a clear base.
Does this mean the orange layer is in the emulsion itself? Can it remain unactivated to use the standard C-41 like a slide film? Or was it pre-exposed to blue light at the factory to give the orange colouration?
Any info would be nice, it's not critical to anything, but would be an interesting topic to look into
The orange layer is part of the emulsion. It is a method of color correction called masking. Each C41 or C-22 film that has a different set of dyes has a different base color and the layers are rebalanced in speed to give the same results when printed.
If you scrape off the emulsion layer, the color goes with the emulsion and the base is clear.
There are also unmasked C-41 colour films.
Converted as types 135 and 120 is the Rollei Digibase CN200.
These can be crossprocessed to form a transparency film.
That makes more sense, that was you only have to make one type of base film rather than tint it. Is it a layer of orange dye or pre-exposed photographic material?
I have a couple of rolls of 200CN that I got for Christmas, looking forward to shoot it
The "classic" couplers are colourless.
By giving the coupler a hue of the same kind as unwanted hue is built up parallel to the formation of the image-foming dye, you gain a equal stain instead of an image depending one. The former can easily be filtered out.
This automated masking is employed in systems that need copying as in negative-to-paper.
This all is done because the image-forming dyes are not optimal, and the unwanted effect is enhanced during copying on similar material.
This automated masking is one major invention in colour photography.
Though, as hinted at there are materials that by choice do not employ such masking but to an extend cope otherwise.
Last edited by AgX; 01-05-2014 at 12:44 PM. Click to view previous post history.
Sponsored Ad. (Subscribers to APUG have the option to remove this ad.)
Thanks for the replies, cleared up things, I was originally wondering if it was possible to remove the orange layer through chemical means, but I'll stick with 200CN instead as it's just easier. Thanks