Wow Scott thank you. That was super informative! And fascinating. So, just for the fun of it let me ask, what happens if you process kodachrome in C41 chemistry? Anything? Mud? I'm just starting out doing my own processing and I cannot get enough of the chemistry. Thanks again!
On Tue, Apr 30, 2019, 5:23 PM Scott Dorsey <[email protected]> wrote: > Oh, you could probably get a K-14 line running. Dwayne's Photo had one > running a few years ago and still has the analytic chemist on staff > although they don't have some of the other people on the line. > > The problem with K-14, which is also the wonderful thing about it, is > that the dyes are not in the individual film layers. So you have to > develop it to B&W images, then bleach out the silver, then expose it to > red light to get a positive latent image on the top red layer, develop > it into B&W images, attach a red dye to the developed silver, bleach > out the silver, expose it to green light to get a positive latent image > on the green layer, develop it into B&W images, attach a green dye to > the developed silver, bleach out the silver, expose it to blue light > to get a positive latent image on the blue layer, develop it into B&W > images, attach a blue due to developed silver, bleach out the silver, > then remove all residual halides and harden the emulsion. > > This is leaving out all the stop baths and clearing baths. > > So you have three B&W developers involved, all of which are designed to > have -slightly- different curves and which have to be kept under control > by a chemist to make sure they hit the curves perfectly. If you think > crossover on E-6 is a nightmare, this is way worse because you have > independent control over everything. > > Then you have three color re-exposures which have to be done precisely > and cleanly. The process control is very elaborate. Very small changes > can effect color a lot, so you are pretty much stuck with a big roller > transport system and nitrogen burst agitation. The one that Kodak had > in Hawaii was over two miles long from end to end. > > With E-6 pretty much all the chemicals can be made up from common reagents > except for the color developer. With K-14 you have all kinds of dyes and > dye couplers that have to be synthesized specifically for the K-14 lab. > It's something that can be done, but it's nontrivial. > > Oh yeah... and to do all of that process control, you need not only to be > able to do constant titration but also to run pc strips... and Kodak is not > going to sell you brand new Kodachrome pc strips anymore. I suspect that > running out of strips is what finally got Duane's to shut their K-14 line > down. > > The cool thing: because the dyes are added in after the fact and aren't > part > of the emulsion, you can use a much wider variety of possible dyes when you > design the process.. dyes with a wider color gamut and much better > stability > than conventional Kodak-process color films. This is why in the 21st > century > the one Kodak process that should have survived into the digital world is > Kodachrome because it is so valuable as a long-term archiving material. > --scott > _______________________________________________ > FrameWorks mailing list > [email protected] > https://mailman-mail5.webfaction.com/listinfo/frameworks >
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