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Discussion in 'Silver Gelatin Based Emulsion Making & Coating' started by pjwaffle, Oct 6, 2008.
Hi, does anyone know the formula for kodachrome?
Kinda sorta yes! But then there are at least 4 formulas or more that are/were current and they each use 3 emulsions.
Ron: Maybe he's wanting you to make it at home. Or maybe we could lease a little corner of a decommissioned facility ... you coat, I'll process.
It's a deal! I'll shoot!
Da*n, I wanted to shoot too!
Its hard to make the film when you dont have the emulsion formula...
Just curious... I probably won't even make it.
They are 9 Br/I emulsions coated in thin layers with very specific sensitzing dyes used that adsorb to the grain and survive the process. Making them would be a pain, sensitizing them another pain, and coating them would be a miserable job. After the 6 - 8 layers needed, the yeild would be less than 20% IMHO due to defects.
OTOH, you can use a one shot 3 color camera and make 3 RGB positives that can be processed in each of the C/M/Y color developers of the Kodachrome process. Then you laminate all 3 together and you have a very nice transparency. Much easier.
On the plus side, either route would give you a 4x5 Kodachrome transparency! (At great expense in time and money)
OK, I know the C/M/Y developers probably aren't available at my corner photo shop, but how hard are they really?
The availability of chemicals today is far superior to the past, and the availability of surplus equipment is also far better. Assuming that one has a fairly solid technical background - not really an unusual trait in the group that reads stuff here - there's not much I would put beyond the capabilities of a bunch of dedicated enthusiasts. It might not be all that economical, but if economy was all that I cared about I'd pitch every film camera I own out the door today and go completely digital. That's not who I am, nor who most of the other people here are either.
So, let's scheme this out shall we. After the gigantic discussions the past few weeks about Kodachrome and how to rescue it, this may be the answer. Just do it ourselves. After all, Sergei Mikhailovich Prokudin-Gorskii simply used 3 color separation and look at some of his stuff.
The developers are currently available and have been mentioned many times here on APUG. I don't have the reference, but they are basically color developers and couplers mixed to give C/M/Y images just like Kodachrome. Any B&W pan film can be used for exposure and lamination is simple.
I have no idea what the stability of the dye images are as I know nothing about the couplers chosen.
Perhaps someone would look up the reference here and post it or refer you to it.
Hi, What kinds of equipment do the factories use?
big kinds. I'm curious as to the layers. I thought kodachrome was the simplest of color films? It has the anti curling, blue sensitive, yellow colloidial(w/e) silver filter, green sensitive, red sensitive, base, and remjet. what am I missing? The sensitizing would have to be fairly exact...very exact. I tried the color separation method and couldn't find the color developers so I photoshoped to the finish. It was fun nevertheless...
I can't say about Kodak, but I have done a little work around Fuji coating lines. While it isn't rocket science from an industrial machinery perspective, it is a *LOT* to handle for a small time operator. And I'm a machine kind of guy, not a chemistry kind of guy. I know how to make a machine do what someone tells me it should do, but they have to figure out the process for me. However, the Fuji coating process is not trivial for a mastersheet. I doubt Kodak's is any less intensive.
My real interest is on the other end, specifically the possibility of using a tri-color separation set of 4x5 sheets and develop them individually in the three Kodachrome developers to create a handmade 4x5 slide.
I don't think there's any commercial potential for it, there sure could be an art potential.
Michael - you should talk to Wildbillbugman - he's working on making panchro B&W emulsions to put in his tricolor-neg camera to make color transparencies on glass, I believe.
Kodachrome layers /OC with UV/Y/IL + yellow dye/Fast Magenta/Magenta/IL/Fast Cyan/Cyan/Support/Rem Jet/
The fast and slow layers are often combined in slow products but separate in fast films. The machine is huge and a discussion of this is on the Emulsion and Making forum here with photos of a small scale prototyping machine. You may wish to look at that.
I have, in fact, been following the threads. For the moment I'm interested in using commercially available emulsions. I think making my own emulsions is a bit beyond where I want to go for a while.
I am, however, starting to read material on the Kodachrome developing process to see how one can home grow it. This thread has sparked my curiosity.
Obviously, dealing with three different physical pieces of film makes a lot of the issues in the KR64 product moot. I.e., there's no backing to worry about removing, you aren't obliged to protect one color layer from the others during processing because they're physically independent, etc. In fact, there isn't any reason you couldn't do the different colors on different days since you've got them physically separate.
Now, how nasty is the process, and how likely am I to be able to control it properly at a cost I can afford?
The process uses a high pH color developer (~11 - 12) that is not very stable so you might consider it a one-shot. OTOH, the rest of the process is normal. So, if you pick a normal B&W film and process in the normal negative developer, then the rest of the process is a breeze.
Won't the film base get in the way? Three emulsions with a few mills of plastic between them would seem to result in a fuzzy result if not looked at dead-on.
Laminate 2 of them face to face, and one to the back of the sandwich. That way you get a total plastic laminate.
In any event, the old timers used it and under normal viewing conditions via projection, didn't seem to complain. OTOH, maybe color was so novel to them they were awed! IDK. Try it!
PE, your messages are always technically refreshing, with a small dose of praticality stirred in for flavor. Thank you.
Earl Dunbar, do not promise something that you may not be able to deliver. The best that I actually have been able to do is to admit that I really do have most of the equipment that I want now (it is a multi year accumulation), and there are only a couple more lenses and some accessories I would like to find. I can do almost anything I really need to do now, from 16 mm through 35 mm and 6 x 6 and now on up to 4 by 5. In fact, I have wondered if this feeling of satiation with camera equipment is real, or normal, or if I should be seeking the counsel of a professional camera merchant to see if this belief or condition can be eliminated or at least reduced.
Thanks Ralph, but I left out the Newton ring problems and everything else in my last post to make it look simple. Nothing every is, but a shake of talcum powder might help my last post out.
Well, the high pH doesn't really bother me, and unless the one-shot cost is prohibitive using it that way makes perfectly good sense to me. After all, I use B&W developer one-shot, and the thread about one-shot fixer has me thinking, too. What's the harm in adding a one-shot color developer.
Can you point me to a few references about how this is done?
My first thinking is that there has to be a 3 part separation, and the cheap way, if the filters are the right colors, is to just buy an old dichronic head when one goes by on fleabay and steal the filters out of it. Of course, I don't know that those are the right colors for the separation. They might be the complimentary colors instead of the ones required.
Another thing that confused me in a few of the Google hits I found last night was the references to two part Kodachrome instead of three part. I guess it was something like red and green layers the way some laser displays have a red and green laser. Can you really get all the colors from that? If so, then it seems you could get a complete transparency in a single film holder. Two exposures and your ready to roll.
Obviously this isn't going to be any good for the horse races since at present I'm not thinking of ways to shoot all three simultaneously. I couldn't find anything helpful about robbing an old three color prism from ancient TV cameras with Vidicons, and I don't think new TV cameras work that way.
I guess I'll have to get the models to stand still.
I have a 1939 photography magazine (Minicam ?) where references to color photography involved 3-plate cameras and dye-transfer printing. A standard joke was not knowing which way up to hold the camera.
Though, IIRC, projection was the usual method of viewing:
Neat article on early color, including Prokudin-Gorsky
It's worth reading D.A.Spencer, Colour Photography, ? late 1940's, he give a good breakdown of all the colour processes including tri-colour etc.
Tri color cameras are quite popular on the dye transfer forum:
and dye transfer is described fully here:
Methods are described in "History of Color Photography" by Friedman.
The 3 color developers are available in kit form from some dealers. Ian has posted the reference in several threads here.