Processing of Kodachrome 120

nickandre · Nov 28, 2008

And the only option for those filters is the square glass ones that cost $70 a piece? Would it be possible to duplicate that with another cheaper product like theatrical filters to achieve the same wavelength of light with the needed consistency?

Photo Engineer · Nov 28, 2008

There are a number of Wratten acetate filters sold by the square foot. Kodak used to stock them. They were not very expensive. Those are the only ones I know of. IDK if the theatrical filters will do the job. Kodak has posted the spectrophotometric curves of these somewhere on their web site. It may still be there.

PE

dmr · Nov 28, 2008

Photo Engineer said:
Could you use a spectrophotometer? I suppose so, but the wavelength might be too narrow and miss the sensitive peak of the dyed emulsion. Also, spectrophotometers tend to have low light levels at any given wavelength. For example, that 100 watt bulb behind it has itself divided up over all of the lines.

I really wasn't suggesting using a spectrophotometer to re-expose, but maybe apply the principle of the prism and slit to be able to get a known wavelength light. If you have ever seen the sample tube of a spectro, it's rather small and the illuminated portion is very small compared to the area of a negative.

Photo Engineer · Nov 28, 2008

DMR;

I have one here to make wedge spectrograms of my film. It is a Bausch and Lomb unit. The cut of the monocrhomater is usually 10 nm, which is too narrow for this type of work IMHO. It needs to be about 50 nm or more wide, centered on the lambda max of the emulsion sensitivity.

PE

kevs · Nov 28, 2008

*raises hand*

Might ultra-bright L.E.D.s meet your need? These have a relatively narrow frequency output and are available in RGB primary colours. Also, they're inexpensive, easy to power and work with. I'm currently playing at converting an enlarger to an L.E.D. light source, which prompted my thought.

http://en.wikipedia.org/wiki/Light-emitting_diode

I'd love to try 120 K64 in my Bronica... not that i have any... *le sigh*

nickandre · Nov 28, 2008

I found a few on ebay. I'll look around.

Anyways, the LED method was discussed and there were several things that came up. One it may not be on peak with the sensitivity curve of the film, risking crosstalk. Two it would be difficult to get an even field of light to spread it out equally.

Looking at the chemicals, I'll make sure I can get an image before I go wild. I have a few but not anywhere near all of them.

Photo Engineer · Nov 28, 2008

Remember that several months back, somone posted some Kodachrome that was said to be hand processed at home.

PE

nickandre · Dec 30, 2008

WELL, I have the couplers. I processed pieces of regular film in the developer solutions and made colored pieces of film. However, the paper developer which the couplers are designed for works slowly and irregularly.

I think the next test is to shoot a roll of B+W and see if I can get a good negative dye image.

I asked dwaynes about chemistry and they said "talk to kodak." I'm a little worried that the minimum order quantity for chemistry is "a hell of a lot" for "an arm and a leg." Any suggestions on chemistry?

Photo Engineer · Dec 30, 2008

The patent is published. The authors are R. Bent and R. Mowrey. The couplers and developers and all ingredients are commercially available. I can't afford them. Good luck.

Your best bet to start is to make tricolor positives by this method and laminate them to see how they look. See the post elsewhere on the results of another person. I am sorry I lost the URL but the truth is out there somewhere.

PE

John Shriver · Jan 2, 2009

My own hunch is that the best use for PKR120 is to slit it down to 35mm wide, and use it on 828 spools in a Bantam camera. Then you can send it to Dwayne's for processing, since it will run on the 35mm machine. Well, they might want to charge the push fee, since they may not trust your slitting, and might not want to run it on a big spool with anyone else's film. They might be more easy-going if you sent 10 rolls at once.

uwphotoer · Jan 2, 2009

I have 10 rolls of unexposed Kodachrome 120 i would love to shoot

nickandre · Jan 3, 2009

Say, if anyone has either a wratten 98 or a wratten 70 (or both) they would like to donate to the cause, I would greatly appreciate that.

Photo Engineer · Jan 3, 2009

I have a 98, 99 and 70, but there are substitutes. the 29 can be used for the 70. Exposure time will be about 1/2 that of the 70.

I hate to not donate, but I use mine for separations. Sorry.

PE

accozzaglia · Jan 19, 2009

For matter of record and easy retrieval to anyone interested:

Listed under query "bent mowrey color" (also same results when query is "bent mowrey kodak"):

Reversal Color Photographic Processes
U.S.P.T.O 3,658,525
Dec 3, 1970
http://www.google.com/patents?id=WlQrAAAAEBAJ&dq=mowrey+bent+color

Photographic Elements Containing Color-Providing Layer Units for Amplification Processes
U.S.P.T.O. 3,834,907
May 24, 1972
http://www.google.com/patents?id=gxQtAAAAEBAJ&dq=mowrey+bent+color

Color Photographic Processes
U.S.P.T.O. 3,656,950
Dec 3, 1970
http://www.google.com/patents?id=vCs7AAAAEBAJ&dq=mowrey+bent+color

List of others (outside of Bent and Mowrey query) directly referencing Kodachrome:
http://www.google.com/patents?spell=1&q=kodachrome&btnG=Search+Patents

Use this posting as a bookmark reference tool. -A

Photo Engineer · Jan 19, 2009

The first reference above gives all of the process formulas for Kodachrome. The others are irrelevant. Some, such as the patent by Vern Bissonette and the one by Pranab Bagchi don't even pertain to Kodachrome AFAIK.

PE

accozzaglia · Jan 19, 2009

Just sayin'. I ran the above query per your terms. Whatever comes up comes up. Now it's here. -A

Ira Rush · Jan 30, 2009

I too would have some rolls to be processed!

tiberiustibz...

If you really can get this going, I too would have a couple of rolls for you try out...

Best of luck, keep us posted!

Ira

Processing of Kodachrome 120

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