Gelatin Failure Kodak in 70's?

[perkeleellinen]

"Kodak Company, you know the people that used to make film"

Would be nice if you could correct the poster on this also.

[Photo Engineer]

Is modern film still made using gelatin from animals? Isn't there a synthetic product that would be as good or better? No, this isn't an animal rights thing, I'm just curious. In the early 70's I used gelatin cubes to brew up an emulsion batch from a formula that was from the early 1900's. Coated on to 4x5 glass plates it worked remarkably well but was REALLY slow. I wish I still had the formula. It was lost many moves ago but I still have one surviving glass plate. A little off the original topic but I thought it would be fun to share.

Wade;

Gelatin is still used in photographic products. Some synthetic binders are added for many purposes, but gelatin remains the major binder.

Old formulas used the active gelatin referred to in the original post. Overactive gelatin was the problem that led researchers at Kodak to discover sulfur sensitization. Since then, most all photographic grade gelatin has had the sulfur compounds removed. This makes them give us a slow emulsion unless a sulfur sensitization step is added.

I suspect that if you carried out this extra step you would double or triple the speed of your emulsion.

PE

[Ian C]

For an account of the sulfur-contaminated gelatin due to the donor herd consuming mustard grass see

George Eastman—a Biography
Elizabeth Brayer
©1996 Johns Hopkins University Press

http://www.amazon.com/George-Eastman...p/0801852633#_

It is a large book with a great wealth of information about George Eastman, the company he founded, the difficulties in making practical emulsions, making and selling cameras, and how Kodak became the greatest maker and seller of photographic materials in the world.

[Grif]

Hi,
Here's the response...

I was teaching photography back then and we were developing slide
film. On several rolls the emulsion slide off the base. That is the
story I got back from Kodak. That was before the internet, so who
knows if it was true.

[Grif]

Oh,,, it's getting better all the time... The latest, the guy posting the stuff on the other list is an old photo teacher, now teaching computer sci. Claims to have really enjoyed processing Kodachrome and Tri X in the darkroom.

Did they ever have a process to do Kodachrome at home or in a very small hand tank lab?

[Photo Engineer]

Oh,,, it's getting better all the time... The latest, the guy posting the stuff on the other list is an old photo teacher, now teaching computer sci. Claims to have really enjoyed processing Kodachrome and Tri X in the darkroom.

Did they ever have a process to do Kodachrome at home or in a very small hand tank lab?

There was never a kit to home process Kodachrome. It could be done by hand, but was never ever released. This guy appears to be making things up! Sorry.

PE

[Gerald C Koch]

The Kodachrome process was published in the Dignan Newletter many years ago. It contained the formulas for all the various baths. AFAIK, only one person attempted it and I don't don't know if they had any success. However, the two people who developed the process and sold it to Kodak were professional violinists and had no engineering degrees.

[lxdude]

Hi,
Here's the response...

I was teaching photography back then and we were developing slide
film. On several rolls the emulsion slide off the base.

Tell him it was supposed to do that. That's why it's called "slide" film.

[Photo Engineer]

The Kodachrome process was published in the Dignan Newletter many years ago. It contained the formulas for all the various baths. AFAIK, only one person attempted it and I don't don't know if they had any success. However, the two people who developed the process and sold it to Kodak were professional violinists and had no engineering degrees.

If you look at the patents, Mannes and Godowsky had invented a chromogenic film in which two layers were coated with one layer on one side of the film support and the other layer on the reverse side of the film. This gave a 2 color image when developed in 2 color developers. They were so close, but did not have a 3 color version. Their materials were supplied to them by George Eastman.

He finally invited them to join Kodak Research, which they did, and there they worked with a team of engineers to perfect what we now know as Kodachrome. That process required 3 developers, 3 re-exposures, and 3 bleach baths for tricolor imaging. It was the first Kodachrome released.

IDK when this sequence changed but the new process required only one bleach and two re-exposures.

In any event, even with publication of the formulas, the chemistry was hard to get and the process required up to 3 hours for the old one and about 1.5 hours for the new one. The old process required 3 processing machines and the new one took only one. All of these processes required exacting procedure if done by hand.

You are right that only one or two people have attempted it, and the one result I saw posted was a far cry from anything you would want to show anyone. It was nevertheless a good effort.

I would applaud anyone who got as far as having 3 colored images on a piece of Kodachrome film no matter how off color or poor the results might be.

PE

[lxdude]

A thread on another list (metal lathes)

To keep him on the list topic, see if you can get him to tell you about the time he put an Acme-Gridley RB-6 bar machine in his basement. Or the time he built a full size steam locomotive with only a 110V Lincoln welder, a Bridgeport, and a Hardinge chucker.