Developing old glass plates

Hi everyone!

I have noticed that on this forum there are several people who develope

old film they have found in their "new old" cameras. I just found 12

exposed but undeveloped glass plates in a camera I just got. I only

ruined one of them and the rest of them are untouched. How do I develope

them? Any help is appreciated. The one I ruined had a grayish layer on

the other side and some blueish on the other.

Jani

First, if you just opened a holder and noticed the plate, as long as you closed it quickly, you may not have done too much damage. Most glass plate emulsions (I am remembering photo history here, not personal experience, so I could be completely wrong) are pretty slow. However, if the plate has been sitting on your desk under your desk lamp, I'd say it's cooked.

Here is a link to a site that has good information usually. Looks like you can use a paper developer. <a href="http://www.alternativephotography.com/process_dryplate.html" >www.alternativephotography.com - Dry Plate Processing</a>

Be sure to scan the images if you get any and post the results here. Very cool find you have, especially if someone's great grandmother or favorite cow is on one of those plates.

I would develop them in a tray, one at a time, with straight D-76 for perhaps 12-14 minutes. Compleate darkness in the darkroom, as we don't know if the emulsion is ortho- or panchromatic.

The speed of the emulsion could be anything from 6 to 200 ASA.

The "grayish layer" is the emulsion. The blue layer is the antihalo-coating, just as films have.

Jorn Ake wrote: "Looks like you can use a paper developer."

That's for the home made glass plates, not for the more modern style plates we are talking about here.

What do you mean by modern? These plates are about 80 years old. And according to the amount of dirt and dust on the holders, I think no-one

has opened them, so I only ruined one of them.

D-76 would definitely be fine -- but you may find you need more like 15-20 minutes. Developing times were really long in that era.

Don't be sure anyone ever exposed them. Do the dark slides have any exposed marking on one side?

"What do you mean by modern? These plates are about 80 years old."

I meant that I don't believe that the plates have the type of simple emulsion as described on the Alternative Photography page. They could have an orthochromatic emulsion as well as a more modern panchromatic type (like Plus-X).

Old style emulsions are a modernity today. Take Efke as an example. And you don't soup these films in a paper developer.

If a camera is 80 years old, the glass plates in it's holders don't have to be 80 years old. They could be from the 1930's or even the 50's or 60's. Ok, glass plates became less popular after the mid 30's, but they were still available. Kodak stopped making T-max glass plates just a couple of years ago.

In fact, you *can* develop glass plates (or even absolutely modern film) in a paper developer like Dektol -- which used to be sold as a "universal" developer for both film and paper, though it was usually diluted more for film than for paper, to slow down activity. However, for really old plates I'd be very strongly tempted to use HC-110, probably Dilution B at six minutes for the first plate, then adjust time for the others after seeing how the first one goes. The HC-110 will tend to control fog from age, and give a better chance of being able to print or scan any image you might find.

FWIW, when I bought a bunch of plate holders for my Zeiss Ideal a few months ago, the first one I opened still had a sheet of film in it -- a tape label suggests it might have been exposed in 1964. Unfortunately, all the others were empty...