View Full Version : Kodak Dry Plates

Drew Bedo
9-Apr-2021, 16:00
I have gotten these dry plates by Kodak. They are vbintage 1990s, and I am guessing they had something to do wit6h masking for etching chips (?!).

Anybody here have any experience? I am going to test a few plates but it would help to have an approximate ISO rating to start off with: 2,6, 12, 100?

Tin Can
9-Apr-2021, 16:09
I know Nothing!

But this thread leads a bit


Robert Opheim
9-Apr-2021, 17:08
We used a lot of ortho film when I was in High School in graphic arts for the pre-press work. I used to play with it at that time in the early 1970's altering full tone to line etc. offset negatives and positives. The ASA was really slow 8 or 12 ASA so I didn't try it in camera. At that time I was only shooting 135mm format. It was also on a thinner plastic base 4x5 film. There may have been a faster ortho film that was shot in camera. I remember developing it in D76 and of A and B developer. There is another thread see: https://www.largeformatphotography.info/forum/showthread.php?62700-Ortho-films-what-for

Drew Bedo
9-Apr-2021, 18:05
There is developer information on the box. What I need is some idea of how sensitive (or insensitive) the plates are.

Tin Can
10-Apr-2021, 05:19
The only way to figure out the speed, is to test in camera with a 10 stop pull of the darkslide

Do it under constant light of the type you will use

Everybody wastes one to test, may as well make it a useful test, as they are now rare

Asa 1-2-4-8-15-30-60-125-250-500=10 stops, you will find

I suggest Ilford PQ Universal Developer, water stop, any Fixer you have, I use TF5 for everything from paper, to plates to film

There is developer information on the box. What I need is some idea of how sensitive (or insensitive) the plates are.

Drew Bedo
10-Apr-2021, 06:08
Thank you T-C:

Ten stops on one exposure? If I could do that it would be great, b ut sounds complicated in terms of physically manipulating the slide and working out the exposure sequence. I will have to think about how to do that.

My initial thoughts were to do a test for ISO 25-50-100 on one plate in three sections: Slide fully open for say 1 sec, slide i/3 closed for an additional one second and slide 2/3 closed for two seconds.

An alternative that occurred to me was to use a split slide that has a 4x10 window offset to one side. This would allow one pano 4x10 shot at the top and another at the bottom using front Rise/Fall. Each exposure would be one full stop different. This technique might be left for later to refine the estimated rating or to refine development.

Wow: Ten stops in one go . . .ten exposures on one plate . . . .

We will be at the beach in two weeks which will provide consistent conditions over a wide open composition.

Nodda Duma
10-Apr-2021, 07:14
Drew I’d suggest starting at ISO 12 and bracket +/- 1 stop as initial test. Since they’re ortho you can develop them under a safelight...don’t pull them until they look too dark in the developing tray. Pick a developer to control contrast like you would for litho film. Good luck!


Jim Noel
10-Apr-2021, 08:18
These are orthochromatic plates so they work best with natural sunlight. They lose a lot of sensitivity in deep shade. I don't kno if the following will help, but maybe:

According to Photo Lab Index , Supplement No. 142
Kodak Process Plates Tungsten 2
Kodak 33 Positive Daylight 40
Tungsten 16

John Layton
12-Apr-2021, 11:17
I do believe that Wynn Bullock used a bit of ortho while working in forested areas...and while his exposures were quite long, they could be quite stunning, tonality-wise (especially in areas with accompanying low ground cover)...I think because of the high blue/green sensitivity - so foliage rode high and shadows were very natural and open, with skin-tones (he did some "forest with nude figures" also) very delicate. At any rate...its been on my bucket-list for quite some time now to try some ortho myself at some point...in just such forested surroundings, perhaps with a nude figure... or two! (or maybe not!)

Jim Noel
12-Apr-2021, 12:26
John I suggest you get used to Ortho film in sunlight conditions at al times of day before heading into the "forest". About 90% of what I use is Ortho, but I haven't been in a forest with it for several years. I am heading to the Redwoods Thursday and will take my UV meter to assist in determining exposures. I expect the effective speed to be from 1/8-1/4 usual daylight speed.

Drew Bedo
12-Apr-2021, 15:24
I will be testing at a sea shore lodcation in much the way recomended by Tin-Can. Don't think I can get ten steps on one plate though. I'll try 4 steps; ISOs 12, 25, 50 and 100. Have a spare dark slide marked off in quarters now, and have a glass plate loaded.

Processing will be by Blue Moon. I can't do this stuff at home.