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View Full Version : Help me identify this.... film? paper? Seriously baffled.



Frozen film
08-01-2013, 04:19 PM
Found this stuff with a bunch of aerial photography gear at an estate sale along with two enlargers. All of the equipment with it dates to the 50's and 60's. I was able to find information on the rest of the gear, but this stumped me bad. I truly have no idea what this is other than the fact that it's light sensitive. Any information or suggestions on where to get information would be very helpful. Thinking it may be color reversal paper due to the "type r" and the fact that there was aerial slide film also in the lot, but not sure.

7234872349

Mike Wilde
08-01-2013, 04:34 PM
Likely slow speed orthochomatic film used for making printing plates. Comes in a 9" width; might be deisgned to allow printing of 8.5" final copy with edges of the material held in the printing frame.
Might be very thick gelatin silver mix, expose to UV, and the wash the unhardened gelatine off, then further harden the remaining gelatin in formadehyde, and use it fp photomechanical offset plates.


These are wild guesses. Pull some out in the aboslute dark, snip off a bit. Put some in paper developer for say 5 minutes in the dark, fix after dev, then lights on, to see how fogged it is.
Second part fix directly to see how dark the base is.

After that, expose a next snip to incandescant light for measuresd reproducable amounts under the enalrger - start with something like f/4 30 seconds, to see if you can put any back exposure onto it.

Go from there - scientific method. Hypothesis, test, adjust, iterate.

MattKing
08-01-2013, 11:04 PM
My guess would be similar to Mike's.

I thought that the shared use of PlateMaster on this link to a more recent, digital product was potentially informative: http://reprocentre.ie/wordpress/wp-content/uploads/products/CTP/Presstek/DPM34scHSC.pdf