Questions regarding a sealed box of glass plate negatives

[Cameron Cornell]

May 7, 2018

A friend just gave me this sealed box of 5x7 glass plate negatives. Is there any chance that I could capture an image on these?

I have a 5x7 ROC Cycle Poco No. 5 with the original glass plate holders. The camera is effectively new old stock. It has no signs of wear whatsoever, not a single scuff on the leather case, and the shutter is accurate at all settings. Anyway, I've always shot film with it and it's cousin, a 5x7 ROC Pony Premo No. 6. The original holders have just sat in the case.

Could I load the holders with these plates and have any hope of capturing images? If so, does anyone have any advice on exposure and processing? I have absolutely no experience shooting or processing glass plates. I've made prints from hundreds of glass plates, but I've always only shot film in my own work.

I would appreciate any thoughts or advice.

Cameron Cornell
Washington State
www.analogportraiture.com

[Pere Casals]

Just spend a plate making a calibration, this is quite easy, no luxometer needed, take a relatively long exposure (metered 2s) but pull the dark slide only (say) 1/5 of the legnth, during the exposure pull the dark slide to obtain say 5 strips with different exposures, in a way that the first one will have some +2 overexposue.

Use a low fog developer, HC-110 is recommended for old stuff, also Benzotriazole can be added to control fog.

If emulsion separates from glass you may want to develop at low temperature with accordingly extended times.

hmmm, sure that those plates are in better shape than the DIY dry plates I make

[Nodda Duma]

Pere has a good suggestion. I would add that you should set your aperture to f/16 to make the test strips he suggests.

Dev temps at 65-68 should be ok. Try dilution B if you use HC-110.

[Robert Brazile]

Echoing the above, plus: I recently bought about 5 boxes of the same plates (except mine were Tri-X -- pretty much the same vintage and boxes, though). I have found that a) you certainly can get an image, and b) some of them have a fair bit of mold growing on them, presumably from how they were stored. Not all of them, and the ones that are clean do OK. A little loss in sensitivity, but not a lot. Try them and see!

Robert