I was inspired by the earlier post 'Are you using your plate camera?' I haven't taken a picture with a plate camera for a while, but I won two 2 1/2 X 3 1/2" plate cameras on eBay about a year ago. Never did anything with them... until today One is a budget cameo camera. Reasonable condition but humble lens and shutter. The other is an ICA - must be 1920s as it has the pentagram as the manufacturers logo. Annoyingly ICA put the name of their cameras on the strap - and of course the strap has been replaced, so the camera is now anonimous. I've found that catalogue of ICA cameras from 1925 by googling - and they made about 100 different cameras!!! It is superficially like an Ideal, but without the rack for focussing or the frame finder. It is like a budget Ideal, maybe - but strangely it has a compur dial set shutter and a Tessar lens, so not so budget optics. Anyway, to get to the point - I happen to have a fair collection of unexposed glass plates. Over the years I have established that most of them are now completely unusable (hardly suprising) but some of the slowest ones have survived. A packet of "Wellington" process plates from about 1920 were as good as new, not a trace of fog. I expect the speed of about 1/2 ISO probably helped Today (or tommorrow) I thought I'd try out some Kodak P.25 plates from the 1950s in the ICA. I assume these will be slow, so may have something left in them? Unfortunately I have no exposure details for these plates. I've tried googling, but "P.25" gets interpreted as a document page number, so mostly anything with the word "Kodak" is displayed. I can't track down any Kodak plate info Now. Does anyone know an approx ISO rating for these? OK, they might not be exactly as per spec anymore... The original ISO rating might not be so relevent, but a rough starting point would be useful. I only have a few so can't afford to waste too many plates with experiments to determine speed.