First post in this area, I've been lurking and have some questions.
I was wondering who really knows a lot about glass plate negs here on APUG?
Here is why, I have a Rochester Optical / Kodak imperial plate camera that in the 1970s and again in the early 80s I poured some emulsion on the scraped off glass left behind in the holders and took a few frames.
So when did glass plates go out of production? Is there a following of dry plate shooters out there who long for supplies? I know you can buy liquid light and pour your own negs, but might there be a market for pre made dry plates.
I ask this because my wife owns a glass company and I own a dry plate camera. 1+1= 3 (right?)
I don't know much about them, but while reading up on a thread regarding re-using photo bottles for beer, I found a write-up that old glass plates can't be recycled for re-use as glass plates because some image is retained in the glass itself.
i have been pouring and shooting ( or enlarging on ) glass plates since about 1986 ... off and on ...
i think slavich in the fsu is one of the, or the last maker of glass plates. kodak made tmx glass plates
up untill a few years ago, and they were primarily used for scientific photography -- microscopy and astronomy
because of the solid glass substrate instead of film. i always wanted to buy some tmax100 plates
but unfortunately they cost $400 / 100 plates while film cost around $50 during the same time ... so i opted
to coat my own instead.
i like the tonal pallet of plates and paper much more than film ... and they are kind of fun to make :)
if you decide to coat and sell them, let me know, as if they aren't $400 / 100 plates that is :)
In 1959 I worked for Dufay colour just before the manufacturing part was taken over by Polyfoto. A Most of the Dufay workers got jobs with Polyfoto from what I can remember they where using 7x5 Kodak P303 glass plates.
Ilford still have a glass plate coating line in use which uses a modern coating head, anyone who's been on a factory tour will have seen it demonstarted. However the cost of coating plates is very high and Ilford's production is mainly for the Nuiclear industry..
The last production of regular Ilford plates was some time around the 1970's I remember being given a box of outdated FP4 plates with my first LF camera in 1976.
I've recycled old (unuseable) glass plates as ground glass focus screens and even as glass inserts for Durst negative carriers. One problem now is that for health & safety reasons the minimum thickneess of glass sold to the public is 2mm (in the UK) which can be a little too thick for some plate holders.
I wasn't aware of the issue in the UK with thin glass. (Of course, truth be told, there are a whole lot of things I'm not aware of.) Is it possible to get thinner glass through other avenues, as with some of the more dangerous chemicals? You're spot on about the problem with some of the smaller format plate holders -- especially when a nice, thick coat of emulsion goes on. It would be a shame to rule out small plates because of glass, of all things.
You shouldn't experience any problems reusing unexposed plates. I've read of problems when exposed and processed plates were reused. Apparently, you could sometimes make out a faint image of the first exposure under the current image. This phenomenon was used by spiritualists to prove there were ghosts that could be photographed by someone with the right 'connections' to the Afterworld. I take that with a grain of salt, mostly because it's just too great a story, and because I haven't found any collaborating info in scientific publications (which doesn't mean it's not there yet to be found.) I've reused plates with no problem, but I don't use plates that have been etched and subbed before coating. It seems to me that may make a difference.
If you and your wife could supply pre-cut plates with baby butt-smooth edges in a number of thicknesses and sizes appropriate for a number of formats, and they were a reasonable price, I can imagine diy plate makers would buy. Right now, I think the attraction of the process is coating the plates oneself, but if you made a killer emulsion, that might very well change. I think there's room for the cottage industry in this arena.
Do you remember the source of the info you read about retained images? I'm just sure at some point, I'll want to see if I can make ghosts walk the earth :).
Thinner glass is available but just not from regular suppliers even green-house glass which used to be quite thin now has to be 4mm. There's a far greater chance of thinner glass breaking or cracking when being cut or in fact in use/storage.
It's a changing market a couple of years ago thinner glass was relatively easy to order from my local glass shop but his suppliers no longer sell anything less than 2mm.
I've found UK suppliers of thinner glass but it may be a case of minimum orders, buying as a business etc. I'll post back in this thread when I have details, meanwhile Ill check my plate holders.
Talking with my wife she shared that so much glass today has a slight green tint to it and perfectly clear looking glass is very expensive. I'll find out more about thickness options from her but in inches I think the most common thin glass is 1/8 in the US.
Cutting to size and grinding smooth grinding edges should not be an issue, they have great jigs for that and I think everything there comes out with smooth edges (cuts down on law suits, worker's comp cases and all) always supply a good final product.
There also might be a option to create ground glass replacements. I read the article here on apug about using coumpounds to grind/polish glass to an even frost look, and that may be kind of needed item. Just as long as I don't start causing a stir at her business, you know the Bosses Spouce thing can be distracting.
Love hearing all the input. Keep it comming.
The German online Photoshop/supplier Lumiere still sells Othrochromatic microphotography glass plates (40ISO) under the Webphota label http://www.lumiere-shop.de/index.php...0uq0u1lc5l3bkg
In the US Microchrome Technology still produces glass plates http://www.microchrometechnology.com...hotoplates.php
Agfa Gevaert still make APX 100 plates. However they are not cheap, I think it's over $100 for a box of 10 or 12.