Contact Printing Glassgreenspun.com : LUSENET : Large format photography : One Thread
A friend and I have entered the world of 12x20 format, and in discussion with another photographer, a comment was made. He encouraged me to find "optical glass" for the contact print - this glass he claimed was absolutely flat and had a better transparency then regular glass. He had suggested talking to an office supply compnay and asking for glass taked out of broken copiers.
I had been intending to get a sheets of 1/2" plate glass, and use that in conjunction with a sheet of high-density foam for contact prints, but if "optical glass" would be better, I'd pursue that.
Any thoughts, comments of suggestions?
Eric Boutilier-Brown Halifax, NS, Canada
-- Eric Boutilier-Brown (firstname.lastname@example.org), June 09, 2001
I can't believe I never thought of that! Old copier glass! Great idea - except that often old copier glass has scratches and dings and *yech* on it. Still, great idea if you find a clean one!
Meanwhile - I have been using a 1/4" thick piece of 18" X 20" glass I got from the local glass shop and it works fine. I insisted that it had to be flawless - no bubbles, scratches, ridges, pock marks etc. but they managed. I attached it to an old piece of counter top with the hinges for an "entertainment center" glass door. I think all together the cost was $39.00
-- Sean yates (email@example.com), June 09, 2001.
Two oversize sheets of 1/4 inch plate glass will work fine. The top sheet has to be perfect of course, the bottom can have small imperfections. The two perfectly flat surfaces make excellent contact for the negative and paper sandwich. I do all my silver prints up to 12x20 inches this way--for 1220 platinum prints I switch to a vacuum easel.--
-- Carl Weese (firstname.lastname@example.org), June 09, 2001.
Well gee-whiz Carl, it never occurred to me that another sheet of glass would make a great base for contact prints. Can't wait to try it. THANKS.
-- Dave Richhart (email@example.com), June 09, 2001.
Eric - I contact print 12x20 negs with a clean piece of 1/4" plate glass on top of a piece of melamine (basically a piece of particle board with a smooth white surface - the kind used in making kitchen cabinets). It's flat and dust-free. Works great and costs little.
Welcome to 1220! You're gonna love it!
-- Mark Parsons (Polar@thegrid.net), June 10, 2001.
The quality of the glass used has very little effect on a contact print, since the image sharpness is governed by the closeness of contact between the negative and the printing paper/film. Ordinary float glass is more than good enough quality, and inclusions such as bubbles are rare in commercial glass these days. Real optical quality glass is far more likely to have bubbles in it.
Don't kid yourself either, that scanners and copiers use anything better than plate or float glass in their platens.
-- Pete Andrews (firstname.lastname@example.org), June 11, 2001.