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View Full Version : Duplicating Film as in-camera negative



Terence McDonagh
15-Mar-2006, 12:44
Has anyone ever tried to use duplicating film (some old SO-132, for instance) for in-camera negatives? I know the ISO will be very low, but is it even worth trying?

Mark Sampson
15-Mar-2006, 13:07
SO-132 is a "direct positive" film, it won't make a negative. It's so slow it reverses itself during exposure, and develops like an ordinary copy film, no reversal process needed. It's also blue-sensitive, not pan, so your tone rendition would be a little unusual. It was meant to make duplicate negatives in one step. If you use it as a camera film, be patient. Eventually you'll wind up with a b/w transparency original.

Terence McDonagh
15-Mar-2006, 13:40
Thanks. So if I understand you correctly, it would be like a very slow speed, ortho slide film in that it will yield a positive image? Could be interesting.

Any idea what kind of ISO to start experimenting with? I know Kodak's tech sheet says it's for use with "high intensity" light sources. Are we talking an ISO of 10? 5? 1? I'll have a lot of outdated film to experiment with, but don't want to waste TOO much time either.

Any idea how well this material holds up over time? This was stored in a cool place, but passed date in 1993.

Mark Sampson
15-Mar-2006, 13:55
Try putting a decimal point in front of your ISO number. It's *really slow* and I'd bet your exposure times will rival Daguerre's and Fox Talbot's, like multiple seconds in bright sun. But you'll never know until you try.

Terence McDonagh
16-Mar-2006, 15:18
Sounds good for some long-exposure shots I've been wanting to do. I guess I won't need a neutral density filter after all.

Collin Orthner
5-Apr-2006, 11:59
Good Day,
I realize this is a bit late, sorry. I came across an article in View Camera magazine from July 1989 written by Peter Goodman. He was using Ektachrome Duplicating film (6121). He mentioned that the colour balance varied widely from batch to batch. He rated the E.I. between 3 and 6, plus there is a reciprocity factor similar to Type L film(he did not say what that was). He showed a sample image made on 8x10 film which needed heavy filtration of 45M + 75Y with an exposure of 50 minutes at f/32. He recommends extensive testing on each batch of film to come up with the proper exposue and filtration.

Cheers,

BRIAN STEVENS
18-Apr-2006, 11:58
RE: B&W DUPE FILM.........THE PHOTO WAREHOUSE IN OXNARD, CA SELLS
B&W CONTINUOUS TONE DUPLICATING FILM.......4x5 8x10 etc.......
the phone # is 800 922 5484 and i was told they will be stocking regular b&w sheet films soon......
hope this is helpful.....................