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Photo Forum / Film Photography / Darkroom / December 2004Auto-Positive Microfiche film
Hello all, I got some datagraphics autopositive microfiche microfilm. 100' of the stuff. I've been cutting it into sheets to use in my old Kodak 3A autographic folder. The base is too stiff to roll onto a reel. I have not been too successful getting an image out of it. I tried exposures from 1/15 to 30 sec (at f16) on a sunny day and development from 4 to 30 minutes in T-max RS. I have gotten a black rectangle (unexposed part of the film) with nothing inside. I can't figure out what I'm getting wrong in the topsy turvy bizzaro world of autopositive film. Not enough or too much exposure? Ideas I've had are: 1. Too much exposure leading to clear film. 2. Too much contrast from a microfilm leading to clear film 3. Strange fixing characteristics that wipes the image 4. Too little exposure (but why would I get the black rectangle? Any who, if anyone has some ideas, I'd like to hear them! Thanks. Daniel Goodale-Porter That film would be **very** slow. Try something like an ASA/ISO 8 (or even lower) setting on your exposure meter. > Hello all, > [quoted text clipped - 21 lines] > Any who, if anyone has some ideas, I'd like to hear them! Thanks. > Daniel Goodale-Porter > Hello all, > > I got some datagraphics autopositive microfiche microfilm. 100' > of the stuff. I've been cutting it into sheets to use in my old Kodak > 3A autographic folder. The base is too stiff to roll onto a reel. Does this material have a catalog number or official name? I plugged "datagraphics autopositive" into google with no luck. Kodak 2468 duplicating microfilm appears to be very similar to Eastman 5360 Direct MP film. I have used 5360 as a camera film. I found that 0.3 ASA exposures and nine minutes in straight Dektol gives nice looking slides. The name of the film might be helpful for looking up data sheets from which exposure can be estimated. > I have not been too successful getting an image out of it. I > tried exposures from 1/15 to 30 sec (at f16) on a sunny day I would expect that to you should have gone from serious under exposure to serious over exposure in that range. I'm really puzzle why none of them turned out. > development from 4 to 30 minutes in T-max RS. I have gotten a black > rectangle (unexposed part of the film) with nothing inside. That says over exposure to me. Given the extremely fine grain of these films, you might find that a film developer gives you brownish images, while a print developer should give black tones. This doesn't explain your results though. Are you using a safelight or complete darkness? Many of these types of films are ortho, but they may require a deeper red safelight than the common 1A filter used for Kodalith. I use a flashlight with a #25 gel pointed at the wall for a safelight for Eastman 5360. Peter.  Signaturepirwin@ktb.net I suspect there is a processing error. Depending on what this was designed for it may be quite high contrast film. Autopositive film makes use of a property of silver emulsions that results in reversal with very high exposures. This effect is rare in modern pictorial films which are designed to eliminate it but it can be accentuated by the method of making the emulsion. Such film gives a positive image directly on exposure and processing in a normal negative developer. However, most of this film was intended for document copying and is very high in contrast. Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com The box I have is a blue cardboard box with "Datagraphiix AutoPos" emblazoned on all sides. It was made by E.I do Pont de Nemours & Company Inc. Photo Products Department. It has an additional sticky lable with the numbers 3021 and 9122-2 stuck to one side. Not sure if that helps. > The box I have is a blue cardboard box with "Datagraphiix AutoPos" > emblazoned on all sides. It was made by E.I do Pont de Nemours & > Company Inc. Photo Products Department. It has an additional sticky > lable with the numbers 3021 and 9122-2 stuck to one side. Not sure if > that helps. I suspect it is quite old. I don't think Dupont has produced microfilm in recent years. The stuff is for computer output microfilm from a CRT. It is probably similar to Kodak COM DR Microfilm 2467. If it is, it is much faster than the duplicating films we have been talking about: closer to 25 ISO. This would mean that you had over-exposed it. The black borders are a good sign that the film still has life in it. Try 1/25 of a second at f/16 in bright sunlight. Peter. Signaturepirwin@ktb.net Thanks. I was going with painfully slow which could have been the problem. I'll make some new tests and keep you informed. Thanks. I was going with painfully slow which could have been the problem. I'll make some new tests and keep you informed. Think reversal film, like a slide, not enough exposure = black. This is a very slow material. Another post suggested EI 8 but I think that may be high. And if it reacts like most graphic arts film it may be even slower when used with conventional developers. We need to get a couple of lithographers to join the group, my own recollections of my one foray into lithography are pretty hazy after 30 years. Lith films are grouped into projection speed, pretty slow, like Kodalith and contact speed (even slower), no ISO's. Correct me if I'm wrong but I vaguely recall that this type of film autoreverses from true solarization. Signaturedarkroommike >Lith films are grouped into projection speed, pretty slow, like >Kodalith and contact speed (even slower), no ISO's. This stuff is to make direct dups of microfilm. As you know microfiche is in the negative and this film will direct print additional copies into the negative. Usually comes in 105mm rolls. Motion picture direct dup 35mm negative works the same way. It was manily designed to make direct dup negs form old 35mm nitrate base neg originals. It is very slow and designed to work under carbon arc or very blue light. It is not red or green sensitive at all. You can sometimes get this stuff in 35mm from tag end respoolers. It's about a ASA 1 in noon summer sun. It's alot less with indoor lighting or late day sun. Larry |
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