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Discussion in 'B&W: Film, Paper, Chemistry' started by Jermband, Feb 8, 2008.
Could someone advise me on the best way to duplicate 4x5 negatives?
Kodak direct duplicating film work well
There is duplicating, then there is duplicating!
I don't think there is much in the way of duplicating films that are either affordable, or still manufactured.
I used to do quite a lot of duplicating of 4x5 film in a pro lab. We had two versions for our customers, one version was very expensive and we used a Kodak cut sheet film designed for duplicating, this was for top end jobs and clients with money.
The other method, is one I use still in my own darkroom. I just use Tmax 100 which by the way has an expiry date of 1991 on the outside of the 100 sheet box.
This method isn't exactly great, but it isn't too bad either. Basically I take a sheet of film and give it a pre-flash of exposure under the enlarger. I sit it in a special easel which is blacked out completely, instead of white or yellow to do this.
Next I take the neg that is going to be duped and place it emulsion to emulsion with the other sheet. Place a sheet of glass with anti newton etching on top, then make an exposure.
The neg is then developed as per usual to a time that has been worked out with empirical methods.
Now of course you end up with a transparency by doing this, so you repeat the method again and you end up with a workable negative, which is a reasonable facsimile of the original.
I'm not saying it's perfect but I copied an archive of 20 odd negatives from WWII for making prints from as the original negs were quite frail. The resulting 8x10" prints were more than adequate.
you could still find some duplicating fillm on ebay.
I think this would be a duplicating film: http://www.ultrafineonline.com/ulcotodufi.html
From what I understand it should make a duplicate neg, I've been thinking of trying this for making enlarged negs.
You could use ortho litho film too, couldn't you? It's suppose to be very very fine grain. Just develop it in paper developer for continuous tones instead of lith two-tone effect. It's less hassle than working with panchromatic film (speaking from experience of enlarged negatives).
There is a thread in "Contacting" which has been posted to for the last few days which can give you additional information although it is for enlarged dupes..
this is pretty much the same as kodak's professional duplicating film.
it is very slow, like azo paper, and requires a bright light to expose.
it will yield a negative from a negative ( single step ).
it processes in print developer.
Fine grained positive release film works too
It is orthochromatic and I think of it as a paper emulsion on a clear film base.
I contact print 35mm to 35mm I have on a 100' bulk can. I also have a stash of 8X10 shets that I cut down for special projects.
I also use ortho lith film developed by inspection in a low contrast developer.
Both of these steps yield positives. I have reversal procesed lith and fine grained with limited success. Usually I just contact it a second time.
I know this is not the same low contrast film meant for the job, but these methods suffice for my duped neg needs. The flashing suggestion is a good one; it should suppress contrast.
the better way to work with this film is to use Cold light ( the old blue one) comparing my tungsten enlarger light vs cold light give me a 6/1 ratio. When I need 60 sec with my tung light I just need 10 sec with my cold light.
I use, and teach my students to use, ortho lith film from Freestyle. Using a soft working developer like LC-1, or very dilute HC 110, or D-71 1+5 makes it easy. There is a recent thread on APUG or LF Forum about this.
Oops - hit the wrong key. That should be D-76 1+5.
Can you still get Fine Grained Positive film in anything but 35mm? I used to buy it in 8x10 from Photo Warehouse (Ultrafine on line) but they told me that nobody makes it anymore.
Ive been trying the continuous tone dup. film and John is right; it is seriously slow. They rate it at ASA 4 but I find it at least 3 stops slower in the darkroom. NZE: I haven't tried it with a cold head. Thanks for the suggestion.