Duplicating LF negatives

ntenny · Apr 3, 2023

I’ve inherited some family negatives on nitrate stock, 4x5 through 8x10. They’re in good condition, but I know I can’t rely on them to stay that way, and then there’s the fire danger, so I need to find a way to archive them in a stable and safe format.

I would like to end up with negatives, so I can print from them optically. This may not be practical to do for all the images (there are a few dozen on nitrate), so I may end up keeping scans of the ordinary ones and negatives of the best few.

As far as I can tell, I have three options for producing negatives:
1) pay for drum scans followed by a print-to-film process;
2) do my own darkroom work to contact print them to interpositives, then to duplicate negatives;
3) do my own darkroom work to contact print them into a direct-positive process.

Obviously #1 is the easiest, but it’s prohibitively expensive to use for more than a few sheets. I only found one lab that can do it (BowHaus in Los Angeles).

#3 looks hard. I’ve done a little b&w reversal before, found it fiddly, and never got really good results.

So I’m curious about #2. How hard is it, assuming I’m a competent but not exceptionally detail-oriented LF worker? Past threads have seemed not to have consensus on what film to use (my impression is either pictorial ortho or ortho litho, with film developer), and I don’t know where to start with exposure. I guess I’d like a brief practical guide to this process.

Also, are there any options I’m overlooking—again, assuming I want to end up with negatives?

Thanks
-NT

jeffreyg · Apr 3, 2023

If you can get X-ray duplicating film it will be easy. Either contact print or enlarge if you want. Check with your dentist or search online. It isn’t necessary to make an inter-negative wth that. I have used that for many times to make enlarged negatives for platinum/palladium printing. The results are excellent. The film is not too cheap but easy and less than drum scans and only one generation as opposed to first making an inter-negative.

ntenny · Apr 4, 2023

jeffreyg said:
If you can get X-ray duplicating film it will be easy. Either contact print or enlarge if you want. Check with your dentist or search online. It isn’t necessary to make an inter-negative wth that. I have used that for many times to make enlarged negatives for platinum/palladium printing. The results are excellent. The film is not too cheap but easy and less than drum scans and only one generation as opposed to first making an inter-negative.

Thanks. It looks like there are a couple of sources, albeit in funny sizes. How do you develop it to a positive—conventional film developer?

-NT

jeffreyg · Apr 4, 2023

You don't develop it to a positive what you get will be a negative. That negative can be archived and/or contact printed or used in an enlarger to make a positive. There are developers and fixers suitable for x-ray film as well as traditional film developers. The duplicating film is generally slow and I use it to enlarge negatives so I do as I would making a traditional darkroom print. Remember that it is like a transparency so more exposure will give you a "lighter" negative and "darker" print from the duplicated negative. You can burn and dodge just as needed. It does come in 8x10 as well as the other sizes you saw. I expose , develop, water stop (no acid), fix and wash. No other special steps. Your duplicated negatives will be as sharp as a print if not sharper since the film has very nice contrast and wide tonal range. I was originally using it in my dental practice to duplicate x-rays to send to insurance companies with claims and tried it to enlarge 120 and 4x5 negatives to make pt/pd contact prints. After a few tests i was pleasantly surprised as to the quality of the images I was getting. Several years ago I was approached by the (now deceased) Cuban-American photographer Mario Algaze to enlarge four of his signature images and print limited editions in pt/pd/au. I printed 12 of each plus artist's proofs and printer's proofs. They are from the duplicating film mentioned.

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Craig · Apr 4, 2023

jeffreyg said:
You don't develop it to a positive what you get will be a negative.

I'm not understanding the process. If I contact print a negative onto the X Ray film, wouldn't I get a positive image unless I reversal processed it?

jeffreyg · Apr 4, 2023

No. you will get another negative it’s a duplicating film. No special treatment is needed. It’s like making a duplicate slide

jeffreyg · Apr 4, 2023

Not regular X-ray film. X-ray duplicating film.

jeffreyg · Apr 4, 2023

Check with your dentist he may have used it before digital X-rays. It’s like making a print but you get a negative from a negative since it’s a reversal film

ic-racer · Apr 4, 2023

The older I get the more I'd say to print them and then destroy them. That is, If I owned them, I don't see any "time in the future" that I'd get around to printing the internegatives. For all the trouble of making the internegatives, I'd just make prints now to be preserved.

GregY · Apr 4, 2023

ic-racer said:
The older I get the more I'd say to print them and then destroy them. That is, If I owned them, I don't see any "time in the future" that I'd get around to printing the internegatives. For all the trouble of making the internegatives, I'd just make prints now to be preserved.

Yes... Make prints now

ntenny · Apr 4, 2023

Thanks—I’ve ordered a box to experiment with and see how it goes. The positive/negative terminology is confusing because the subject is a negative, but as I understand it I’ll get a “positive” copy of the negative, i.e., another negative without an interpositive stage.

The film is described as “white light sensitive”, which isn’t very clear. Is it safelight-safe?

I will print the originals before disposing of them, but these are negatives with significant family history value and I don’t feel that I have the right to discard them for future generations.

-NT

jeffreyg · Apr 4, 2023

Sorry for the disjointed response I am out running errands If you’re duplicating and not enlarging you can use a contact printing frame and rig a 15W tungsten bulb to a timer to make your exposure. It sounds complicated but it’s almost like making a proof sheet

jeffreyg · Apr 4, 2023

Red safelight is okay

Doremus Scudder · Apr 4, 2023

Many people who work in platinum/palladium scan their negatives and make enlarged negatives. There are even curves and profiles available for tailoring the final negative to the process. I don't think drum scanning is needed to make an enlarged negative (say 11x14 from 4x5) that is more than adequate for contact printing. So, I'd think that anyone who works that way could make negatives for you fairly reasonably. If there's no one in Portland, I'd recommend O'Brien Imaging here in Eugene. Walt is a wizard. Google the business and give him a call.

Unless, of course, you really want to do darkroom work yourself for fun.

Best,

Doremus

DREW WILEY · Apr 4, 2023

No 2, double negative method, is fairly easy if you have a decent contact printing frame and a clean darkroom habits. I've done it numerous times with excellent results. A regular fine grained pan film like FP4 works well (avoid high contrast ortho litho films). Your first emulsion to emulsion contact - the interpositive - should be slightly overexposed and underdeveloped, so that the full scale of the original old negative is replicated and easily reproducible. Then this interpositive is used for an emulsion to emulsion contact of the duplicate negative, or alternately an enlarged duplicate, and developed a bit more for sake of a normal printable contrast range. The exact amount of resultant contrast and density is of course dependent on your specific intended printing medium.

For this I prefer a developer like HC-110 more than D76 with its saggy curve effect; but that's a relatively minor point.

ntenny · Apr 5, 2023

Thanks for all the information. I’ve got some duplicating film on the way, and I’ll give a call to O’Brien Imaging and see if they can offer an optical solution. Shipping the negatives out may not be an option (they have to ship as hazmat, which may or may not be feasible), but I could drive them down to Eugene easily enough.

If I get a chance I’ll explore the double-negative method too. I’d rather work with ortho film so I can use the safelight, I think.

-NT

DREW WILEY · Apr 5, 2023

Orthopan film should be distinguished from high contrast Ortho Litho, which can be quite a challenge in applications like this.

ntenny · Apr 5, 2023

DREW WILEY said:
Orthopan film should be distinguished from high contrast Ortho Litho, which can be quite a challenge in applications like this.

Agreed, they’re very different critters. I’ve got a box of Rollei Ortho 25 around that I can work with; IIRC it’s a fairly high-contrast film and I’ll need to develop accordingly—probably dilute HC-110 for a time to be determined.

-NT

DREW WILEY · Apr 5, 2023

You'll have to test for your own dev dilution; but if I recall correctly, I was using HC-110 1:15 from stock solution (not concentrate); and stock itself is 1:3 from concentrate.

jeffreyg · Apr 5, 2023

Just to summarize what I do with the x-ray duplicating film. If duplicating a negative and not enlarging : under a red safelight sandwich your negative (the original negative emulsion up and the dup film emulsion up because you will be turning the dup over when printing) with the duplicating film in a printing frame as you would be making a contact sheet, make a test as you would when making a print to determine the exposure time, develop, water stop and fix. You can use a tungsten light source for this. Once the exposure time is determined just repeat exposing the full sheet at that time. Develop, water stop, fix and wash and you are done. If you are enlarging the negative : do as you would be making a print. I suggest you might need to have the lens open to the widest aperture because the film is slow. Since it is a reversal film burning and dodging are the opposite ie burn if the final print needs a darker area or dodge if the final print will need a lighter area. The film has notches on the upper right corner to indicate the emulsion side like sheet film. Similar to slide film over exposure will give you a lighter slide and under exposure will give you a darker slide. This is a phone copy of of a pt/pd print from an enlarged neg from 120 Delta 400 on to x-ray dup film. Once you try a couple it won't sound confusing.

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ntenny · May 18, 2023

It took me a long time to get around to this, but I wanted to come back to this thread, report on my initial steps, and thank everyone for the guidance. I ordered a package of the dental duplication film--it came in 5x12, so I can trim one sheet down to a 5x7, a 4x5, and a small leftover strip.

My first trial negative is attached. The original (the cleaner and slightly lighter attachment) is a 5x7 taken by my great-grandfather sometime in the 1930s. I followed Jeffrey Glasser's suggestions above, working under a red safelight.

With the enlarger set up approximately as if making an 8x10 print from 35mm, and the lens at f/2.8, I exposed for a minute, then developed for four minutes in HC-110 dilution B; water stop, fix and rinse as usual. (The film has a blue base, and it's quite opaque until it hits the fixer, when it clears almost instantly--it's not so easy to develop by inspection, and I'm not confident I've got the ideal development time.)

The results are better than I expected the first time out. I seem to have a bit of a dust problem, and in one place I scratched the emulsion side, probably while cutting it down to size. To the naked eye the negatives look pretty close, but I'm not sure I've quite dialled in the same contrast; I haven't been able to get the shadows of the duplicate to match the original yet. Research continues.

Thanks to everyone; I had no idea this was feasible, and I'm still pretty blown away by a film that develops as a reversal in ordinary chemistry. I'm not sure--will extending development get me more contrast, or less?

-NT

RalphLambrecht · May 18, 2023

ntenny said:
I’ve inherited some family negatives on nitrate stock, 4x5 through 8x10. They’re in good condition, but I know I can’t rely on them to stay that way, and then there’s the fire danger, so I need to find a way to archive them in a stable and safe format.

I would like to end up with negatives, so I can print from them optically. This may not be practical to do for all the images (there are a few dozen on nitrate), so I may end up keeping scans of the ordinary ones and negatives of the best few.

As far as I can tell, I have three options for producing negatives:
1) pay for drum scans followed by a print-to-film process;
2) do my own darkroom work to contact print them to interpositives, then to duplicate negatives;
3) do my own darkroom work to contact print them into a direct-positive process.

Obviously #1 is the easiest, but it’s prohibitively expensive to use for more than a few sheets. I only found one lab that can do it (BowHaus in Los Angeles).

#3 looks hard. I’ve done a little b&w reversal before, found it fiddly, and never got really good results.

So I’m curious about #2. How hard is it, assuming I’m a competent but not exceptionally detail-oriented LF worker? Past threads have seemed not to have consensus on what film to use (my impression is either pictorial ortho or ortho litho, with film developer), and I don’t know where to start with exposure. I guess I’d like a brief practical guide to this process.

Also, are there any options I’m overlooking—again, assuming I want to end up with negatives?

Thanks
-NT

I've got something for you on the subject. Please send me a private email request to rwlambrec@gmail.com

jeffreyg · May 18, 2023

NT
You can make a test negative as you would for a print to see the amount of exposure. Remember the more exposure the lighter the negative and the darker the print. You can burn and dodge areas for desired.
I use the enlarged negatives for platinum/palladium printing and normal developing times have been good for contrast. If need be you can modify contrast when making the print from the negatives
As I had mentioned it takes a few tries to find your groove. Once you do you will like that technique. Your first attempt looks like you’re on your way.

Duplicating LF negatives

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