Duplicating a negative

I've researched everything in my local library, but haven't found much on duplicating a negative. I have a medium format 6x6 negative on Konica IR film that I very much want to make a copy of. Is my best bet:

[A] Making a contact negative, and then making another contact negative of the first? If so, what film would be best? The negative is fairly contrasty, as you might expect with IR film.

Doing the same thing, but enlarging it onto 4x5 film?

[C] Going to a professioanl and having either [A] or done? I typically use Modernage in NYC, but would love suggestions as to who might be best suited for this work in the city.

I wasn't sure which forum to put this in, but this seemed a better match than enlarging, darkroom or medium format.

You can take it to a lab like Modernage or Duggal, both of which are set up for this sort of thing, or I'd recommend copying it to 4x5". You can do it with a relatively neutral film like TMX or ortho film, so you can work with a red safelight. Generally, you tend to pick up contrast in this process, so it's best to make a relatively flat looking interpositive, controlling the contrast by development time.

If it's just a one time thing, have it done professionally. If it is going to be part of a new process for you (such as enlarging for an alternative process) then you might want to consider investing your time, effort and money to do the job yourself.

There are several ways to do this:

1. Make a dupe (it will be a positive) then dupe that to get a negative. You should use a low contrast process for this.

2. Make a direct dupe negative using a reversal (positive) process. Again, use a low contrast process.

Either of these will make a suitable dupe negative, as long as the overall final contrast is about 0.6. You can enlarge the original or decrease the size using an enlarger. I use my enlarger for 35mm originals and enlarge to 4x5. I do B&W and color.

3. (GAG-GASP) Scan the negative and then dupe it digitally to any size and contrast you wish. Since the original is analog and your final print (I hope) is analog this is not a mortal sin, only a venial sin. (IMHO) I do this when I want to make contact prints from 35mm or 4x5. I digitally enlarge to 8x10 and then contact print.

PE

A contact print will be best to keep the sharpness. From there, you need to decide whether to use an interpositive (option A), a reversal process (unlisted option), or letting someone else do it (option C). Since option C is always available, you might want to try to do it yourself just for the experience. If you can't make it work, you can always take it to someone else. In doing it yourself, the internegative gives you more control and may help keep the contrast down. But more control also means more chance for error, so you might want to try reversal processing. The amount of work is about the same for either.

Terence said:

I've researched everything in my local library, but haven't found much on duplicating a negative. I have a medium format 6x6 negative on Konica IR film that I very much want to make a copy of. Is my best bet:

[A] Making a contact negative, and then making another contact negative of the first? If so, what film would be best? The negative is fairly contrasty, as you might expect with IR film.

Doing the same thing, but enlarging it onto 4x5 film?

[C] Going to a professioanl and having either [A] or done? I typically use Modernage in NYC, but would love suggestions as to who might be best suited for this work in the city.

I wasn't sure which forum to put this in, but this seemed a better match than enlarging, darkroom or medium format.

Click to expand...

hi terence

kodak used to make a single step ( negative to negative ) duplicating film.
it was called so-132. photowarehouse used to sell it as well ( after kodak stopped making it ) and i have used it pretty often.

it is about the speed of azo and you expose it to a bright light. it is handled like photopaper, and processed in paper developer.
i have used it a bit i still some that i bought a few years ago for a project, you are welcome to it if you are interested - it is 4x5 in size.

the only drawback it that it isn't enlarging speed so you would not be able to make an enlarged negative ...

pm me if you are interested!

john

Thanks folks. I think I'll have the pro's do it first and then try my hand at it.

Are there any good reference resources out there for how to do this? I've played with ortho film as an in-camera film, but have never actually used it to copy work.

Also, what do people do for 120 film? I don't see much 120 ortho anymore. I guess I could use 4x5 and just accept the wasted area (the engineer in me hates that idea though). Cutting down sheet film doesn't seem to make much sense, as I still need to fit one of the film carriers for the enlarger.

nworth said:

A contact print will be best to keep the sharpness. From there, you need to decide whether to use an interpositive (option A), a reversal process (unlisted option), or letting someone else do it (option C). Since option C is always available, you might want to try to do it yourself just for the experience. If you can't make it work, you can always take it to someone else. In doing it yourself, the internegative gives you more control and may help keep the contrast down. But more control also means more chance for error, so you might want to try reversal processing. The amount of work is about the same for either.

Click to expand...

I list the "unlisted option" in my post above.

Enlarging the original, such as 35mm to 4x5 or 8x10 eliminates most of the sharpness problems by virtue of forming such a large intermediate. Digital enlargement does much the same.

PE

You could do as a few other people have suggested, and make an intermediate positive (a.k.a. an interpositive), from which you will make the final negative. This is the method which I used for years when I used to have to make a quantity of B&W prints from a colour negative. This will also work if your original is a B&W negative.

The first step was a flat, dark interpositive on a panchromatic film. I originally used Super-XX. When it was no longer available, I used T-Max 100.

The next step was an internegative, on Kodak Professional Copy Film, also no longer available. The reason for this film was that contrast was controlled by both development and exposure, it having a compound characteristic curve. You could try a normal panchromatic film, but you may have to develop it it a higher than normal contrast developer, like D-19. You will find that extending the times in a developer like D-76 or HC-110 won't give you the contrast you will need to get a decent negative.

Contact is the way to go, if possible. If you are making this duplicate negative because you want a large negative for contact printing or because you need a large negative for very large enlargements, then you should make the interpositive by contact, and the internegative by projection. The reason for this is that dust will be a major problem, and dust on the original negative will be white on the interpositive, and will ultimately be white on the final print, which is relatively easy to retouch. If you get dust on the interpositive, it will be black on the final print, which can be very difficult to retouch. If you make the internegative via projection, it is somewhat easier to keep clean than a contact internegative.

E-mail me if you want further details.