Using enlarger to make internegative? : LUSENET : Large format photography : One Thread

I have quite a few old 35mm negatives I'd like to convert to 4X5 and am wondering if I could use my enlarger to project the enlarged 35mm image directly onto 4X5 TMAX and reverse process by way of Kodak's TMAX Reversal Kit. One of the advantages of this would be that a couple of the 35mm negatives have slight imperfections which cold light enlargement would help minimize.

Has anyone tried this? How would you meter the projected image? I'm prepared to bracket like crazy, but would like to start off in the general ballpark. Any suggestions, ideas, or warnings welcome.



-- Michael Veit (, September 30, 2001


I tried to make my own 35mm to 4x5" (using an enlarger) and 35mm to 6x7cm (using a view camera/roll film back) internegatives (not positives like you want) with T-MAX 100. The results were dismal. Very soft for some reason, even with a macro lens on the view camera. After checking with my lab they had similar problems and went to using Super XX, which is now defunct I believe. The lab was stocking up and freezing a lot of this film for this purpose. That was a few years ago and I'm not sure what they use now. Why not use Scala or Scalia film which is a direct positive film? It may only be available in 35mm.

-- Richard Stum (, September 30, 2001.

Cut a piece of white paper the size of you film holder, put it into the holder, place the holder under the enlarger and adjust the projected image on the paper for size and focus, tape the film holder to the base board, set the apeture to F/22 and the timer for 1/2 second burst,turn off all lights and replace the paper in the film holder with Tri-x, using a piece of mount board or thick cardboard, make 1/2 second exposures, moving the cardboard down 1/2 to 1 inch each time depending on the number of exposures you want on the sheet of film, develope in Pyro (PMK) and find the strip with the contrast you desire, if it is not there, put in another sheet of film and open the apeture one stop (f/16) and try again, you should not have to use more than 2 sheets of film, you can also increase the exposure time to 1 second if you wish or do both together. Pat

-- pat krentz (, September 30, 2001.

If i read your question correctly, you're not talking about an "interneg" as much as a "duplicate negative" or an "enlarged neg" which case, you don't have to use a reversal kit...

There are 2 ways to do this, one is with a direct positive dupe film like Kodak's SO-132. This is an ortho dupe film that's pretty slow, about the speed of Azo. In fact you can use Azo to proof to exposures.You can develop it to a variety of CI's in either a paper developer like Dektol, or LPD, or in a developer like XTOL, DK50 etc. I use this film to make contact dupes of old nitrate negs, and use DK50 in a tank.

SO-132 was going to be discontinued, however it seems that it will be made for another year or's an expensive film, running about $40 or so for a 25 sheet box of 4x5. But you can dupe a neg in one step...

The next method is the preferred choice for control in duping do it in 2 steps, making an enlarged interpositive, then contacting this to another sheet of film, for a negative. There is an Agfa Duplicating film, P330p that's a good choice for this, but that too is pretty expensive & hard to get. The next choices are Delta 100, and Plus-X for the interpos. The duplicate negative is usually made on an ortho film like Kodak's (discontinued as well) Commercial Film, or Ilford's Ortho Plus.

When you make the interpositive, it needs to be denser than what a good print would look's not meant for viewing. The dupe neg needs to be a little dense as well, to have enough information in the shadows. (if you're into sensitometry, aim for a dmax of 2.5 for the interpos, and a Dmin of .50 for the negative)

If you make contact dupes, do them emulsion to emulsion. lastly, if you use SO-132, make sure you follow kodak's processing recommendations. The earlier versions of this film had pretty lousy storage the processsing steps are critical, and include NOT using a hypo clear, rahter going for a full wash...and for permanence, using a toning step of selenium or brown toner. what else (sorry for the disjointed answer...too early...)?? the 2 step method is preferred because it will give you control over the final output, if you approach the interpos like you were making a print. With a panchromatic film, you can use filters to take out stains in old negs, and you can do dodging & burning, etc. SO-132 is a funky film to use, and the contrast range of the material can be a lousy match for certain types of negatives. The 2 step is used by most archives for neg duping, because the interpositive becomes the "master" and all the dupe negs become "working negs"....the only book on all this, readily available, is Kodak's "copying and Duplicating in B&W and Color"...hope this helps, and feel free to drop me an email if you need more info.

-- DK Thompson (, October 01, 2001.

Oh yeah, one other thought...Super-XX was one film that Kodak used to recommend for 2 step duping. Now, they'll tell you use tech pan for the interpos, developed in HC-110 (B, i think)...with TMAX 100 as the dupe neg. Bergger makes some ortho type dupe films as well, that are sorta like the Agfa ones. I don't think they have a direct positive film, but they do have one similar to the negative acting film. If you're using an enlarger to project your 35mm negs, mask out all the stray light, and use a black background (construction paper will do) on your easel to hold the film (emulsion up of course). You can use a film holder for this too. It may be a little easier to use an ortho film, like Ortho + for both the interpos and the neg, but most prefer to use a pan film, then an ortho. With all ortho, you could do both steps under a red safelight....BTW, I use ortho plus as well, and run it in TMAX RS (tank) for normal contrast, and LPD 1:4 (tray) for higher contrast. Good luck....

-- DK Thompson (, October 01, 2001.

ha...if that wasn't confusing enough, I thought of one more tidbit....usually when you dupe by contact (emulsion:emulsion), the dupe neg now becomes, you need to make a little note of this someplace, either on the sleeve/envelope or by cutting a "new" notch code. You then flop the neg in the carrier to make a right-reading print. It becomes very easy to lose this over time & I find myself trying to figure out which way is "right" alot with old dupe, make a note early on.

-- DK Thompson (, October 01, 2001.

Wow, thanks to all for their responses!

DK, I have some Plus-x for the interpositives, but can't find any 4X5 Ilford Ortho listed at either B&H or Adorama. Would quality be seriously diminished if I used Plus-x or the like for the dupe?

-- Michael Veit (, October 01, 2001.

No problem....if I had thought more about it, I could have condensed all that a for Plus-X, yeah you can use the same type of film for both steps. If that's what you have, try that may be a little tricky dealing with sandwiching 2 same sized negs together in the dark, but I think if you practiced a bit you could do it. Especially going from a full framed 35mm image, you might have a little "slop" around the image area. One more thing is that if you need to alter the contrast (push/pull), you would do this in the neg duping part. Not the interpos. If your aim is for a grade 2 print, then you can control the contrast of the dupe neg to get to this....either by overexposing & underdeveloping to cut contrast, or doing the opposite to add...You control the density more in the interpos. step, and use the original neg as your guide. If you have a bunch of negs that are of different densities & contrasts, try grouping them in, you can work on similar ones at the same time. This will help you standardize on at least part of the exposures & developing. If you take notes & pay attention to what you're doing, you'll get the hang of it quickly, it's really pretty easy, the most confusing part is going through the whole neg-pos-neg ritual and keeping everything straight. Good luck, and you can get Ortho Plus from Calumet, I'll bet B&H has it, although it may not be listed....

-- DK Thompson (, October 01, 2001.

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