Help: How to convert a negative to positive to print as a "negative print"

[robert taylor]

Hello all. I need your help. After 40 years of "regular" printing, I finally have need to print a subject as a negative, as Paul Caponigro and others have done. I have a friend with a large ranch on which a giant Valley Oak stands. She wanted a photograph of it, but after seeing the negative, wants a matching photograph of the negative; a negative print. We all know how beautiful 8x10 negatives can look in and of themselves and I must confess that this negative, with the tree delineated against a foggy background, would make an interesting match. Understand that I am not going to do this digitally so I need another old geezer's advice who has done this successfully the traditional way in the darkroom. In general terms I am assuming I would sandwich the original 8x10 negative atop a piece of 8x10 film (hopefully another sheet of the same, HP5+), emulsion to emulsion, on a black sheet of paper with a piece of glass (ANR?) on top to hold everything flat. Then, positioned under the enlarger, I would expose and develop the same way I developed the negative. Am I right or wrong with this? Also, what ball park help can you provide about f stops and exposure times under the enlarger? I am thinking I would cut up a piece of film and test for exposure times...but what do you folks who have done this advise to help me with the learning curve? Any details you remember would be greatly appreciated. Thank you very much in advance for any help you can provide!! Robert

[xkaes]

You've got it all right. I have not done it in years. Just place the new film on the bottom and the film with the image on top -- emulsion to emulsion. CLEAN glass on top. The bottom is best a BLACK material. Exposure depends on the film and amount of light, but a good start would be an incident meter on the top. The films do not need to be the same type.

A good approach would be to make a test strip of the first exposure. Let's say the meter says 30 seconds. Make strips of 10, 20, 30, etc. to 120 seconds. Contrast can be varied with development, etc. to make a good match.

Then with the positive negative make a negative print! With VC paper under an enlarger you can vary the contrast to suit -- assuming B&W. For some "scenes" reversing works out great.

Tons of fun. Brings back memories! I'm working on a small print from 1941 that I have to turn into a decent negative for enlargements!

[Bill Burk]

If you make the inter-positive emulsion to emulsion you will have to print base to emulsion. So think that part through.

You will want to develop longer than usual to get a 1:1 tone relationship. Exposure will not be critical since you will be able to adjust final exposure on the print.

[Tin Can]

It's pretty easy. He's one from 5X7 original neg to 4X5 inter neg enlarged to 11x14. I had too much empty space on the 5X7 original.

http://www.largeformatphotography.info/forum/showthread.php?120079-Post-Your-Photos-Made-At-Close-Distance&p=1419896&viewfull=1#post1419896

[robert taylor]

XKAES, Thank you very much for the information and your time. I wish you the best with your 1941 print/negative project. The ones I've done like that were tricky not only due to the number of defects on the original print but also due to the defects of the photographer; e.g. my mother, who always seemed to have a case of the "wobblies" behind the camera. Take it easy, and thanks again! Robert

[robert taylor]

Bill, Thanks for the heads-up that I would end up printing with an inter-positive that would need to be placed emulsion side up in the negative carrier (I think that's what you've warned me of). I've never actually done that except by accidentally reversing a contact print when proofing. Hopefully that doesn't create a problem regarding sharpness or anything (?). Thanks again!

[robert taylor]

Thank you, Randy. It was nice to see the example image you provided--quite a nice one! Robert

[photonsoup]

I've made lots of contact prints from paper negatives so I see no reason that a "contact negative" from a print wouldn't work out. As long as the print doesn't have something on the back, Kodak paper would defiantly not work!

[koraks]

The internegative route is one option, one that is a bit more chemically involved is a direct reversal print: expose a print through the negative, develop the print, then bleach it in a non-rehalogenating bleach, then fog (chemically or optically) and develop again. With VC paper, I think the internegative route is quicker to dial into the right contrast though.

[pau3]

If you only want a negative image on paper there is a simpler solution. Just contact
copy a nice positive copy - that is, one with full tonal range - on the paper you want.
Develope it as usual or, to control contrast, you can combine two developers,
HC110 at 1+100 and Dektol or Eukobrom, usual dilution, just remember to stop
with water between developers. I use this last approach. Depending on the paper
you're using, its threads may be visible. It is also a way to obtain enlarged negatives
on paper. If necessary, the paper can be treated later to make it less opaque.

One of the advantatges of this approach is that you can work with normal safelight
conditions. Another, from my point of view, is that increases the ways to manipulate
the image: you can use the new negative to produce new positives...

[MartinP]

Make a lowish contrast, but dodged and burned, paper (RC glossy) print having the eventual size required - but make it with the neg 'upside-down'. Use the wrong-way-round paper inter-positive to make a contact-print on non-textured paper as the final result. Much quicker, cheaper and simpler than using ortho-film and so on when that isn't really essential for the final result (ie. no masking needed).

[Drew Wiley]

I prefer FP4 for this kind of work. But you'll need to waste a sheet of film first as a test strip relative to exposure time. A good contact printing frame helps. If you have to flip the final interpositive in your enlarger easel, no problem. Sheet film will still look sharp.

[Drew Wiley]

Oops - what I just said might be misinterpreted. You expose the negs emulsion to emulsion, but then if necessary correct the orientation by flipping it in the enlarger neg carrier (not easel).

[Pere Casals]

Hello all. I need your help. After 40 years of "regular" printing, I finally have need to print a subject as a negative, as Paul Caponigro and others have done.

You can simply perform a reversal development with paper in the same way BW slides are obtained.

This is expose and develop, stop bath, bleach to remove metallic silver, open lights to expose remaining silver halide, develop again (until completion if well adjusted, or less), stop bath again and fix.

You can use an stouffer density wedge to calibrate the process with different paper contrast grades, so you can nail a result at the first time, as reversal development is longer it is nice to have the thing calibrated

https://www.photrio.com/forum/threads/reversal-processing-of-black-white-paper.44354/

It is also performed if using paper as a "negative" but wanting a positive image in the paper:

https://www.youtube.com/watch?v=50YgsRDYjL0

If you use dichromate remember contact has to be avoided. For disposing mix it with used developer, liquid will change from orange to dark green, being a way more safe stuff.

[Tin Can]

Not so simple and the bleach is bad news. I have done reversal ULF film.

An FP4 interneg as I have used and Drew recommended is way faster and cleaner.

If a print is the desired outcome. Which it is in this case.




You can simply perform a reversal development with paper in the same way BW slides are obtained.

This is expose and develop, stop bath, bleach to remove metallic silver, open lights to expose remaining silver halide, develop again (until completion if well adjusted, or less), stop bath again and fix.

You can use an stouffer density wedge to calibrate the process with different paper contrast grades, so you can nail a result at the first time, as reversal development is longer it is nice to have the thing calibrated

https://www.photrio.com/forum/threads/reversal-processing-of-black-white-paper.44354/

It is also performed if using paper as a "negative" but wanting a positive image in the paper:

https://www.youtube.com/watch?v=50YgsRDYjL0

If you use dichromate remember contact has to be avoided. For disposing mix it with used developer, liquid will change from orange to dark green, being a way more safe stuff.

[Nodda Duma]

Take a photo of the negative on a lightbox and enlarge that. Or strip test when you do a contact "print" onto a negative. Print paper is roughly ISO five or so, so your exposure time will be reduced by the ratio of your film speed to paper speed (20x for ISO 100 film)

[Tin Can]

Take a photo of the negative on a lightbox and enlarge that

That's an inter neg!

[Nodda Duma]

That's an inter neg!

What is that cheating? :)

[Tin Can]

What is that cheating? :)

No of course not. But it's still an inter neg. I think reversal has an issue with the bleach.

Why use poison when there are cleaner methods?

[koraks]

No of course not. But it's still an inter neg. I think reversal has an issue with the bleach.

Why use poison when there are cleaner methods?

Then do it in photoshop, no poison involved! (In your house at least ;))

[Tin Can]

I consider computers, printers and their ilk to be very poisonous to our planet. Yet I do own and use it all. OE Sin. Not the OA.
Did you guys read the OP question?

[koraks]

Yes, I read it. I would personally try both the internegative route and the reversal route. They both have their pros and cons.

[Tin Can]

Yes, I read it. I would personally try both the internegative route and the reversal route. They both have their pros and cons.

Fair enough. I will be doing reversal when I personly want a slide, maybe even a glass Lantern slide. Old time Lantern Projectors fascinate me and I am sure as a child I saw them, but I forget...

[Pere Casals]

the internegative route and the reversal route. They both have their pros and cons.

Yes, I agree... the interpositive (in fact it's an interpositive, as it's a positive intermediate) has the advantage that it uses common chem and skills.

The reversal saves a film sheet and it's processing, but requires new chem, the dichromate bleach has special handling because safety, instead the permanganate bleach is safe but more prone to problems... and the reversal processing requires a good calibration to save time.

I first thought in the reversal process, nothing wrong with it, but IMHO it is more practical the interpositive, in the way Drew explained well. If we are to make several test prints to nail a result then the complex reversal process will take much more accumulated, so making the interpositive it's worth.

Also to consider that the reversal process is more difficult to adjust and perhaps we may need some Farmer's reducer bath or local application to clean whites...

[Chuck Pere]

If you are using glass carriers printing base side down can give you more Newton's rings problems. I've had the problem printing flipped negatives. The last time I tried negative images I was using Kodak Commercial 6127 film. Used under a safelight and slow.

[Drew Wiley]

I use AN glass top and bottom. It does not affect sharpness, and the texture rarely shows unless you're using a very hard paper grade.