Using an enlarger to make an 8x10 or 16x20 negative for contact printing from 4x5

[Steven Ruttenberg]

I have heard something of this, but is there a good tutorial on how to do this? I would assume it involves making a positive of the negative and then a negative of that image at the size you want. This would be better than trying to figure out digital negatives, but I will eventually try that too.

[Pere Casals]

https://unblinkingeye.com/Articles/E...nlargeneg.html

It is also covered in the Chapter 13 of The Darkromm Cookbook https://silveronplastic.files.wordpr...er-2008-ww.pdf

[ic-racer]

http://www.ultrafineonline.com/ulcotodufi.html

Ultrafine Continuous Tone Duplicating Film

Ultrafine Continuous Tone Duplicating Film *** SPECIAL ORDERS ONLY ***

Make duplicate B & W negatives or slides. Enlarge or contact. Blue Tint .007 mil polyester base. Slow speed ( ISO 4) Standard development in either photo paper developer or Graphic Arts Rapid Access. Yields direct positive image. Red or Yellow safelight. Compare to Bergger BPFB18 and other similar films.

[Bob Salomon]

I have heard something of this, but is there a good tutorial on how to do this? I would assume it involves making a positive of the negative and then a negative of that image at the size you want. This would be better than trying to figure out digital negatives, but I will eventually try that too.

I’ll bite, why not just enlarge directly to paper?

[ic-racer]

I’ll bite, why not just enlarge directly to paper?

I think others do it because of the need for a UV source for some printing processes. Even just to try "Azo" paper in 8x10 size.

[Steven Ruttenberg]

I am thinking of making up to 16x20 platinum contact prints is why I am interested.

[koraks]

I'm tempted to try this with xray film one day...when I find the time. It should be just about perfect for this task.

[Jac@stafford.net]

When we make an optical enlargement, accutance is diminished, but that is not always a bad or significant factor.
Try, enjoy.

[interneg]

It's not spectacularly technically difficult. Main thing is avoiding dust & whether you take a single step (reversal process of positive to make enlarged neg) or two step - contact positive, then enlarged negative. Register masking may become a fact of life depending on the specific contrast range you want the final negative to comply with. You might want to work extensively enlarging to 8x10 before spending serious money on 16x20 film. A BW transparency (run in something like the Scala process) may also be a good starting point depending on your processes/ tastes etc.

[Tin Can]

I have used X-Ray for interpositive.

It's a 3-1 macro on 5x7 FP4 then contact printed to cutdown 4X5 X-Ray and then enlarged to 11X14 negative print.

You all may have seen this before as I have posted it. Initial neg had too much empty space and I didn't like the positive print.

Atomic Bomb by TIN CAN COLLEGE, on Flickr