Creating larger negatives for contact printing.

[guitstik]

I am at an impasse here as to how to go about creating a larger negative for contact printing from a smaller negative such as a 35mm or MF negs.

I am wanting to do larger prints in the range of 30x36 in Pt/Pl and gum bichromate but the negs I have are to small and I don't have access to LF or ULF cameras yet.

The ideas that I have at this point are to use an enlarger to flash a larger negative to a positive from a 35mm or 6x7 and then flash that to another larger negative to form a negative in the size that I want to work with. I have tried looking for printers in my area that can create a large transparency negative but to no avail.

Any ideas how I can go about this?

[Photo Engineer]

I use my enlarger to go directly from 35mm to about 4x5 (considering the mismatch in aspect ratios). It gives me about a 3" x 4.5" negative. I use either color or B&W. I usually start with a 35mm slide though.

OTOH, I also can go directly to a digital negative of any size, but that is a topic for the hybrid site. So, no more on that.

PE

[holmburgers]

I'm curious about the same thing too..

PE, is the quality good, and is it easy/repeatable? How do you judge exposure to minimize wasting film. I don't have any dedicated enlarging meter, so what's the best bet?

[bblhed]

I use my enlarger to go directly from 35mm to about 4x5 (considering the mismatch in aspect ratios). It gives me about a 3" x 4.5" negative. I use either color or B&W. I usually start with a 35mm slide though.

OTOH, I also can go directly to a digital negative of any size, but that is a topic for the hybrid site. So, no more on that.

PE

Ok, I have wondered about 1000 times if it was possible to do that, and I just have to know, how do you get the exposure right to do that?

Look, someone opened a can of worms.

[guitstik]

So, I am on the right track then by creating a 4x5 positive on emulsion from a 35mm and then creating a larger negative from the 4x5 positive with the enlarger. That takes into consideration that I will have resolution loss from the enlargement of a smaller medium but I plan on doing some touch up to clean any problems that may arise. I appreciate the quick response PE.

[jerry lebens]

How about using Ilford's RC reversal paper to make a contact negative? Or using normal RC paper to make a positive, then contact printing that?

Regards
Jerry

[Peter Schrager]

xray dupe film comes in all sizes...try it you'll lkie it!!
Best, Peter

[Bob Carnie]

contact the negative rather than enlarge twice, will give sharper results.
remember when making the larger neg the exposure will be super super fast which will limit your creative input into the enlarged neg via dodging and burning.

So, I am on the right track then by creating a 4x5 positive on emulsion from a 35mm and then creating a larger negative from the 4x5 positive with the enlarger. That takes into consideration that I will have resolution loss from the enlargement of a smaller medium but I plan on doing some touch up to clean any problems that may arise. I appreciate the quick response PE.

[holmburgers]

Actually, if your goal is a large negative, I think that making an 8x10 print and then, as was suggested above, contact printing the paper onto 8x10 sheet film is a great idea. This way, you've got built in ND, the paper, and if the prints are consistent, the overall density range of a print will be confined to a much smaller range than a negative, and at a given enlarger height you'll always have the same exposure (save for some minute adjustments).

[David William White]

I've done this quite a bit, for contact printing (cyano mostly), also to 'fix' weak contrast or to clear up any compositional issues.

I normally use ortho litho film in 'film strength' soft developer. Arista Premium Halftone Supreme is really cheap, and much finer grain than your original negative. Exposure latitude of ortho litho is fairly forgiving, the speed is close to paper, and the first internegative (interpositive?) you can analyse on the lightbox. Exposure is pegged just like you would with paper i.e. test strips. I'll usually test strip one sheet of APHS and analyse as the positive on the lightbox, then I'm set.

Ortho Litho is available in many sizes from both Freestyle and from Ultrafine Online.