Negative curl

RPippin · Jan 7, 2009

I'm a bit new to developing my own film and have a couple of questions. I've made sure the temps and timing were correct, but my negatives seem to have a bit to much curl to them. Once they are cut and put in covers I can put something heavy on them and they will flatten out a bit. I don't have a glass negative holder for my enlarger for 6X6 and need them to be as flat as possible. Any suggestions? Thanks in advance.

Jon Shiu · Jan 7, 2009

Hello, what enlarger do you have? It would be best to get a glass negative holder. Also, for some negative holders, you can get a piece of Anti-Newton Ring glass, such as from a Gepe 6x7 slide mount, smooth the edges with sandpaper, and fasten the glass to the upper part of the negative carrier, inside to flatten the negative. Another idea is to make your own negative carrier out of two pieces of glass, hinged with tape. Watch out for Newton rings, though.

Jon

bobwysiwyg · Jan 7, 2009

Can someone explain Newton Rings to me, what causes them, what prevents them?

trexx · Jan 7, 2009

http://en.wikipedia.org/wiki/Newton's_rings

An issue with glass carriers that shows up sky and other uniform density parts of a scene.

TR

archphoto · Jan 7, 2009

The problem starts with drying the film after dev and fix: I use a cloth-line, bend paperclips to hang 35 and wooden clothpegs for 120 and weigh the films down at the bottom end. At least the neg's dry without a curl.

Konical · Jan 7, 2009

Good Afternoon,

The usual solutions are weighting the film as it dries, reverse winding it for a day or two, and putting it under something flat and heavy if it's already cut into segments. Curled film usually presents more problems in contacting than in enlarging where a good negative carrier will often do the trick. A fairly recent APUG thread on this topic has numerous entries; I suggest a Forum Search.

Konical

Klopstock · Jan 7, 2009

If you used polyester based films, choose a normal film on acetate base next time

During winter, in heated building causes very dry air. The gelatin shrinks and curls as it 'exhausts' water. Maybe a simple air humidifier will help. Quite simple: put a wet towel on the radiator (unless it is an electrical heater).

bobwysiwyg · Jan 7, 2009

trexx said:
http://en.wikipedia.org/wiki/Newton's_rings

An issue with glass carriers that shows up sky and other uniform density parts of a scene.

TR

Thanks for the link, very understandable though I don't think I will commit the formula to memory.

ntenny · Jan 7, 2009

Klopstock said:
If you used polyester based films, choose a normal film on acetate base next time

You say that as if all films were equal. Curly polyester is a pain in the donkey, to be sure, but you're gonna have to pry my CHS 25 from my cold dead fingers anyway.

Actually, I've lately been experiencing really annoying longitudinal curl with (the 35mm version of) that normal-est of normal films, Tri-X. I suppose if I were a clearer-headed thinker, I'd just stick to bigger formats, but some of those little 35mm cameras are just *so* delightful to use!

-NT

JRJacobs · Jan 8, 2009

Certain brands of film are just very curly by nature, where other ones dry very flat. Worst one I ever saw was Arista.EDU 200 in 120 format - curls into a tight little cylinder when dry (oddly enough, the 35mm version of this film does not do this). FP4+, on the other hand, dries very flat. If the curl bothers you with the film you are using, try a different version. Dealing with curly film can be frustrating in the darkroom.

Negative curl

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