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TSSPro
03-04-2010, 01:56 AM
Has this ever happened to you in the past?

Made several prints in the same batch of chemistry that I mixed up that day and they had faint little crescents on them. I inspected the negatives and found no crescents on the negs, and if I make an enlargement of the same image multiple times, the crescents arent in the same place every time. Nor are they in similar pattern on any of the other prints they showed up on.

These are 15 inch square enlargements on Ilford MG FB, from an Omega enlarger, using sprint chemistry. I was not using trays large enough for the paper so I was forced to "roll" my print constantly through the chemistry to get coverage of the whole sheet. Could the bending of the paper while it is rigid before it becomes saturated cause these crescents?

I'm just a little stumped and hoped some one might have some insight.

Thanks.

richard ide
03-04-2010, 02:47 AM
It sounds as if you have paper with kinks in it. Some papers are very sensitive to handling. Try to keep your sheets flat and handle more gently. You are not alone.

TSSPro
03-04-2010, 03:47 AM
Thanks, I'm picking up where I left off later today with re-printing my enlargements. I'll make sure to track down some larger trays.

Bob Carnie
03-04-2010, 09:24 AM
As Richard points out probably kinks, any touching of the back of the print during the wet stage will cause dimples and in extreme cases kinks.
Everyone starting with processing has this happen to them.

I do not use print tongs for this reason but wear gloves and hold and flip from the very ends. I always give genourous white space around the image .

Mike1234
03-04-2010, 01:42 PM
Stop eating French pastries in the darkroom and the crescents will go away.

stradibarrius
03-07-2010, 09:41 AM
I had this problem and realize there was a tiny hole on the lens plate where light was leaking through. A little black tape and everything was ok.

richard ide
03-07-2010, 10:07 AM
The OP said that they occured in different places on the prints which would rule out a light leak. This can happen when the emulsion is physically stressed in localized areas. Kodak manufactured a film which produced a halftone negative by physically applying a dot pattern to the surface which would trigger development beginning at each stress point. The size of the dot depended on the exposure to the gray scale range of the subject being photographed just as in a conventionally produced half tone negative.

Anscojohn
03-07-2010, 11:12 AM
Has this ever happened to you in the past?

Made several prints in the same batch of chemistry that I mixed up that day and they had faint little crescents on them. I inspected the negatives and found no crescents on the negs, and if I make an enlargement of the same image multiple times, the crescents arent in the same place every time. Nor are they in similar pattern on any of the other prints they showed up on.

These are 15 inch square enlargements on Ilford MG FB, from an Omega enlarger, using sprint chemistry. I was not using trays large enough for the paper so I was forced to "roll" my print constantly through the chemistry to get coverage of the whole sheet. Could the bending of the paper while it is rigid before it becomes saturated cause these crescents?

I'm just a little stumped and hoped some one might have some insight.

Thanks.

********
Some times marks from overzealous use of print tongs look like crescents.