View Full Version : Help with Neg defect

John Jarosz
6-Dec-2015, 10:26
I need some help deciding what happened on two 8x20 B&W negatives. I made two exposures, one right after the other, which I only do occasionally when I feel I need a back-up neg. Film is Efke 100 developed in HC-110 dilution B. I have made comparative jpg's of the neg and a positive image of one of the defects along with another showing a scale just to emphasize that this is a relatively large defect on the 8x20 neg. The defect is in different positions on the two negatives. There was no such feature in the sky. I have never seen this type of defect in any of my negs and I'm using the same lens I have always used. The sun was behind me. I don't believe it's a reflection because the negative is less dense in the defect area. Could this be an emulsion defect? Developing defect? I saw it immediately while it was still in the fixer. I'm interested in hearing some thoughts. Thanks very much.

6-Dec-2015, 10:46
Were they particularly long exposures?

John Jarosz
6-Dec-2015, 11:11
No. 1/30 or 1/10 I forget

Gary Beasley
6-Dec-2015, 15:24
Looks like an airbell, a bubble stuck to the neg during development. That or a dust bunny floating around in the camera.

John Jarosz
6-Dec-2015, 15:57
I believe the dust bunny more than the air bell but not by much. I'd believe the airbell if there was only one, the negatives were developed separately. It seems way too co-incidental for it to happen on sequential negatives and in almost the same place.

But if it WERE an airbell (which I've never had before), would a wetting agent in the developer help prevent them?

6-Dec-2015, 16:15
Less density therefore either less exposure or less development one would think. Many years go had the same thing happen to me (in the sky area) on 8x10 film. "Fogged" another sheet from the box under the enlarger. Several same defects appeared on that negative. Re-examined the initial negative and found several more defects in other areas of the image. Turned out to be defective film. Tested several more sheets from the box and all had similar defects on them. Had to throw away whole box of film.

Stephen Thomason
6-Dec-2015, 16:20
Perhaps a drop of Edwal LFN in the developer. Although I have not yet experienced airbells, I recall several posts that did and the LFN was recommended. I bought some and plan to switch to it when my other is used up.

John Jarosz
7-Dec-2015, 07:13
"Fogged" another sheet from the box under the enlarger.

Not a bad idea.

My reluctance to accept airbells as the cause is fueled mainly by the size. I would think something that large would have to float off. Airbells from my 6x6 days were tiny.

Jim Jones
7-Dec-2015, 09:18
I've never added a wetting agent to developer, but routinely use it in a prewash with tray development. This was absolutely necessary when processing Tech Pan in Solarol developer.

Bob Salomon
7-Dec-2015, 09:41
What did you do to dislodge air bells while you are processing your film? Or don't you do anything to dislodge them?

John Jarosz
7-Dec-2015, 14:56
8x10 and 8x20 are developed one-at-a-time emulsion up in an open tray. I've never had a problem with airbells. I really don't want to estimate how many I've done that way because I don't want to think about how much money that adds up to. :-o

Bob Salomon
7-Dec-2015, 15:09
Seeing how many there are in the bottom sky area I would go with air bells.

7-Dec-2015, 18:34
Visitors from the planet ZORG.

John Jarosz
7-Dec-2015, 18:44
If it happened on a Carbon Print I would believe you. :D

But it's on the negative. :(