edges of negatives are blurred

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I developed two rolls of film (Both Kodak-400 speed). The edges of the negatives on one roll were blurred, all the frames were VERY DENSE. On the other roll, the edges were sharp and the negatives looked great. Development time was normal. Stop bath, fixer, etc were standard. Can anyone explain this?

-- David Jones (deajones@isaac.net), February 24, 2000

Answers

I assume that you are indeed talking about blur occurring in the negatives rather than in the print (this could happen as a consequence of negative popping). Considering your statement that the negatives were very dense, I think the blur might be due to halation. As you state that you didn't modify the development, the whole film is probably badly overexposed.

Although this is only conjecture, it sounds plausible that this might be a consequence of a slow diaphragma. If the diaphragma has not closed to the intended aperture (as a consequence of, e.g. dust or an aged lubricant), the shutter opens while the aperture is still too big. This might lead to overexposure.

This would be ruled out, if more than one lens was used for the negatives in question and they are all equally overexposed. (It is not very likely that all lenses fail at the same time.) If you used only one lens, detach the lens, actuate the diaphragma lever on the lens manually, and watch the diaphragma. If it closes in slow motion, it must be cleaned.

-- Thomas Wollstein (thomas_wollstein@web.de), February 25, 2000.


The dense roll sounds like it was drastically overexposed -- probably the result of a wrong light meter setting since the other roll sounds like it is fine. The blurring is halation, where the light has spread through the film base and fogged. A little halation can cause specular highlights to take on a sort of glow that makes an interesting effect, but generally it is avoided if possible by proper exposure and development.

-- Tony Brent (ajbrent@mich.com), February 29, 2000.

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