light density ot the edge of 8X10 Negs

[michael_notar1]

developer runs along the edges of the film more frequently and therefore develops the edges

more. check your developing, you usually have to do constant agitation to get uniform dev.

[chrisb]

Hello all,

 

Recently I have been doing a fair amount of contact printing with 8x10 negs,

using a Sinar F2 and Sinaron-S 360 lens with new and qualified film holders only

to discover a increase in density in the last 1/64 of an inch on the neg

borders. The density appears to be fairly uniform and repeatable between film

holders over a wide range of apertures. The film holders exhibit no light leaks

symptoms, no edge fog, and in particular if I use the same setup, camera, film

holder, but use a Sinaron-S 210 the edge density is not visible. I am at a

loss, sure I could burn the edges of the contact for 3-4 minutes to correct the

problem, but what is the underlying cause?

 

Best Regards, Christopher...

[bruce_watson1]

That can also be caused by reflections from the flanges of the film holder that the film slides under. Some film holders need some light sanding of those edges to dull that sheen.

[big toys are better]

Both Michael and Bruce may be correct here. The issues with reflections will be more noticeable with wide angle lenses since the angle of light hitting the film will be more off axis. If this is your primary problem then there should be a discernible difference between using a 120-- 165mm lens and a 360mm or greater length lens, and the difference in density should also follow changes in local film density since there would be more light being reflected where more light hit the film. If development is a problem, try using good agitation in the very beginning and then less. A very good way to test this is to use Rodinal at 1:100 or 1:200 with stand agitation (no agitation after the first minute). If the line disappears, then your development agitation was the problem.