Archived posting to the Leica Users Group, 2000/02/20

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: RE: [Leica] Vignetting
From: Austin Franklin <austin@darkroom.com>
Date: Sun, 20 Feb 2000 10:46:03 -0500

This makes no sense to me.  The fact is, the emulsion of the film is on the 
exact same plane, no matter how thick the film is, and ALL light that hits 
the film MUST go through that plane.  Given that, it makes no sense that 
film thickness can have ANY effect at all on the phenomenon you are seeing.

It sounds like it could possibly be an aperture issue, not a film thickness 
issue.  Unless you do your tests with the exact same camera settings, I 
don't believe that test is very conclusive.

Please correct me if I am wrong.


- ----------

>Not really, although I could surmise based on simple geometry. But it
>does seems to matter. Very thin-emulsion films show vignetting much more
>clearly. If you don't believe it, take a lens known to vignette and
>shoot the same scene on Ilford 100 Delta and Tri-X. The Delta will show
>more vignetting. In fact, I usually run a roll of 100 Delta as my
>stardard test for vignetting when I try out a lens.
>