Originally posted by Ben_Edict Test charts are not well suited for testing vignetting, as the vignetting changes with focus distance
to place a peice of tracing paper on the film rails
Ben,
thanks for the suggestion.
I actually already tried the laterna magica method which has the advantage to deliver image circles in excess of 43mm.
For the 60-250, I however failed to take an exact measurement because I didn't construct a black box. It was around 40mm. Without a black box, the projected image at f/4 isn't that brighter than ambient light
I tried the tracing paper method but my camera either refused to trigger with an open door or didn't go to bulb with aperture in "A". So, I saw the image for a fraction of a second only. No vignetting at 60mm, a bit less sure at 135 and 250mm though.
You're correct with the focus distance dependency. At 250mm and 5m distance, the effect should be 250mm/5000mm = 5% or smaller though. Which is 1mm in the extreme corners.
I'll think about it again when I have scanned test shots