Its a mirror lens. I've yet to see a snappy aperture on a mirror lens.
SNIP
It sounds like
something to try. I suspect a large lens cap with a large hole cut in it
could give a one stop aperture to make up for focusing errors. More
things to try...
-jeff
The usual method would be to use ND filters on the rear filter mount
as anything reducing the front element would cause problems - a hole
in a cap would cause vignetting and increase the proportional impact
of the secondary mirror reducing contrast, etc. Sticking a larger
disc on the secondary mirror at the front would reduce the light
coming in and would be more effective, but again would probably
degrade the image significantly. I suspect that the best of these odd
options would be to make a series of Waterhouse stops - filter ring
for the rear mount with a set of different size hole masks as was
done before the invention of iris variable apertures. This is
probably not the best position for placing fixed aperture
restrictions but a cheap and simple DIY project if you've got the
time and inclination and it's much easier to cut small, precise holes
with clean edges.
AndrewF
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|