At 07:49 PM 2/20/01 +0000, Jeremy Zobel wrote:
I just received a bunch of lenses from a large purchase. I noticed oil on
the diapragm elements of the 50mm macro and tiny dust particles inside.
How does this effect the lens? Should I be concerned?
The oil on the aperture blades may cause them to "hesitate" when stopping
down. They should probably be cleaned.
The dust particles are unavoidable in any lens which has an open
construction (i.e., the barrel length changes when focus changes, which
sucks air into or blows air out of the interior of the lens). In general,
this is not a problem, because the dust particles cannot resolve, and you
will not notice them in your viewfinder or on the rendered image.
However, if there's a fair amount of dust, it *could* cause an increase in
flare (most likely manifesting itself as haze or a loss of contrast in your
photos). Only inspection of actual photos will help you determine whether
you like how the images are being rendered, and only a comparison with a
relatively "clean" example of the lens can tell you whether or not there's
unacceptable loss of contrast.
Garth
"A bad day doing photography is better
than a good day doing just about
anything else."
The Unofficial Olympus Web Photo Gallery at:
http://www.taiga.ca/~gallery/
< 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 >
|