Having used ultrasonic cleaning equipment for a number of years, I can say
with some authority that I'd be reluctant to try this. The ultrasonic
cleaners of the commercial variety (e.g. watch & jewelry cleaning) are
powerful enough to actually etch the surface of softer metals, such as
brass. The cleaner's action would be most focused on the "pointy bits" of
the screen (such as the split-image & microprism edges), which is precisely
what you don't want. I haven't tried this on plastic, but I'd want to dunk
a piece of, say, Plexiglas into the cleaner for awhile (as in ten minutes)
and see what the results are.
The dime-store variety of cleaners (which are actually just plastic tanks
with mechanical vibrators) aren't nearly this powerful and so wouldn't
cause this effect, of course.
Regards,
Mahlon
------------------------------
Date: Tue, 19 Jan 1999 20:38:12 +0100
From: Lars Haven <lhaven@xxxxxxxxxxxx>
Subject: Re: [OM] Black specks on Focusing screen
It jut hit me: A way to clean these delicate focusing screens would be
by immersion in an ultrasound bath. Opticians use such baths to clean
normal eyeglasses, so the local optician can probably also handle a
focusing screen.
Fair warning: I've never tried it.
Regards
Lars
< 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 >
|