I would agree with Craig on this. Whether it is a filter or a dichroic
mirror, "soft-coated" or "hard-coated" filter, the preferred method is first
with compressed dry air and perhaps a soft lense cloth. If that fails to
remove the smudge(s) a small amount of MeOH, EtOH, or even Acetone will not
affect the coating if it is not repeated a multitude of times. Remember,
"soft-coated" filters are not exposed coatings, so there is either just
glass on the filter surface, or an AR coating. "Hard-coated" filters many
times are exposed but are more resistant to solvent attack. At least by the
ones mentioned here.
Water cleaning can also damage filters and as water does not evaporate as
quickly as the organics, if any gets behind the filter ring it will hang
around longer.
However, some grime does come off better in aqueous solvents, and it is OK
to use a good breath of air on the filter surface and either a Qtip or wipe
to clean it. A water dampened Qtip or cloth followed by a dry wipe should
be fine as well.
-Dan
Dan Osborn
Product Marketing Manager
Omega Optical, Inc.
Delta Campus
Omega Drive
Brattleboro, VT 05301
Phone: Direct line: (802) 251-7305 or Toll Free: (866)-488-1064
Fax: 802-254-3937
Email: [log in to unmask]
Web: www.omegafilters.com
Celebrating 40 Years
-----Original Message-----
From: Confocal Microscopy List [mailto:[log in to unmask]] On
Behalf Of Craig Brideau
Sent: Wednesday, October 07, 2009 1:53 PM
To: [log in to unmask]
Subject: Re: cleaning of filters
I usually clean coated optics with a single swipe of methanol on a lens
tissue. Take a lens tissue and fold it a few times, put a drop or two of
methanol on it, and do a single swipe across the surface.
If the fingerprint refuses to come off, refold the tissue you just used to
expose a clean surface, add another drop of methanol and swipe again. If
you are uncertain that your particular coatings are Methanol-compatible then
test a tiny corner of the optic first!
Also, make sure to use 'molecular grade' or ultra-high purity methanol, as
standard stuff contains things that will contaminate your optic.
Craig
On Wed, Oct 7, 2009 at 11:42 AM, Carl Boswell <[log in to unmask]>
wrote:
> Hi all,
> I have some emission filters with dust that will not blow off, and one
> with an obvious fingerprint, all of which show up as blurry smutz in
> the image. I appreciate the need for caution when cleaning filters
> with soft coatings; e.g. no organic solvents, no touching, etc. But
> what about a simple soak in dilute soap and water, followed by dH2O
> rinse? Or, will a polymerizing cleaners, such as Photonic's First
> Contact work? Obviously there is a solvent in this to keep the material
liquid until applied.
>
> Thanks,
>
> c
>
> Carl A. Boswell, Ph.D.
> Molecular and Cellular Biology
> University of Arizona
> 520-954-7053
> FAX 520-621-3709
>
|
