Re: [APML] life of a CCD (and Filters)

[lkt <tan@cox.net>]

I spoke with David Marcus of Custom Scientific about this and he told me
that the coatings on their RGB filters do degrade with time and
moisture. He advised me to keep them in a dry environment with Silica
Gel. 

Loke




Chuck Vaughn wrote:
> 
> Mike,
> 
> > I noticed that the link showing the graphs was no longer
> > available.
> 
> Re-read my post. I re-posted the graph at the new link.
> 
> > But, I did find the discussion about cloudy RGB filters which had
> > to be replaced.  Maybe it was some sort of air pollution.   Here's
> > the email thread:
> 
> > Tan Wei Leong <weileong@singnet.com.sg> wrote:
> 
> >> I just took my CFW8 filter out for cleaning. Noticed that the "other" side
> >> of the RGB filters are cloudy, tried to clean it but can get it off. I think
> >> the coatings are bad already.
> 
> I think it is more likely that the coatings were poorly done. But if you
> can prove that air pollution degraded coatings (from acids?) then cleaning
> them on a regular basis would be a good idea.
> 
> Chuck <aa6g@aa6g.org>
> 
> ----------------------
> 
> >> I wouldn't be so sure about that either. :-) Were you around when
> >> I ran the filter cleaning test? If not, here is my summary.
> >>
> >> http://astro.umsystem.edu/apml/ARCHIVES/APR98/msg00611.html
> >>
> >> The image is now located here:
> >>
> >> http://www.aa6g.org/Astronomy/clean_test.gif  (60KB)
> >>
> >> Chuck
> 
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