Re: [ATM] re: Film availability

[Ken Hunter <atm_ken_hunter@yahoo.com>]

Seems to me that any coating on the CCD window that
emits energy at any wavelength would just confuse the
image as it is not focused on the detector. The same
effect as dust on the window producing "doughnuts".

If it's not in the focal plane, it won't be in focus.

Ken Hunter


--- Don Clement <clement.focuser@verizon.net> wrote:

> The way that the florescent yellow "highlighter"
> coating works is to
> fluoresce when exposed UV and re-emit at a lower
> frequency.  The coating is
> mostly transparent at lower frequencies. If the 
> florescent coating were on
> the outside of the optics or ccd window then
> transmission through the window
> would be at the lower frequency. So a special UV
> transmission material, such
> a quartz window,  would not be needed. One would
> only need to coat the
> window of a standard ccd with florescent yellow
> "highlighter" if used with
> reflective optics, like a Newtonian, or coat the
> front surface of refractive
> optics.
> 
> Don Clement
> Running Springs, California
> 
> 
> > Quoting Don Clement <clement.focuser@verizon.net>:
> >
> > > If I were interested in extending the range of
> my ccd,  I would try
> using a
> > > florescent yellow "highlighter" on the outside
> ccd window. The use of a
> > > florescent yellow "highlighter"is such a simple
> elegant solution to
> > > extending ccd range into UV, that I think it
> would be worth trying. The
> fact
> > > that the ccd window (or even transmitting
> optics)  would not have to be
> of a
> > > special UV transmitting material, makes this
> method worth looking into.
> I
> > > believe at least one of the Hubble ccds used a
> similar method.
> > >
> >
> > When I bought my eprom eraser, they mentioned that
> the glass to make the
> tube
> > required special transmission charachteristics to
> transmit the uv.  Most
> glass
> > absorbs uv.  Yellow highlighter sounds like it
> might 'shift' the ranges,
> but I
> > can't see it causing increased transmission.
> >
> > Hermit, holed up in Youngstown, Ohio
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> >
> 
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 



		
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