CCD-world: Pleas help TASS

[Bruce Truax]

The following was posted to CCD-world:

In a well worded email message written on 5/8/00 1:07 PM droege at wwa.com 
said:

>Thanks for the comments.  I am already into the window fog problem.  So I
>am heating the outside of the camera.  I may have made a mistake in putting
>the CCD pretty close to the window.  About 7 mm.  I am struggling now with
>the decision to change the spacing to move the CCD further away from the
>window.  I made it as close as possible so that it would be easier to get
>to a focus.  I have focus room to spare now that I have the lenses.  Any
>comments?


Before you change your window spacing, you should carefully consider the 
effect this change will have on ghost images.  The advantage to moving 
the CCD back from the window is the ghost images will become larger and 
decrease in intensity.  If you make the distance large enough, and you 
antireflection coat the window, you can make the ghosts disappear for 
most cases.

Bruce


____________________________________________________________
Bruce E. Truax                Optical Engineering Consultant
Truax Associates              email:  btruax at home.com
388 Wedgewood Road            voice:  860-276-0450
Southington, CT  06489        fax:    860-620-9026
_____________________________________________________________

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