Re: [ATM] Purpose of baffles/shrouds

["James Lerch" <jlerch1@tampabay.rr.com>]

Here's a graphic I threw together demonstrating the problem of how baffles 
around just the focuser area are insufficient in some cases.

http://lerch.no-ip.com/atm/Baffle_Problem.gif (14kb)

It's based on a scale drawing of one OTA of my 16" Bino, so it is a little more 
complicated than a standard Newtonian, but it demonstrates the point.

The red 'cone' is light on-axis from the primary.  The yellow line would be one 
of many paths stray light could take to enter the image plane at the focuser.  A 
large light shield on the far side of the OTA would slow this path down, but as 
previously mentioned by another poster, the stray light can still illuminate the 
inside of the light shield, which will produce the end result, but at a reduced 
level.

Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and coating site)
http://lerch.no-ip.com/ChangFa_Gen (My 15KW generator project)

"Anything that can happen, will happen" -Stephen Pollock from:
"Particle Physics for Non-Physicists: A Tour of the Microcosmos"

" Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent. "
                                                           Calvin Coolidge 

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