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Questions regarding ATM



 
 
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  #21  
Old July 5th 03, 04:40 PM
John Carruthers
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Default Questions regarding ATM

http://www.dhinds.co.uk/frames.html

6" mirror £40
in "for sale- used products"

Colin Smith

Somerset
Telephone: 01458 440366
E-Mail:
Mobile No: 07860 825942

Price: £ 40





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  #22  
Old July 5th 03, 09:09 PM
Stephen Tonkin
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Default Questions regarding ATM

#MK wrote:
f the F = 1900mm,


I wonder if he meant fl 900 (which would make it f/6)?

and a 6 inch mirror is 150mm, then is the F-Ratio: f/13 [roughly]?
Hence, it wouldn't be quite curved,


Could be left spherical, which makes it easier to make, but f/13 is a
bugger under the Foucault test. The shadows are very indistinct.


and whilst magnification would be high, would this be any good for
planetary observation


In theory it could be very good, as you could have a minute secondary.
Play with NEWT (ATM software on my web site) to see what I mean.


Best,
Stephen

--
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ Stephen Tonkin | ATM Resources; Astro-Tutorials; Astro Books +
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  #23  
Old July 5th 03, 09:09 PM
Stephen Tonkin
external usenet poster
 
Posts: n/a
Default Questions regarding ATM

#MK wrote:
f the F = 1900mm,


I wonder if he meant fl 900 (which would make it f/6)?

and a 6 inch mirror is 150mm, then is the F-Ratio: f/13 [roughly]?
Hence, it wouldn't be quite curved,


Could be left spherical, which makes it easier to make, but f/13 is a
bugger under the Foucault test. The shadows are very indistinct.


and whilst magnification would be high, would this be any good for
planetary observation


In theory it could be very good, as you could have a minute secondary.
Play with NEWT (ATM software on my web site) to see what I mean.


Best,
Stephen

--
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
+ Stephen Tonkin | ATM Resources; Astro-Tutorials; Astro Books +
+ (N51.162 E0.995) | http://www.astunit.com +
+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
 




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