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#21
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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 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.496 / Virus Database: 295 - Release Date: 03/07/2003 |
#22
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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 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + |
#23
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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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