Re: segmented mirror for personal telescope
- From: "Bob May" <bobmay@xxxxxxxxxxx>
- Date: Thu, 20 Apr 2006 17:30:42 -0700
Off the top of my head, you need something about F12 for a 6" mirror to meet
the Raleigh Criteria which is 1/4 wave accuracy. I'll note that this works
only at the center of the parabola. Off-axis, you end up needing to be even
more accurate to the parabola. I built a 10" mirror with a 40' focal length
for sun viewing. Tried it out and found that with the winter sun at
approximately noon here in the south, the difference in focal length between
the sagittal and tangential directions was about 6'!
--
Why do penguins walk so far to get to their nesting grounds?
.
- References:
- segmented mirror for personal telescope
- From: apeneck
- Re: segmented mirror for personal telescope
- From: Bob May
- Re: segmented mirror for personal telescope
- From: apeneck
- segmented mirror for personal telescope
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