Quote:
Originally Posted by mikeyjames
Hi Rob
Can I just verify what you mean. There is two scopes I am now thinking about - a 200/1000 and a 200/800. Are you saying the F4 would more forgiving than the F5?
Cheers
Mick
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Even though guiding will be a bit easier at 800mm, an F4 scope is a bit trickier to collimate than F5, and the critical focus zone smaller. F4 is likely to magnify any issues with scope stability/construction versus F5.
My Newt is F5 and holds collimation very well. I don't have direct experience with F4 - again, probably worth reading around a bit here and elsewhere on the net. Remember you'll need a coma corrector (e.g. MPCC) to get a flat field in a Newt.
This thread talks about newts. More pros and cons to consider
http://www.iceinspace.com.au/forum/s...ad.php?t=96521