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Subject: [M]: Re: Star test help
From: Tom Whicker
Reply To: mapug@shore.net
Date: Sat Aug 09 00:18:28 1997


A three lobed star test is very common in Meade SCTs. It is not the
result of bad seeing. Bad seeing will produce a wild assortment of
flickering patterns. But any lobes that are visible in the same
orientation on a repeated basis.....these are evidence of poor optics.

Of course, you must collimate to your best ability first. And eliminate
diagonals and other extraneous sources of distortion.

The bottom line is: quality control at Meade says a 1.5 arc second,
three-lobed star image is plenty good for the mass audience. That's why
the magazine ads don't mention the phrase "diffraction limited".

Tom Whicker
Chapel Hill, NC