Re: ATM Secondary flatness...

[Anthony Stillman <atmer@flash.net>]

Good primary, good secondary, good eyepiece, good collimation -> good telescope
BAD primary, good secondary, good eyepiece, good collimation -> BAD
telescope Good primary, BAD secondary, good eyepiece, good collimation ->
BAD telescope Good primary, good secondary, BAD eyepiece, good collimation
-> BAD telescope
Good primary, good secondary, good eyepiece, BAD collimation -> BAD telescope

At least the last one doesn't cost much to fix.  And, compared to the time
you put in figuring the primary and collimating, even a really good (read
expensive) secondary and occular are cheap.


Anthony

PS Regarding your question.  After more than three decades of viewing, I
can see the difference between 1/8 wave optics and 1/100 wave optics but
only when the seeing is extraodinary, the mount is stable, and I'm kissing
up to the owner.