not ANOTHER collimation issuePosted By Nathan Murphy |
i must apologize in advance - i've read enough forums, talked to enough people, etc. to know more than i ever wnated to know about how to collimate my newtonion reflecting telescope. none of us need another question about collimation. i am, however, at my wits end to explain the following phenomenon:
my new orion xt8 came with a neat little collimation cap -a focuser dust cap with a shiny underside and a small hole in the middle. i later bought a laser. it's an antares single beam type.
i've practiced collimating with the cap so much, i enjoy it, and am lobbying for it to be an olympic sport in 2008.
so why, when i collimate my scope with my cap (the hole-in-the-dust-cap contraption), then check it with my brand-new single beam laser, does the beam hit 1.5" from the center of the primary?!
what is going on? focuser not square? secondary not concentric with focuser? collimator out of collimation? rift in space-time continuum?
i briefly checked that my laser was collimated. i quickly went through floyd's article (i told you i did my homework) and the beam doesn't move more than 1/8" at 10ish feet.
also - the star test (i've even been reading dick suiter's book) looks about right when i collimate with the cap, but i haven't looked yet with laser collimation.
assume, for the sake of argument, i went through the correct collimation procedure for both the laser and the cap.
scope is 203mm, 1200mm FL F5.91
thanks, nate
my new orion xt8 came with a neat little collimation cap -a focuser dust cap with a shiny underside and a small hole in the middle. i later bought a laser. it's an antares single beam type.
i've practiced collimating with the cap so much, i enjoy it, and am lobbying for it to be an olympic sport in 2008.
so why, when i collimate my scope with my cap (the hole-in-the-dust-cap contraption), then check it with my brand-new single beam laser, does the beam hit 1.5" from the center of the primary?!
what is going on? focuser not square? secondary not concentric with focuser? collimator out of collimation? rift in space-time continuum?
i briefly checked that my laser was collimated. i quickly went through floyd's article (i told you i did my homework) and the beam doesn't move more than 1/8" at 10ish feet.
also - the star test (i've even been reading dick suiter's book) looks about right when i collimate with the cap, but i haven't looked yet with laser collimation.
assume, for the sake of argument, i went through the correct collimation procedure for both the laser and the cap.
scope is 203mm, 1200mm FL F5.91
thanks, nate