One off collimation question.

[Rapallokid]

I am having difficulty collimating a 300mm Revelation Dob. However I am happy to keep persevering with all of the advise available here and also guidance available like andys shot glass etc.

My question is about using a cheshire and laser collimator. If I use the cheshire I get a fairly good result but when I then check the result using the cheshire it does not match up!

BTW The laser is one of the long ones.

Is this normal, should only one method be used. In my mind they should yeild the same result.

Any advise would be appreciated.

RK

[Tinker1947]

Check the Laser is collimated, if its a round type put it in a "V" shaped block a couple of nails or screws in a piece of wood, then roll it and make sure the dot stays in the same place on a wall. The Chesire will be accurate..

[Rapallokid]

Thanks Tinker 1947 much appreciated.

[Northern Soul man]

Hi Ya Rapollo, I've got the same dob and was collimating last night before a very cold session, I've placed a dot on the primary, cause having such a short focal length with rather a large primary throws up difficulties with my Cheshire (its the one with the engraved concentric circles on - looking down the focuser I can just see the mirror clips on the primary, but when the collimaters in line - this hides them, think I've finally got it lined up though - seeing was really good last nite here in the Midlands and watched the transit of the GRS Amazing!!!. I set the LX90 and did a little side by side comparison, and the Dob just pipped the Meade, a much brighter Jupiter, and as I say Fantastic Seeing - a really steady atmosphere. I wouldn't worry too much, if you can get it near to collimation, personally I dont think the dob being slightly out of collimation will hurt - just nice to go out and observe - The Atmosphere will have a greater effect on seeing than a slightly misaligned optics I think - Take Care and hope your having as much fun with the scope as I am - Clear Skies mate Paul.