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Sensor plane or collimation first for Celestron 9.25 XLT?

Celestron SCTs 2 replies51 views
Jim Milling avatar

Getting my my equipment figured out and I’ve discovered a few issues that need addressing. While I think Ive got my spacings figured out with a little tweaking after some new adapters come in. The two issues I know of at this point is Camera sensor plane is off on all telescopes I’ve experimented with. Going forward my plan is to use Williams Optics RedCat61 for wide field stuff obviously with some 2x Televue Powermate added for some increased focal length. The second issue is collimating my Celestron 9.25 XLT SCT, which is why I’m asking here. Should I worry about the sensor plane issue first before trying to collimate? My intuition tells me that sensor plane issue shouldn’t greatly affect collimating as I’ll be centering the out of focus star. The problem is when adjusting I’ll need to move the star off center and therefore sensor plan could come into ?play? I’m guessing sensor plane adjustment will become a regular thing if make adjustments to image train for different scopes? Trying to do things differently and ask for help before trying to figure it all out so appreciate any feedback.

Thanks, Jim

P.S. I’ve posted a few pictures already. I think that the focal plane issue is something that can be looked at when viewing them; If not I can post any info that would be helpful to you in accessing.

Tony Gondola avatar

You always be making collimation adjustments with the star centered. It will move off center after an adjustment but you always need to bring it back to center again before making a judgement and adjusting again. Hope that makes sense.

On your question and because of the above, take care of your collimation first.

andrea tasselli avatar

Collimation should be done at native focal length and thus spacing isn’t really a concern.