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Binoviewer collimation

Started by Goggles, 02/03/2003 07:41AM
Posted 02/03/2003 07:41AM Opening Post
Hi,

I recently purchased a Celestron (Baader) 60 degree binoviewer from Astronomics. It made a big difference to planetary detail on my chromacor equipped 150mm Synta, significantly improving contrast.

I put my laser collimator in one of the eyepiece holders, and the spot on the objective lens is about 15 mm off centre. I know that it's not the focuser's fault as it's a Burgess, and rotating the bino in the focuser also rotates the spot around the centre of the objective lens.

Can I have some opinions on whether the miscollimation is important enough to affect the quality of the view, given that the light cone should be hitting the centre of bino opening and that the total angular error from the eyepeice/laser side is in the order of 42 arcseconds.

Considering that I paid about $1000 CAD for it, I wonder if I should send it back to Baader for recollimation or else...

Regards,

Marc Landreville
Posted 02/03/2003 09:49AM #1
Hi Marc. It may be *neither* the Burgess nor the viewer.

Two questions came to mind:

-Where does the laser beam strike the objective when the viewer is removed (i.e. checking alignment of the focuser itself)? True, the Burgess may be perfectly square, but I'm wondering about the main tube itself, and/or the focuser's mounting flange. I'm guessing you've already checked alignment of the focuser, but I thought I'd ask, anyway.

-When placed in the *other* eyepiece collar, where does the beam land (relative to the first collar's spot)?

My "gut" tells me a ~15mm offset/tilt may be practically invisible at the 150's eyepiece. (Of course, I could be completely wrong.) However, if the other collar shows a significantly different/"conflicting" offset, merging the binocular images may be troublesome.

If significant astigmatism is being introduced, you should be able to see the aberration in a star test (one eyepiece at a time, in the viewer).

Best wishes and luck.
-Dan