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View Full Version here: : Schmidt-Newtonian collimation different?


Kirkus
27-12-2007, 07:21 AM
I've become comfortable checking collimation on my Dob. But I'm wondering if collimation is done the same way on a Schmidt-Newtonian. I just bought a used 6" Meade LXD75 and after getting it home and looking through my site tube, the secondary was not centered at all to the focus tube. Anyway (I'm rambling)... I thought I'd read somewhere that the secondary mirror should be 1/8" off in two directions from regular newtonians??? Does that sound right?

I guess what I'm asking is can I collimate my new SN like I do my Dob?

Tannehill
27-12-2007, 08:41 AM
Nils Olof Carlin has a section on Schmidt-Newt Collimation on his site, it might help....

http://web.telia.com/~u41105032/kolli/kolli2.htm#schmidt

Kirkus
27-12-2007, 09:46 AM
That's perfect! Thank you so much. :)

Mark
27-12-2007, 10:01 AM
The offset you mention is correct and should have been set in the factory. The end result is, once collimated, the secondary should look slightly egg-shaped when viewed through the focuser, with the larger 'lobe' of the 'egg' pointing towards the primary.

The link posted above is a good place to start.

Mark

Kirkus
28-12-2007, 09:40 AM
That's exactly how it looks, Mark. Thank you both for the info.

William1
28-08-2009, 05:23 PM
Thank so much Dear. It might be helpful for me..







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