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View Full Version here: : how can i focus my telescope with my neximage in


alphamone
29-04-2008, 08:50 AM
I was trying to use my neximage last night, but I encountered a major problem. I cannot focus the thing, and since the moon is not out in the early parts of the night, I do not have any large objects to focus on first before moving the scope.

if anyone has some hints on what I can do (I have an astromaster130 telescope) to make it easier to focus, such as using a different program than the one that came with the imager, or suggestions on other things to aim at, I would be greatful.

Jeff
03-05-2008, 02:55 AM
Focussing on a bright star such as Sirius should get you going. Alternately, you can try focussing on a distant object during the daytime.

Note that you may have some problems bringing the CCD camera into focus if there is insufficient inwards travel on your eyepiece focusser. If this is the case, then you can see Mike Selway's excellent guide:
Modifying a Newtonian Tube for DSLR Photography (http://www.iceinspace.com.au/index.php?id=63,441,0,0,1,0)

Hope this helps.

Dennis
03-05-2008, 07:00 AM
When you next manage to focus on the Moon, remove the Neximage and place an eyepiece into the focuser and slowly insert it until the image comes to focus WITHOUT adjusting the focus knob.

Clamp the eyepiece. Your eyepiece and Neximage are now par focal. Either mark the barrel of the eyepiece to indicate how far you had to insert it into the focuser, or use a “Parfocal Ring” (http://www.scopestuff.com/ss_par1.htm) to clamp on the eyepiece, thus registering the parfocal distance.

Then, all you do is insert the parfocal eyepiece, focus on a star, remove the eyepiece and insert your Neximage and touch up the focus on the notebook display.

Cheers

Dennis