Alignment - 2012 Sep/Oct

At some point I tried to optimize the distance between the optical elements - and lost the alignment. Here some photographs showing how I try to get the alignment back.

(As usual: Click on the images to get a larger version!)

click to enlarge

I put the telescope on a frame to fix it horizontally.


I removed the secondary. I use a pinhole eyepiece and look through the focuser. The secondary holder central hole allows me to view the pinhole light source (see lower left and left center). This means that the optical axis of the primary, the focuser, and the secondary holder should be aligned.

This is how it looks like from the outside - I put a flashlight and a screen with a hole in it to generate a point light source at a distance of twice the radius of curvature. When the reflection of the light goes back precisely to the light, I know that I have found the optical axis.

Seen from the other side...

Just to double-check I put a laser collimator in the focuser. I have also marked the center of the tube with two wires. Here the issue is that I am not really sure that the laser is properly centered. I still have to figure out how to best do this.

 

Created by dvk,  29 Sep 2012
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