View Single Post
  #1  
Old 11-10-2010, 06:15 PM
asimov's Avatar
asimov (John)
Planet photographer

asimov is offline
 
Join Date: May 2005
Location: Bundaberg
Posts: 8,819
C11 collimation with artificial star

Made myself an artificial star today (yeah it's cloudy).

It was done with a xmas light running on a bank of 4 'AAA' batteries. Whilst not the best artificial star method, I found by concentrating (see pic 1) on one little point of light within the globe itself was more than sufficient to suit my needs.

The last time I collimated this scope was close to 12 months ago & it was only a fraction out - 1 little tweek of 1 screw was all that was needed to get it on the money.

9800mm is a conservative estimate; 3X barlow + 4" extension tube. Collimation was by eye, & then confirmed with an Imaging source camera (DBK).

Pic 2 is of the globe, & the small guage car speaker wire used to wire it up with.

Unfortunately I couldn't get the 'star' as far away as I would have liked to. This is about 75ft away where as it should have been what - about 300ft...?
Attached Thumbnails
Click for full-size image (collimation point.jpg)
48.4 KB71 views
Click for full-size image (collimation2.jpg)
93.9 KB59 views
Reply With Quote