Archive for March, 2009

Moon pictures, and considerations about collimation…

I took a couple of pictures of the Moon with my Celestron 9″1/4 schmidt-cassegrain and was quite satisfied with the result, compared to other pictures taken later in November.

Pictures taken on 2/1/2009 by 8.30 PM PST, with Orion Startshoot solar system imager II, and processed with Registax and Painshop Pro.

Theophilius, Cyrillius, and CatharinaStofler  and MaurolycusLicetus and Cuvier

Besides ok conditions, collimation made here the difference.  I clearly noticed that a poor collimation combined with turbulence seems to worsen quality of  images.  Seeing conditions being equal – even with turbulence – a better  collimation will very significantly increase the image quality.

Check the very comprehensive page of Thierry Legault on the impact of collimation on image quality.

I recently bought Bob’s knobs collimation thumbscrews, and it allows me to quickly collimate my SCT (looking in the eyepiece and at the same time moving the screws to achieve collimation…).

I looked at many threads / forum discussing laser collimation tools and it seems no collimation tool is perfect.  Star collimation is quite fast with Knobs  on the secondary of the SCT  and allows to achieve an acceptable collimation even if seeing condition are not perfect.  And the price of collimation knobs has nothing to do with pricey’s laser collimation tools…

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