Jump to content

Banner.jpg.b89429c566825f6ab32bcafbada449c9.jpg

How to do a star test and what's the theory behind it?


Recommended Posts

Hi all...I was wonder how to do a star test and what's the theory behind it?

I've searched here and used google to search here too, but can't find a definitive result.

Can some one point me in the right direct?

It's for my new 80mm refractor.

:)

Link to comment
Share on other sites

Hopefully you found this excellent reference

Diffraction pattern and aberrations

The theory behind the test to to view the shape and detail of the Airy disk and surrounding diffraction rings close to focus. The various distortions seen inside and outside focus give an indication of possible optical problems/ aberrations.

Needs very good steady seeing conditions and should be repeated a few times before making an evaluation.

Suiter's book is very good and covers the whole subject in great depth.

Link to comment
Share on other sites

*thumbs up*

I had a go last night and it makes sense. However, I think a higher powered EP is in order.

I'll do it a few times like you say. Get a good spread to average out.

edit: You're link is excellent...thanks :)

Link to comment
Share on other sites

I recently discovered it is a good idea not to have any stresses on the OTA. When scrutinizing results a poorly balance, overly tight collimation screws, warm OTA, natural flexing can all play there part in giving you a less than desirable pattern. Polaris is a good choice for a star test as this is often when the OTA is at it's least stressed position and is still bright enough to offer a good star tests.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.