Best way to collimate my Skywatcher Dob?

Andrew1972 · (#1)

Just got my first Dobsonian - a second hand 10" Skywatcher flextube.

I've not even unpacked it yet and i'm already thinking about collimation! For starters I presume i should get it set-up and have a look through it although what is the best way to test the collimation of the scope, the best way to collimate it, and what is the best tool to do it? I'm a novice with regards collimation so advice from the basics up would be much appreciated.

Many thanks,

Andrew

irishbloke · (#2)

The best tool is probably a cheshire collimating eyepeice. It allows you to judge the shape of the secondary mirror to align it properly and then has crosshairs and sight hole used to collimate the primary. I also have a colli cap, £6.50 i think, which is helpful for seeing the whole primary mirror in the secondary in stage one.

I have a lazer but recognise that it's probably not align just right But is still effective witht he lazer barlowed collimation method.

I have the solid tube 10" skywatcher and love it. I have learnt alot bout collimating it recently and would recommend the coli cap and cheshire and Astro Baby's tutorial. Work through it and you will come to understand why you are doing what you are doing.

Enjoy
Brian

Ben Ritchie · (#3)

Easiest way to test it is a simple star-test, defocus a star and look for the symmetry (or not) diffraction rings.

My favourite tools to collimate are the Catseye set of sight-tube, cheshire and autocollimator, but this

Collimation - Cheshire Collimating Eyepiece

is a much cheaper alternative and works very well once you figure out the process, there are some good tutorials online (e.g. Astro Baby's one).

Andrew1972 · (#4)

Thanks for the quick reply Brian,

Would the following be suitable from FLO?

Collimation - Celestron ColliCap

Collimation - Cheshire Collimating Eyepiece

Edited to say thanks to Ben too (you've recommended one of the above)

MAny thanks,

irishbloke · (#5)

That's the 2 that I use. I got a 2nd hand cheshire for £15 but they're not dear anyway.
Brian

dio · (#6)

Hi i have been unable to find astro baby's tutorial Astro Babys Guide to Collimation it appears that this website is down. Could some one please point me in the right direction.

Many Thanks

Doc · (#7)

Here Dio

Astro Babys Guide to Collimation