These Cheshire collimator thingies

[the lemming]

Any ideas how they work?

I inderstand the principles but as yet I have not masterer the practical. So, how do I use a Cheshire thingie?

And is it better to go all Star Wars and get a laser?

[jabberwocky]

In the simplest terms, you put it in your focuser, look through the small hole and then twiddle knobs to get everything lined up

i find they over complicate adjusting the secondary but are great for adjusting the primary.

i use a homemade collimation cap for the secondary.

ive never used a laser collimater but apparently coupled with a Barlow lens make adjusting the primary a doddle.

google astrobabys guide to collimation, explains everything brilliantly.

[RikM]

As above.

Put it in the focuser and make sure the secondary looks round and is in the centre of the tube part of the Cheshire sight tube.

Fiddle the secondary adjusters until the Cheshire crosshairs line up over the doughnut on the primary.

Twiddle the primary knobs until the black dot, lines up with the doughnut as well. The first time, you may find that this moves the doughnut away from the crosshairs.

Go back to the secondary and line it back up again, then do the primary again and you will find the doughnut should move less this time.

Repeat until the clouds go away

[lestergibson]

I was freaking out about collimation when I started but this video really helped me out. I checked out dozens of em but I found that this one was the most helpful one for me. When I tried collimation for the first time, I found it hard to understand what I was actually seeing through the draw tube and collimator, what with all the reflections etc. but this video really helped