How is this collimation?

[barbulo]

How do your experienced eyes see this collimation?

[Pixies]

It's hard to say for sure. It's probably fine for visual observations - you can check with a star test.

If you want to be precise though, you would do better with a bright background behind the secondary, so that we can see the circles of the focuser and secondary mirror, so that we can check they are concentric.

 

 

[Pitch Black Skies]

Looks collimated to me. Quite dark as pixies has mentioned.

[Stu1smartcookie]

As Pixies said ... best do a star test . I think collimation is made harder by the fact that we are always critical of our own efforts ... the proof of this particular pudding is to look through the scope and defocus on a bright star ( use a low-ish power EP) If you see concentric circles and  the donut is in the middle then its fine . Don't get too hung up on collimation if you are just into viewing . 

[ScouseSpaceCadet]

Looks fine. Ideally put a sheet of A4 inside the ota facing the focuser and with the scope facing a bright light take a photo through the collimator. That should highlight the centre much better for evaluation.

[Spile]

I would retake the photo through a Cheshire eyepiece and sight tube combination tool.

[barbulo]

Thank you all.
I forgot to mention that I used a laser collimator and that my purpose is AP. 
I’m also dealing with traces of coma in my pictures (backfocus?) so I need clear skies to check. 

[Pixies]

Do you have a Cheshire / sight-tube? You need something like that to confirm your secondary mirror is aligned under the focuser and not twisted. A laser won't help with that.

Or alternatively a concentre?

[barbulo]

No, I don’t. I’ll have to get one. 

[discardedastro]

Coma is very much to be expected and the MPCC is not a great corrector. I'd try some photos with and without it and try CCDinspector (there's a trial) on a really star-rich field (pick a nice spot in the milky way and not too long an exposure). I still had quite a bit of visible "coma" effects till I upgraded (to a Paracorr, but the GSO corrector is also apparently very decent, etc). I wouldn't be too quick to pin that on collimation.

As others have said you will need a Cheshire at the least to get the secondary about right, laser or no.

[barbulo]

Thank you very much @discardedastro

I’ll get a Cheshire and do some corrections in the MPCC backfocus distance before giving up. 

[Pitch Black Skies]

I've seen a bit of conflicting information on what a Cheshire looks like. Can anyone clarify?

[discardedastro]

13 minutes ago, Pitch Black Skies said:

I've seen a bit of conflicting information on what a Cheshire looks like. Can anyone clarify?

https://en.wikipedia.org/wiki/Cheshire_eyepiece

Wikipedia has it right! The Concenter is another useful tool to have in the toolbox. If you've got a Barlow lens (and laser) to hand, also have a search around for Barlowed laser collimation. Between those tools you can definitely achieve excellent collimation. Vic Menard's book is also well worth owning if you're a Newt owner!

[Pitch Black Skies]

14 minutes ago, discardedastro said:

https://en.wikipedia.org/wiki/Cheshire_eyepiece

Wikipedia has it right! The Concenter is another useful tool to have in the toolbox. If you've got a Barlow lens (and laser) to hand, also have a search around for Barlowed laser collimation. Between those tools you can definitely achieve excellent collimation. Vic Menard's book is also well worth owning if you're a Newt owner!

Cool, I have one in that case. It's the premium Stellalyra one from FLO, a great bit of kit. I only use it for the secondary alignment though which doesn't really move unless I start messing about with it. I'll then carefully use a laser for the tilt of both mirrors and finish off with a collimation cap to verify everything.

I've tried Barlowing the laser before but didn't really see much benefit of it over just using the laser alone.

I must look out for that book, cheers.