Anyone got a Cheshire eyepiece I can borrow ?

[RobertM]

Need to check the collimation on a refractor..

Many thanks
Robert

[JohnP]

Hi Robert - I have one... Do you mean Reflector (I'm not sure if you can use it to check a refractor)... John

[Mike]

I don't think a Cheshire will work on a Refractor. I have a laser collimator that might help.

[Ian]

certainly when I use mine on my newt, I rely on the centre spot.

I hope you don't find your scope out of collimation. That's a problem for a refractor. You've not dropped it, have you?

Seriously, the best bet would be to star test it. Of course, you need to see a star to do the test...

[RobertM]

Thanks for the offers guys.

Yes it's definitely a refractor and I'm sure the problem is collimation.  I've taken a couple of images and the stars flare out on one side, rotating the Imaging train (CCD/Filter wheel) by 180 degrees eliminates that as a cause.  Assuming it's not the stars, that leaves just the lens.  Yes I know a star test would be best but I don't fancy messing around in the dark with a tiny allen key until collimation is very close, and then who knows when a star will next appear !

Mike, as you're a bit closer than John could I pop around this evening and pick up your collimator ?  If so let me know the best time.

Many thanks
Robert

[Mike]

Robert,

Out tonight i'm afraid !

I should be in tomorrow though.

[RobertM]

No problem, I'll be in from 6pm tomorrow so any time from then on is good for me.

[Mike]

I'll PM you my mobile number. Give me a call.