Laser Collimating

[Danwoodward7]

Hi all,

I have bought a laser colminator and have tried to use it.....just wondering if anybody can tell me why the red dot which is bouncing back onto the target on the collminator itself is not a small dot like in all the tutorials I have watched......mine is very a large faint dot which covers the entire target?

Thanks

Dan

[Ricochet]

What scope do you have? Is there a lens built into the focuser?

[Danwoodward7]

Yes I believe there is....I have got a visionary Mira ceti 150

[brantuk]

You should see a sharp intense dot in the center of the target if it's collimated well. Your collimator itself might need collimating first. The tool has to be right before it can be used - it's a bit like having a drill bit that's not centered in the chuck. Hth

[BeanerSA]

Yes I believe there is....I have got a visionary Mira ceti 150

This appears to be a Bird-Jones and are notoriously difficult to collimate.

[Ricochet]

If your mirror has a centre spot then you may be able to collimate the primary by looking for the shadow of the centre spot on the target as done with a barlowed laser collimation.

I believe that to fully collimate a Jones-Bird you would normally start by disassembling the focuser in order to remove the lens which creates the extra difficulty.

[Cornelius Varley]

If it is this one http://www.clearviewbinoculars.co.uk/acatalog/Visionary_Mira_Ceti_1400_150.html aperture 150, focal length 1400, then you won't be able to collimate the telescope with a laser. Either use a cheshire eyepiece or a colli-cap   http://www.firstlightoptics.com/other-collimation-tools/cheshire-collimating-eyepiece.html and http://www.firstlightoptics.com/other-collimation-tools/rigel-aline-collimation-cap.html

[Danwoodward7]

Yes that is the one....thanks everyone for their help!better buy a Cheshire eyepiece then