Collimating Celestron 12x60 binoculars

[Ags]

I suspect my Skymaster 12x60 LER FOV 5.3° binocular is miscollimated. Does anyone know a guide to collimating them? Also how can I prove the binoculars are out of collimation?

[Mark at Beaufort]

12 minutes ago, Ags said:

I suspect my Skymaster 12x60 LER FOV 5.3° binocular is miscollimated. Does anyone know a guide to collimating them? Also how can I prove the binoculars are out of collimation?

Agnes hopefully Steve Tonkin @BinocularSky will see it and advise.

[Ags]

I found a video online showing where the little collimation screws are hidden so I a bit of progress.

[Nik271]

49 minutes ago, Ags said:

I found a video online showing where the little collimation screws are hidden so I a bit of progress.

If you have found the screws you are halfway there. The other main thing is how to measure miscollimation more precisely. Here is how I do it: in daytime set binoculars on a tripod and focus on a distant target, it has to be far enough that you cannot observe the parallax between your eyes.

Set the IP  distance so it fits your eyes and then gradually move your head away from the eyepieces by about 20 -30 cm while keeping looking through them switching from left eye to right and back  You will find that even  a small misalllignment in the two views is greatly magnified this way and with the screws you will be able to adjust.

 

Bear in mind this way the binoculars are collimated only at this IP distance so it's is not a perfect fix. 

[Ags]

Thanks, I want to like these binoculars, but I have only been able to use them as a very heavy monocular.

By the way the video was for the Skymaster 15x70, but the screws are in the same place. Setting up the binoculars and backing off 20 cm makes sense and I will try that.

Edited November 19, 2021 by Ags

[Nik271]

PS. Actually in almost any binocular there will be a small misalignment but the brain can deal with it up to certain point. If your eyes get tired or you get headache this is a sure sign of large misalignment. Also if the left eye view is shifted right that's fine, we just interpret this as stereo vision. View shifting up,  down or leftward ( from left eye ) is really bad as brain is not used to it.

 

[PeterW]

Decent bins will have very little misalignment, both tubes will be cowlings and also aligned to the central IPD axis… so adjusting the IPD doesn’t affect the collimation. If you look at a bright star/planet and close one eye alternately or suddenly open both eyes if there are two images or the image jumps then the tubes aren’t properly aligned. 
you can poke about and adjust stuff, there are videos, but there may be other adjustment (some rotate the objective lenses) and without the right collimation kit you can’t get everything lined up properly. If you can get it acceptable then threat, but it’s not too expensive to get someone to do the job properly.

 

Peter

[Ags]

The binoculars now appear to be aligned correctly. I didn't adjust anything, just showed the bins the screwdriver and it got its act together sharpish!

Guess it wasn't collimation, I just struggle on an epic level with setting the IPD. I had to get that right before I started collimating, so I tried taking off my glasses and using them as a template for spreading the eyepieces. Having done that I got a lovely 3D view of the Moon, which was also much steadier as I was using the correct holding technique shared by @BinocularSky recently.

[PeterW]

Good to hear things have settled down. I once disassembled a pair of wonky bins, reassembled (no collimation twiddling) and it magically was fixed…. Great when it happen. Enjoy the view!

Peter