Testing collimation (1 Viewer)

[new_mexico_birder]

I recently bought some used Sightron 8x32 binoculars off of eBay. I own a few pairs of binoculars and am not an expert but am not unfamiliar with them either.

I immediately noticed that image through the binos was weird. Blurry isn’t the right word for it - almost double vision but not that extreme. But I can never get it looking right. The diopter is set right for me. Not sure what else to check. I’ve never experienced binoculars with a collimation error but from what I can tell that’s what I’ve got with these.

I don’t want to bug the seller about sending me malfunctioning binoculars if this is user error. What are some things I can do to check and see if this is a collimation problem?

 

[dipped]

Hi CO_west
You can try setting the dioptre to its extreme one way and then focusing on a star with the left ocular and seeing if the star is centred in the fuzzy right ocular image (using both eyes). If not reasonably centred the binoculars are out of collimation.

 

[Ted Y.]

I suppose in this case the diopter is installed on the right eyepiece.

 

[WJC]

Hi CO_west
You can try setting the dioptre to its extreme one way and then focusing on a star with the left ocular and seeing if the star is centred in the fuzzy right ocular image (using both eyes). If not reasonably centred the binoculars are out of collimation.

" ... the binoculars are out of collimation."

If you are looking for conditional alignment only, that method will work for ONE observer. 3-AXIS COLLIMATION would require the binocular to be collimated at every IPD ... not just his.

 

[lilcrazy2]

I recently bought some used Sightron 8x32 binoculars off of eBay. I own a few pairs of binoculars and am not an expert but am not unfamiliar with them either.

I immediately noticed that image through the binos was weird. Blurry isn’t the right word for it - almost double vision but not that extreme. But I can never get it looking right. The diopter is set right for me. Not sure what else to check. I’ve never experienced binoculars with a collimation error but from what I can tell that’s what I’ve got with these.

I don’t want to bug the seller about sending me malfunctioning binoculars if this is user error. What are some things I can do to check and see if this is a collimation problem?

What Dipped advised is the standard quick test for collimation problems/issues. Since you seem to be familiar with decent optics, and if you have the IPD and diopter set correctly, I'd trust my eyes and say they are out of collimation and take it up with the seller, and if bought on ebay then file a case. Sightron has been out of the bino business for a while, so doubt if anything could be done under warranty. On the off chance you might contact them and see what can be done if anything (1-919-562-3000 or at [email protected]). Seems like Adorama has bounced the price around between $99 and $200 for the past 6 months, and unfortunately back up in price now.

 

[William Lewis]

I had a similar quandry recently and had a thread on it here - Checking collimation at home

To surmise if you point your binoculars up at a starry sky and see twice as many stars as you should the bins are out of collimation, that's the method that worked best for me anyway.

I got some vintage 10x50's back from a service and collimation today and they too seemed a bit off (likely knocked out in the post, despite being very well packaged). A quick look up at the stars tonight proved it again, 2 Jupiter's...

 

[Gijs van Ginkel]

Since collimation and conditional alignment are sometimes mixed and that may lead to confusion. This is what Bill Cook showed in his book, see the attachment.
Gijs van Ginkel

 

[WJC]

Since collimation and conditional alignment are sometimes mixed and that may lead to confusion. This is what Bill Cook showed in his book, see the attachment.
Gijs van Ginkel

I wish to thank Gijs for posting my graphic. For whatever reason, I was faced with recreating the personal information that I had offered 16 years ago to become a member. Being too busy arguing with KDP over formatting of my last book, I just didn't have time. Gijs said the graphic was from one of my bino books; it was not. However, rest assured it will be found in any subsequent books. Up to a point, the concept is good in establishing CoAl at a certain IPD and will provide all the information some observers will want to know. But like the popular mask attached, it only addresses CoAl and not clinical collimation.