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ZEISS. Discover the fascinating world of birds, and win a birding trip to Columbia

Collimation (1 Viewer)

HoodieOR

Member
United States
Last week I sold a Maven B6 12x50 to a gentleman on another forum. I had spent maybe 6 hours total behind the binoculars with them tripod mounted before I sold them. I never noticed any eye strain. He contacted me after being able to use them and informed me that he thought the alignment of the barrels was off. He explained the common powerline test you can use to check for this, which I had never done before. I offered to take them back so he wouldn't have to deal with the hassle of warranty service, and they are on their way back to me right now.

This led me to check my new B1.2 8x42. I set them up on a tripod, focused on a powerline about 300 yards away, and backed away slowly until I could see through both barrels individually. Sure enough, there was a vertical gap in the powerline from one barrel to the other. I just filled out the warranty paperwork and will be sending them in. I did the same test on my roommate's C1 8x42 and the effect was still there, but much smaller.

I have a few questions for those with way more optics knowledge than me:

1) Is this a big deal?

2) Is it this common for basically new binoculars in this price range to have this issue, or did I just get particularly unlucky?
 

zzzzzz

Well-known member
Canada
Try this greatestbinoculars: how to check the collimation of your binocular
collimation%20check%201%20(1).jpg

A trinocular! And behind it a two headed guy is watching you.

This means proper collimation.

Here is the document by “Rafael Chamón Cobos” Tobias referenced 5 - Nuevos artículos - Collimation of Binoculars with a Lamp, a Mirror and a Screen (recommended)
 
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Binastro

Well-known member
It is a big deal, depending how much misalignment there is.

There is no perfect collimation, but an expensive binocular should be well within limits and keep the level of collimation for a long time unless subject to a serious jolt.

In my experience poor collimation and moisture, fungus etc. are the two most common faults with used binoculars.

With new binoculars, generally I find that expensive ones are well collimated, but cheaper ones are often out of collimation.

If there is eye strain it could be the binocular or a person's eyes or both.

One does not want eye strain.

Regards,
B.
 

pat mitchel

Well-known member
One thing to be cognizant of- YOU may not be collimated. There's a medical eye situation called "prism" where one eye see in a different plane than the other. Some people also have more accommodation to collimation errors than others. Pat
 

HoodieOR

Member
United States
One thing to be cognizant of- YOU may not be collimated. There's a medical eye situation called "prism" where one eye see in a different plane than the other. Some people also have more accommodation to collimation errors than others. Pat

This sort of thing was one of my main concerns.

I have very different prescriptions in each eye. And I need correction for prism. I'll hold off on sending the 8x42 off until I can have someone else see if they can duplicate the effect.
 

zzzzzz

Well-known member
Canada
The US and Soviet Alignment Standards for binoculars, establish tolerances for three types of misalignment between both optical axes at the exit pupil:
  • maximum Horizontal Divergence,
  • maximum Horizontal Convergence and
  • maximum Vertical Divergence.
A small amount of Divergence is allowed. SeeAttachments
 

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Binastro

Well-known member
One can need prism correction for close distances but not for long distance.

It can vary with time.

With spectacles the prism correction can either be by actual prism or by displacing the optical centres of the lenses.

Having someone who doesn't need prism correction test binoculars seems sensible.

B.
 

HoodieOR

Member
United States
Update.

Had my girlfriend check and she couldn't create the effect. I also checked again and it wasn't as noticeable for me the second time around. I'm sure this isn't the most precise way to check for issues, so I'm going to have multiple people look at the B6 that's being returned to me before I contact Maven about it.

This seems like one of those deals where if you aren't experiencing problems in regular use it's best not to go looking for them.

Appreciate all the advice.
 

pat mitchel

Well-known member
MY pathetic quick test is a look at a distant object, pulling away the binos quickly and see if the eyes seem to revert to a relaxed/ focused view instantly or take a sec to gain correlation to each other. But then again, I mostly mess with porros (which often need work- sigh!) Regards, Pat
 

pat mitchel

Well-known member
I should mention that at least with porros, you can aim at a bright star, focus on said star, the move the diopter adjust all the way to the opposite side of what you need for true correction. If the defocused view of the star is overlapping the sharp view then the collimation should be darn close. Pat
 

Rg548

Well-known member
United Kingdom
It can depend on the individual.

I bought some Zeiss 8x56T*FL's from a dealer, and my thoughts were that the collimation was just a hairs breadth out. The dealer disagreed, saying they were perfect, and I believe to him, they were. My mate also couldn't detect it.... so fair enough.
But I never quite settled with them, so sent them off, and the report was.... that they were so slightly out of collimation that the engineer was surprised I had noticed !!

I also told a dealer his demo Vortex binoculars were out, to which he disagreed, but went out the back of his shop, and came back 5 minutes later saying indeed I was correct.

What I would say, is if YOU can't notice eye strain, then don't worry.

The 'pathetic quick test' mentioned in post#10, of focussing on something for a few seconds, the taking the binos down, and seeing if your eyes feel settled, has never let me down..... and proves to be a bomb proof test, to me anyway!!
 

jring

Well-known member
Hi,

the easiest way to check for correct collimation of binoculars is to observe a bright star and bring the bins to best focus. If you see two stars instead of one, your bins are quite a bit out of collimation. But if there is only one, that does not mean all is well, the brain corrects this but observe that way for an hour or two and you might get a headache.
You then turn your diopter all the way to one side so one tube is defocussed a lot. You now see a star and a faint disc. Since those are sufficiently different, the brain will not try to merge the images and you can check whether the star is in the middle of the disc or not...

Joachim
 
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WJC

Well-known member
Hi,

the easiest way to check for correct collimation of binoculars is to observe a bright star and bring the bins to best focus. If you see two stars instead of one, your bins are quite a bit out of collimation. But if there is only one, that does not mean all is well, the brain corrects this but observe that way for an hour or two and you might get a headache.
You then turn your diopter all the way to one side so one tube is defocussed a lot. You now see a star and a faint disc. Since those are sufficiently different, the brain will not try to merge the images and you can check whether the star is in the middle of the disc or not...

Joachim
Spatial accommodation. Not every— or even most — anomalies relate to opto/mechanical … the binocular.
 

WJC

Well-known member
Hi,

the easiest way to check for correct collimation of binoculars is to observe a bright star and bring the bins to best focus. If you see two stars instead of one, your bins are quite a bit out of collimation. But if there is only one, that does not mean all is well, the brain corrects this but observe that way for an hour or two and you might get a headache.
You then turn your diopter all the way to one side so one tube is defocussed a lot. You now see a star and a faint disc. Since those are sufficiently different, the brain will not try to merge the images and you can check whether the star is in the middle of the disc or not...

Joachim
I did reply and see no reason to do it again.
 
ZEISS. Discover the fascinating world of birds, and win a birding trip to Columbia
ZEISS. Discover the fascinating world of birds, and win a birding trip to Colombia
ZEISS. Discover the fascinating world of birds, and win a birding trip to Colombia

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