Checking Collimation (1 Viewer)

[Conndomat]

... unless somebody knows a reason why not.

strabismus...

Schielen (Strabismus)

Schielen (Strabismus): Ursachen, Formen und Behandlung Die Fehlstellung eines Auges der eine Augenmuskelgleichgewichtsstörung zu Grunde liegt Termin beim Au

www.neue-augen.de

"Around 80% of people suffer from latent (hidden) strabismus. This usually goes unnoticed and does not cause any symptoms. In some cases, latent squinting can cause headaches, double vision or blurred vision."

Andreas

 

[henry link]

I had my SF collimated vertically and I qantify the collimation error as follows:
I put the binoculars on a tripod without moving it during the test. Look alternately with only one eye in each tube in turn and put a distant object in my right eyepiece so that it touches the edge of the FOV at "12 o'clock". Thus, in the other eyepiece, the object did not touch the edge of the FOV due to the difference in alignment between the tubes. I took a picture through the left eyepiece and calculated the deviation percentage with the object lowered towards the center and wrote the result to Zeiss. They confirmed the diversion! With your binoculars, being deviated only horizontally, the object will not descend towards the center but will be to the left or to the right of "12 o'clock"

The problem with this method is that it depends on the eyepiece field stops being in perfect vertical alignment and the magnification between the two sides being perfectly equal. I encounter many eyepiece field stops that are vertically misaligned and/or not quite the same size.

 

[Elpha8888]

I've tried the star test on many new high end optics including the SF and NL Pure and none are exactly central. No sure I've had a perfect horizontal line either, close enough. The Swarovskis have been near perfect for my eyes when using them, no issues, totally relaxed could use all day. These tests are surely just an indicator with many variables at play.
The worst culprits have been Canons usually from an online store, these have caused issues.
If the binocular performs well for your eyes I wouldn't get caught up too much in collimation, if something is wrong then it gets sent back.

 

[William Lewis]

I had a similar problem but found the easiest way is just to look at a bright star (not albireo etc) and if there is one star present the bins are probably ok, if there are 2 stars present they're out of whack. More reading here - Checking collimation at home

 

[james holdsworth]

So, I used them for two hours of heavy birding today, negligible eye strain and perfect images. I say negligible as it’s easy to imagine some eye strain when using a binocular that’s (ostensibly) out of alignment.

The question that burns though, is why the very obvious misaligment horizontally, and is this test something that can be misleading? I ask because several big optic makers list this method on their websites.

I’m talking with the rep. tomorrow and need to decide if they go back again.

 

[Trinovid]

Can anyone answer the question asked? But, both, thanks for the input.

Albie already did that in post #3.

 

[Trinovid]

One way of checking collimaton that I learned from Cloudy Nights and you might already know this is to focus on a star at night . Once it's focused as well as can be totally unfocus the one side using the diopter setting. The focused star should be inside the unfocused star's circle(blob) . As long as it's inside the circle the collimation is fine although the closer to the center the better .

Okay, heading outside tonight to look for stars. I guess if it's cloudy then I can look at the furthest street lamp I can find as a reasonable alternative.

 

[james holdsworth]

Albie already did that in post #3.

And I tried his method, and reported the results.

 

[Patudo]

Surely the correct answer is: buy ***'s book, then go about fixing it yourself? 😁

 

[pat mitchel]

I'd ask multiple persons to look through the bino's as they are pointing at a fixed horizontal line- the brickwork or eaves of a building while the binos are on a tripod- that would allow you to move the eyes away from the bino slightly to magnify (if any) mis alignment. Have you other binos to see if you perceive the same misalignment in them? Might be in your eyes and not the bino's ("prism" as it's called) Pat

 

[james holdsworth]

I'd ask multiple persons to look through the bino's as they are pointing at a fixed horizontal line- the brickwork or eaves of a building while the binos are on a tripod- that would allow you to move the eyes away from the bino slightly to magnify (if any) mis alignment. Have you other binos to see if you perceive the same misalignment in them? Might be in your eyes and not the bino's ("prism" as it's called) Pat

Post 7

Thats really what I’m getting at here..is there any reason to think this method is unreliable, given that I see an obvious offset, but star test looks OK, and manufacturer indicated binocular was in spec?

Are there any other reasons I’d see this offset between barrels BESIDES collimation error? If not, they go back.

 

[WJC]

Hello all and Season’s Greetings,

It would appear I am a tremendous failure or that some of you who like to speak so much are at a deficit when it comes to reading or listening. I have been addressing this issue—in print and lectures—for 47 years! But then, perhaps my half-century in optics, having repaired and collimated more than 12,000 binoculars, and working for the organization (the US Navy) that came up with the current procedure for the most accurate binocular collimation is somehow not good enough to please the viewers of Birdforum who think they have a better way.

1. Attached is an image of the inside of my Mk 5 collimator. I am glad someone mentioned 3-axis alignment. However, the real deal is a very simple operation but seems to lend itself to those who get an ego stroke out of making a simple procedure into something more convoluted and confusing than it needs to be.

2. I am amazed—although I should not be—that the folks who want their binoculars collimated to a level far greater than the most nitnoidy of observers could recognize have continued to want better. It’s like those who already own one of the best binoculars ever made keep needing to … drum rolls, please ... UPGRADE!

Not only has the exact procedure been described in both BINOCULARS: Fallacy & Fact (38 pages on collimation) and Understanding & Attaining 3-Axis Collimation (69 pages on Collimation) The whole book deals exclusively with the subject. Not only that, I have been posting the EXACT step-by-step procedure on Birdforum, Cloudy Nights, and others LONG before the first book was published.

3. Finally, in the first 30 posts in this thread I haven’t seen any mention of physiological accommodations, which is hands-down the greatest detractor to near perfect collimation! (Perfect collimation does not exist, at least to the level armchair optical engineers think/want. I have never collimated a binocular to “perfection.” And, if I did it was only to last for minutes as temperature and humidity allowed it to be so for those few minutes.

4. The most hated man is the one who tells the truth—Plato

Cheers,

Bill

PS I have been asked, more than once to post my whole article on SPATIAL and DIOPTRIC accommodation. So, here ya go.
PPS Oops! I left out the last page; it has now been added it.

 

[William Lewis]

Hi James.

Have you looked up at the stars with the diopter set for your eyes (i.e not blurring one star to oblivion) and seen if there is one crisp star or 2 stars where there should be one?

Your eyes/brain will do a lot of work to make sense of an image presented with misaligned binoculars when it's something regularly viewed so it seems ok, but the stars are a different beast. Also as rg548 and hermann say if they seem out of whack they are probably out of whack!

Merry Christmas to you too Bill! This should be ironed out in a jiffy now.

 

[Trinovid]

And I tried his method, and reported the results.

It was just a little humorous to see you asking for what was written in the preceding post.

 

[tenex]

I have always been astonished at the amount of attention devoted to collimation on this forum, given that over the course of 50+ years of use I have never once encountered a binocular that seemed out of collimation. (I've even felt eager to notice and point it out to someone, but never had the opportunity.) Of course I don't engage in front-line combat, but few here do, and even when my wife fell on top of our BN 32s they didn't appear to have been knocked out of collimation, only the diopter adjustment got decalibrated. (Don't worry, she was fine too.) Achieving and maintaining a good degree of collimation really doesn't seem to be very difficult at least among high-quality manufacturers, so I do wonder what all the fuss is about.

I said "seem" and "appear" because it's all a matter of degree, so I may actually be accommodating to a tiny degree of misalignment in some (many?) instruments. But if it causes no noticeable discomfort even in extended use, does it matter? Could such a small amount still degrade the view in any noticeable way, like perceived sharpness?

 

[Binastro]

I have had dozens of binoculars out of collimation.

Admittedly expensive binoculars seem to keep collimation very well, but even so called indestructible military binoculars sometimes go out of collimation.

As to buying secondhand there is a good chance medium priced binoculars are out of collimation.

This topic is discussed here, because the main faults with binoculars are haze, moisture, fungus and collimation faults.
Even binoculars bought from repairers are sometimes out of collimation.

As for me, I just write off faulty binoculars and don't waste time and energy getting them sorted.

Binoculars in the £1,000 class are probably in collimation unless they are seriously knocked.

If you have had no binocular out of collimation you are very lucky.

The micro Japanese binoculars in silver or silver/black are usually out of collimation.

The Chinese cheap 15x70s are likely to be out of collimation new in the box or after short use.

Soviet binoculars usually keep collimation.

Regards,
B.

 

[Rg548]

But if it causes no noticeable discomfort even in extended use, does it matter?

No it doesn't. If you can't notice it then there's nothing to complain about.
My FL8x56's were perceived ok by the previous owner, (a member on here), and also by Ace Optics.
To my eyes they were fractionally out..... and I was proved to be correct when I sent them to East Coast Optics.
Collimation is 'a thing' or we wouldn't have machines to collimate binoculars.
Some notice it more than others, just like CA.... I don't think I am too affected by CA, because I love Ultravids..... which to some people on here, are the devils own optics where CA is concerned!!!!
But I can spot a pair of bins that need collimating everytime without fail.

 

[Maljunulo]

But I can spot a pair of bins that need collimating everytime without fail.

That is a very interesting talent.

 

[Rg548]

That is a very interesting talent.

Not at all!!
I look through them, if my eyes feel un relaxed, twisted/strained.... then they are out.
Without wishing to sound arrogant, I have yet to be wrong with any pair I have sent for checking.
But some I have had, as previously mentioned, have been spot on, namely Conquest, and Se's, and my current BN's, as well as my first BN's.

 

[Patudo]

@Rg548 - You're welcome to try my binoculars if you happen to be passing by Central London and have the time - although on the one hand ignorance is bliss, it would be useful (I suppose) to know if any are out!

I, personally, haven't noticed any of my purchases being out, even though the blurb for one specifically mentioned being out of alignment. But the ones I sent in for other issues would have been checked for collimation (I assume so anyway...?) and corrected. One that I sent in was definitely out, according to Richard B - some way out at that - but I didn't really notice anything amiss. I vaguely recall Richard telling me that a barrel out of collimation in one plane (horizontal?) may be easier for the brain to accommodate for than vertical?

I haven't had any of my binoculars go out of collimation (that I could perceive anyway) except one that I dropped. But then I don't subject my binoculars to really heavy use either.

I'd say 90% plus of the "attention devoted to collimation on this forum" is attributable to one individual.