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BillC
on a new path


Reged: 06/04/04
Posts: 4391
Loc: Lake Stevens, WA, USA
Binocular Collimation
      #1833245 - 09/10/07 08:44 PM

Binocular Collimation

In more than three years on Cloudy Nights, I have never proposed to write an official “article” for the group. However, I am incessantly reminded that there are many misconceptions concerning collimation that just keep cropping up which are as wrong today as they were when they were conceived, and I would like to add my two cents worth to the subject.

1) The word “perfect” and “collimation” do not belong in the same sentence.


2) Alignment that is within the original JTII standards can be considered to function as “perfect” in that the eyes can easily accommodate the error without introducing noticeable eyestrain. For example, an 8 power instrument should have errors equal to or less than 4’ Step, 10’ Divergence and 6’ convergence, with a 16 power having 2’, 6’ and 3’ respectively.


3) Some people profess to able to “eyeball” collimation. A few of us can get within industry standards at a GIVEN IPD. This has been accepted as being called “conditional alignment” where the alignment is based on the performance of the instrument at one, AND ONLY ONE, IPD (Interpupillary Distance). HOWEVER, we can’t do it all the time based on a number of varying biological conditions. And, if you can’t duplicate human performance, the validity of the test must be called into question.

Two or three times a day, I see people who say their binocular is “perfect,” “just fine,” “good enough for me,” or the like when, in fact, it might deviate from maximum allowable error by THREE OR MORE DEGREES—not minutes, DEGREES! Are they really seeing fine? Perhaps. BUT, if they are, they are causing eyestrain. Old wives tales notwithstanding, you can’t have it both ways.

4) Collimation is collimation is collimation. A binocular is either collimated or it is not. Some folks talk about the collimation of the “tubes” or “barrels” as if that condition is somehow separate from the alignment of the optical system. While it does give folks something to talk about (and worry about) it has little to do with collimation. It would only be important IF THE TUBES WERE OUT OF ALIGNMENT WITH THE AXLE SO MUCH THAT COLLIMATION CONVENTIONS—ECCENTRIC RINGS OR SET SCREWS--WOULD NOT HAVE ENOUGH MOTION TO BRING THE INSTRUMENT INTO ALIGNMENT. If you could find a way to have one telescope pointed toward Texas and the other pointed at London, with the optics themselves being collimated, then the BINOCULAR would be collimated.

5) Some people profess that they can tell whether a binocular in collimated by looking through it backwards—one scope at a time. In a sense this is correct. However, it will usually produce useless information. If the binocular is so far out of alignment that it can be seen with this method, it is far enough out to be seen looking through it correctly.

This method may be easily used to see which telescope (meaning the optical train) is out of alignment the most. Thus, if one is planning to perform only a conditional alignment, it would be a good place to start. REMEMBER: for a given IPD, conditional alignment is the same as “collimation.”

Then what is the difference?

CONDITIONAL ALIGNMENT can be eyeballed by most people under varying conditions as long as alignment at one IPD is all that’s required.

COLLIMATION: In true collimation, alignment is within a prescribed minimum standard at ALL IPD settings. In this realm, there is no security in numbers; if 500 people talk about how they have just collimated their binoculars, then 500 people are wrong. I could certainly agree they have aligned the instrument to make it acceptable for themselves, but “collimated” . . . no.

6) Finally, many people try to help newbies figure out whether or not their binoculars are aligned by asking them to see if they notice that they have overlapping fields of view or “overlapping circles.” Well, this is only PARTIALLY correct and as often as not causes people to worry about their binoculars, or, worse than that, causes them to start tweaking with an instrument that are already within industry standards for collimation.

If one is looking at a distant OBJECT and notices—with peripheral vision—that the fields overlap, then a collimation error is present.

More often than not, the uninitiated will LOOK for collimation error by concentrating on the “circles.” When they do this, they are focusing INSIDE the binocular. And what happens when you focus on something that close? You have to cross your eyes. And what happens when you cross your eyes? You start seeing double? And what do you THINK is wrong when you start seeing double? You think the binocular is out of alignment . . . when, in fact, YOU are!

Cheers,

Bill

Edited by EdZ (11/05/07 03:09 PM)


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pcad
Carpal Tunnel


Reged: 01/17/05
Posts: 2447
Loc: Connecticut
Re: Binocular Collimation new [Re: BillC]
      #1833408 - 09/10/07 09:51 PM

Hi Bill,

The crossing of the eyes when attempting to see up close is called the synkinetic near reflex. Very important for reading, not desirable for viewing distant objects. I suspect you already know this term. I mention it since most of us haven't heard of it and it's a great word/description for what happens. The eyes move (in) together, synkinetic.

Thanks for an excellent post. Hope it gets included in the best of thread.

Peter

--------------------
Peter

Telescopes 25 - 318 mm
Binoculars 12 - 100 mm
Microscope 50x - 1000x

Edited by pcad (09/10/07 10:11 PM)


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BillC
on a new path


Reged: 06/04/04
Posts: 4391
Loc: Lake Stevens, WA, USA
Re: Binocular Collimation new [Re: pcad]
      #1833646 - 09/10/07 11:44 PM

If I said I hadn't heard of it, it would be bad for my snotball reputation. So, I won't SAY it. Ahum!

Cheers,

Bill

--------------------
William J. Cook, Chief Opticalman, USNR-Ret.
Ophthalmic Tech, Naval Station, Everett, WA
Optical Mechanic, Puget Sound Naval Shipyard
Founder, Amateur Telescope Making Journal
21-year Mgr., Optics Dept., Captain's Nautical Supplies
Optics Mechanic, Ft. Lewis, WA.
Contributing Editor for Numerous Magazines

It's better to be a "has been" than a "never was." But only barely; the pay is about the same!


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johnno
scholastic sledgehammer


Reged: 05/03/04
Posts: 807
Re: Binocular Collimation new [Re: BillC]
      #1834144 - 09/11/07 09:57 AM

Hi Bill,

Thanks for a very interesting,and informative read.

Certainly quite a bit of thought,and effort,went into it.

Regards.
John


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Falcon Birder
super member


Reged: 04/16/07
Posts: 111
Re: Binocular Collimation new [Re: johnno]
      #1835170 - 09/11/07 06:25 PM

thanks for the information. so I am wondering how professional opticalman like you do the collimation. Do you use special optical bench and test reticle to perform the testing.

--------------------
Zen-Ray SUMMIT 10x42 WP
Swaroski 8.5x42 EL
Leica 8x32 Ultravid


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eklf
Pooh-Bah


Reged: 05/12/07
Posts: 1207
Loc: Carrboro, NC
Re: Binocular Collimation new [Re: Falcon Birder]
      #1835178 - 09/11/07 06:29 PM

BillC,

Thank you very much for this great article.

You have covered many, if not all these points, throughout your posts in ths forum. But (for a novice and newbei) its great to have it all in one post.

Kumar

--------------------
Clear Skies/Kumar


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BillC
on a new path


Reged: 06/04/04
Posts: 4391
Loc: Lake Stevens, WA, USA
Re: Binocular Collimation new [Re: eklf]
      #1835263 - 09/11/07 07:12 PM

NO, thank you.

Of course, you are right. I have addressed some of these things many times. However, having the posts scattered all over CN makes it very hard for folks to find the right things to ignore. This way, having everything under one roof, so to speak, I’ve made it much easier to be ignored all at once.

I’m a full-service curmudgeon.

Cheers,

Bill

--------------------
William J. Cook, Chief Opticalman, USNR-Ret.
Ophthalmic Tech, Naval Station, Everett, WA
Optical Mechanic, Puget Sound Naval Shipyard
Founder, Amateur Telescope Making Journal
21-year Mgr., Optics Dept., Captain's Nautical Supplies
Optics Mechanic, Ft. Lewis, WA.
Contributing Editor for Numerous Magazines

It's better to be a "has been" than a "never was." But only barely; the pay is about the same!


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werewolf6977
Lord High Smasher


Reged: 12/15/03
Posts: 9034
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Re: Binocular Collimation new [Re: BillC]
      #1835984 - 09/12/07 04:44 AM

All I can say is: The. Man. Speaks.

--------------------
Pete
6" Apogee/LXD55
Starhopper 6" Dob
Spaceprobe 130EQ
Black C8 OTA
WO Zenith Star 66 Patriot Edition
Sun Pak Pro 7500 Platinum Edition
8X42 Bushnell H2O Porro
7X35 Tasco
10X50 Nikon Actions (Type 7)
15X70 Skymasters
Dell Inspiron Dual Core 531s
"For those who fought for it, Freedom has a flavor the protected will never know"


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BillC
on a new path


Reged: 06/04/04
Posts: 4391
Loc: Lake Stevens, WA, USA
Re: Binocular Collimation new [Re: Falcon Birder]
      #1854038 - 09/20/07 01:13 PM

Quote:

thanks for the information. so I am wondering how professional opticalman like you do the collimation. Do you use special optical bench and test reticle to perform the testing.




Please forgive me; I lost track of your post.

We have 2 Navy Mk5 collimators and 1 Fujinon UBMM (Expensive name for a collimator).

Cheers,

Bill

--------------------
William J. Cook, Chief Opticalman, USNR-Ret.
Ophthalmic Tech, Naval Station, Everett, WA
Optical Mechanic, Puget Sound Naval Shipyard
Founder, Amateur Telescope Making Journal
21-year Mgr., Optics Dept., Captain's Nautical Supplies
Optics Mechanic, Ft. Lewis, WA.
Contributing Editor for Numerous Magazines

It's better to be a "has been" than a "never was." But only barely; the pay is about the same!


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Gordon Rayner
Carpal Tunnel


Reged: 03/24/07
Posts: 2175
Re: Binocular Collimation new [Re: BillC]
      #1856958 - 09/21/07 05:54 PM

I looked at surplus for a long time, and only once saw a Mk.5, which was withdrawn. Yet there seem to be a number of them out there, "surplus". I recall at least three locally, several in Arizona, Cory Suddarth has one, etc. I never saw any of the auxiliary scopes in offical channels, but there was a large lot of the small rhomboids( also see Hanna in ATM III), about seven years ago. I was not high bidder, but bought several from him.
Were some tenders sold intact to shipbreakers? That does not seem credible. What happened to the Long Beach and Mare Island shipyard shops? My Mk 13 came from Mare Island I believe, but I cannot be sure, and my source is dead.Have you put a window over a Mk 5, perpendicular to the target, and then picked up the beams post-binocular in a small scope for comparison? That would be useful for swinging on the window(or not swinging) if the hinge is inaccessible.
Oh, I did buy a UBMM surplus( official surplus), but never used it.


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Claudio
sage


Reged: 07/26/04
Posts: 277
Re: Binocular Collimation new [Re: Gordon Rayner]
      #1857856 - 09/22/07 01:18 AM

Quote:

Have you put a window over a Mk 5, perpendicular to the target, and then picked up the beams post-binocular in a small scope for comparison? That would be useful for swinging on the window(or not swinging) if the hinge is inaccessible.




Hello Gordon,
could you explain more diffusely this point?

Quote:

Oh, I did buy a UBMM surplus( official surplus), but never used it.




I think I know why, but anyway: Why?

Regards
Claudio


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Gordon Rayner
Carpal Tunnel


Reged: 03/24/07
Posts: 2175
Re: Binocular Collimation new [Re: Claudio]
      #1863681 - 09/24/07 11:26 PM

Thank you for your interest, Claudio. I have just finished a post which answers your first request. It follows your post in the "Question for Bill Cook" thread.

In different words, by placing a window perpendicular to the line of sight of the target collimator, or nearly perpendicular, one can wiggle the binocular front on the window. After passing through the binocular, the two beams then enter a telescope of short focus and at least 80mm. aperture. The observer can view the focused images of the target on a groundglass or sandpapered plastic in the focal plane of the small telescope. There are three images: the direct image, and the two images through the binocular. The wiggling makes small imaginary isosceles triangles, whose included angles are the wiggle angle, and whose(mentally visualized) apexes are the hinge, If the window is truly perpendicular to the the target center line of sight, and the front of the binocular is truly perpendicular to the hinge axis, then the direct image of the target center(formed by rays which did not pass through the binocular) is at the same position on the groundglass as are the two apexes of the mentally visualized wiggle triangles. The UBMM uses a mirror as the objective of the target collimator, and flat mirrors to fold the light path.

The MK. 5 uses a large, 10 inch or 12 inch lens of about f/4, (which would not perform as a normal telescope because of very poor color correction) working in green or (?) yellow light, as the target collimator. It has no wiggle window. It has a rigid, but adjustable around two angular axes, fixture to hold the binocular. The operator forms mental isosceles (not the Navy books' "equilateral"), triangles with the aid of a small 3x or so telescope which views through one barrel of the binocular. An image of the target as seen directly, (not through the binocular half) is superimposed on the image through the binocular. It comes in via a small rhomboid prism attached to the front of the 3x auxiliary scope. A 5x20 golf scope(reticle not used) and a JTII comparator or other comparator can substitute for the now antique (typically 1920's ) Navy auxiliary scopes and rhomboids.
One could use the target collimator portion of the Mk. 5, with a wiggle window over its exit, as the first , pre-binocular portion of a UBMM-like setup.

As Hanna ponted out in ATM III, there are many possibilities. Today, there are many more, with LED essentially point sources, green lasers, and widely available low cost telescopes( a target collimator can use much lower quality optics than its reversed version, used as a normal telescope, would require).

If one can be satisfied with collimation of a hinged binocular at one and only one interpupillary distance, the scheme shown in the Army manuals( for prism squaring in that context), and repeated in the Truman Henson book "Binoculars , Rifle Scopes, ...." or something like that ( Amazon it or Google it) , which is a machinist's layout/inspection surface gage with an attached weapon sight or a 5 x 20 golf scope(use the reticle. You can also measure errors with that reticle, by converting linear to angular units) is recommended. A distant target, if available, will serve as a natural target collimator.


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Gordon Rayner
Carpal Tunnel


Reged: 03/24/07
Posts: 2175
Re: Binocular Collimation new [Re: Gordon Rayner]
      #1863737 - 09/24/07 11:46 PM

Claudio asked why I sold my UBMM Fuji Photo Optical Universal Binocular Measuring Machine.

I sold it because it is not really "universal". Nor was I doing production or semi-production. I was crowded for space. My own interests were in equipment too large for a UBMM. I had a Navy-like horizontal setup for handhelds. I was preoccupied with non-binocular and non-optical things. And, I had a opportunity to make a substantial profit. I could see that an equivalent could be assembled quickly, though perhaps not as compactly, without several folding flat mirrors .


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jkevn
sage


Reged: 03/02/06
Posts: 213
Loc: Tucson, Arizona
Re: Binocular Collimation new [Re: BillC]
      #2313888 - 04/08/08 06:32 PM

Bill,

This is very interesting article that you wrote last year, that I just ran across.

One observation: I notice that on several pairs of binoculars I've tried, the edges of the circles tend to be matched on the left side, but not the lower right side, if I look at the edge of the circle on the right side. If I look straight ahead at a distant object, the images seem well matched in peripheral vision. I am guessing that this is because my eyes are different--my left eye has nearly perfect distance vision, but my right eye is a little near sighted. Is this correct? Or is it simply an effect of how my eye coordination works?

How often are binoculars actually used to look near the edge of the field of view, with both eyes? Is this taken into consideration during binocular alignment? (I would think this would only be done with the binoculars mounted on a tripod.)

thanks, Kevin


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BillC
on a new path


Reged: 06/04/04
Posts: 4391
Loc: Lake Stevens, WA, USA
Re: Binocular Collimation new [Re: jkevn]
      #2318768 - 04/10/08 11:53 PM

Granddaughter im Burn Trama Center; more when I can.

Bill

--------------------
William J. Cook, Chief Opticalman, USNR-Ret.
Ophthalmic Tech, Naval Station, Everett, WA
Optical Mechanic, Puget Sound Naval Shipyard
Founder, Amateur Telescope Making Journal
21-year Mgr., Optics Dept., Captain's Nautical Supplies
Optics Mechanic, Ft. Lewis, WA.
Contributing Editor for Numerous Magazines

It's better to be a "has been" than a "never was." But only barely; the pay is about the same!


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Rafael
member


Reged: 09/21/06
Posts: 60
Loc: Madrid (Spain)
Re: Binocular Collimation new [Re: BillC]
      #2318948 - 04/11/08 03:22 AM

Hello Kevin.

The observed fields are determined by the field stop of the eyepieces. They must be perfectly centred on the optical axes. So, in a perfectly collimated bino, the observed fields may not be matched if the field stops are not centred.

Kind regards
Rafael

--------------------
http://sites.google.com/site/rchamon/home
Nikon 7x50 IF HP WP Tropical
Nikon 8x30 E
Nikon 8x40 Action VII
Nikon 12x40 CF WF
Nikon 7x35 Sporting
Nikon 7x20 Travelite III
Pentax 8x30 BIF Marine
Pentax 8x40 PCF III
Carl Zeiss Jena Jenoptem 7x50 WF
Carl Zeiss Jena Jenoptem 8x30 WF

Edited by Rafael (04/11/08 03:42 AM)


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Mark9473
Postmaster


Reged: 07/21/05
Posts: 6459
Loc: 51°N 4°E
Re: Binocular Collimation new [Re: BillC]
      #2320125 - 04/11/08 04:56 PM

BillC, I hope everything turns out OK. You have our thoughts.

--------------------
Mark
Leica 8x20; Nikon 7x35; Vixen 8x42; Orion 15x63; Docter 15x60
WO Megrez II 80 FD / APM 107mm f/6.5 / Mewlon 210 on DM-6 + Berlebach Planet


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GlenM
Vendor - Lyra Optic


Reged: 05/20/07
Posts: 2549
Loc: Lancashire England
Re: Binocular Collimation new [Re: BillC]
      #2320194 - 04/11/08 05:23 PM

My thoughts are with you and the family at this difficult time Bill.

--------------------
Glen

www.lyraoptic.co.uk


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hallelujah
Post Laureate


Reged: 07/14/06
Posts: 3980
Loc: Colorado Rocky Mountains
Re: Binocular Collimation new [Re: GlenM]
      #2320205 - 04/11/08 05:28 PM

My wife and I will be praying for your granddaughter.

--------------------
Nikon7x35GoldSentinel 9.3*(2)+Pentax8x40PCFWPII+MinoxBD10x44BP+FujinonFMTRSX7x50
Nikon10x50GoldSentinel+Pentax12x50 5.5*Japan+Pentax12x50PCFWPII+Vixen8x56Geoma
Fujinon12x60HB+Pentax16x60PCFWP+Pentax20x60PCFWP+Pentax20x60PCFWPII
Tento20x60USSR+Orion12x63MiniGiant+Spectrum I 20x65+Orion15x70LittleGiant II
Orion20x70LittleGiant II+Orion16x80Giant+Orion30x80MEGAView+Barska30x80X-Trail
BurgessOptical20x90SeriesII


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jkevn
sage


Reged: 03/02/06
Posts: 213
Loc: Tucson, Arizona
Re: Binocular Collimation new [Re: GlenM]
      #2321033 - 04/11/08 11:55 PM

Bill, I'm sorry to hear that. I hope things turn out OK. Kevin

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