Focus Direction (1 Viewer)

Is there an explanation for why a manufacturer would make a binocular focus to infinity in the counter clockwise direction. Most of all my glass that goes back to the 50s focus to infinity in the clockwise direction. At first I thought it was a mistake, but later found it was not.

Andy W.

It's an issue for camera lenses two. You have focus direction, zoom direction, and aperture ring direction to worry about. Even in some compatible lens designs (micro 4/3), the zoom directions can be opposite, though the focus direction can be set in a menus as its fly-by-wire. Nikon and Pentax all went one way (clockwise to infinity) and Canon and Olympus went the other way. Sony split the difference and focus went one way and zoom went the other. Though I think some sony lenses focus in opposite directions. 3rd party lenses often focus the same direction as the native brand, but some only go one way regardless of the host camera mount, so it could be opposite the native glass. It used to be a big deal, but nowadays most people do not touch to the lens except to zoom. Hopefully I got all those directions the right way.

Personally, I'm a clockwise to infinity user and have returned some binoculars because they focus the "wrong way."

AFAIK, the directions are a brand thing and there's no technical reason for one way or another. But I'd be interested in hearing if there were!

Marc

It seems most if not all alpha binos focus clockwise but in middle-priced binos it could be 50:50 clock and anti-clock.

Lee

dries1 said:

Is there an explanation for why a manufacturer would make a binocular focus to infinity in the counter clockwise direction. Most of all my glass that goes back to the 50s focus to infinity in the clockwise direction. At first I thought it was a mistake, but later found it was not.

Andy W.

Click to expand...

191212

Hi, Andy:

Some folks bemoan my lack of succinctificatiousnessosicity. But that is because so many don’t give me a question that can be answered succinctly.

First, note that focus is focus is focus. However, getting there—AND STAYING THERE—is the problem.

Some time ago, it was determined that the best focus could be attained by focusing at infinity and slowly bringing the focus closer to the observer—stopping at the desired image along the way. If I focus my 8x32 Nikon SE at 300 yards, and then on something at the edge of my front yard—30 feet away—I turn the focus wheel counterclockwise. For anyone who understands the WHYS of the procedure, it really shouldn’t matter. Sadly, the story doesn’t end there.

I think the following, from my article on spatial and dioptric accommodations will fill in the gap for you.

DIOPTRIC ACCOMMODATION

The second accommodation of critical importance is dioptric. Spatial accommodation relates to merging lines of sight along the X and Y axes via the eye’s rectus muscles. Dioptric accommodation is achieved through the eye’s ciliary muscles, which stretch and compress the eyelenses in order to achieve a sharp focus.

A 10-year old may have as much as 14 diopters of accommodation. This was the root of Steiner’s bogus claim that their binoculars were “auto-focus.” But as we age dioptric flexibility drops off fairly quickly. By age 20, it has dropped to 8 to 10 diopters with the average binocular user—40 to 50 years of age—having only a 4-diopter accommodation. Thus, with each year that passes, the focus mechanism, becomes ever more critical.

Let’s suppose an observer is viewing an image—celestial or terrestrial—and he or she has a dioptric accommodation of 4 diopters. The brain wants to see things in focus quickly. So, involuntarily the ciliary muscles may bring things to a focus at the edge of the observer’s accommodation. But what if the observer’s natural/at rest accommodation is -1.5 diopters. Focusing at the edge of accommodation will result in eyestrain and cause the observer to continue adjusting with the focus mechanism in hopes of attaining the sharpest image.

But, without understanding the process, the observer is, more than likely, apt to follow the same procedure that caused the original problem.

Undoubtedly, your mother tried to teach you not to stare. However, if you want the sharpest image, and one that leaves your viewing fiddle free, you had better forget that advice.

Learning to stare comes easily for some people but takes practice for others. Still, learning to stare is worth the effort and is absolutely essential to attaining the sharpest image and most trouble-free focus.

I think the explanation for why at least some binoculars, particularly low to mid price ones, focus counter clockwise is that they use the less common positive focusing lens design, but for reasons of cost share basic focusing mechanism parts with other models that use the more common negative focusing lens design.

The focusing lens moves forward toward infinity focus if it's negative, but backwards if it's positive. If a focusing mechanism is designed to move clockwise toward infinity with a negative focusing lens it will have to move counter clockwise toward infinity focus if it's installed in a binocular with a positive focusing lens.

dries1 said:

Is there an explanation for why a manufacturer would make a binocular focus to infinity in the counter clockwise direction. Most of all my glass that goes back to the 50s focus to infinity in the clockwise direction. At first I thought it was a mistake, but later found it was not.

Andy W.

Click to expand...

Folks, if you used your binocular last to view the Pleiades and now want to focus on the bird in your backyard, you will turn the focus wheel in one direction. If you last focused on the birds in your backyard and now want to focus on the Pleiades, you will turn the focus wheel in the opposite direction. It’s not rocket science nor a corporate conspiracy. It’s just physics doing its thing. :cat:

Bill

Thanks for the responses, the weather is drying up from the rain now, time to get outside.

Andy W.

WJC said:

...Some folks bemoan my lack of succinctificatiousnessosicity. But that is because so many don’t give me a question that can be answered succinctly...

Click to expand...

I'll not criticize you for succinctness, but I will complain about clarity, particularly your penchant for leaving off the punch-line (i.e. making the final crucial connection or conclusion) in your cranky treatises. Also, I will point out that you are not answering the OP's question.

WJC said:

...Some time ago, it was determined that the best focus could be attained by focusing at infinity and slowly bringing the focus closer to the observer—stopping at the desired image along the way...

Click to expand...

Perhaps true, but this would be a recipe for tired eyes because they would be working hard to achieve closer focus using their own accommodation (i.e. focusing ability) before the binocular focus was adjusted the appropriate amount. Perhaps that is what you are getting at when you say

WJC said:

...Sadly, the story doesn’t end there...

Click to expand...

and go on to talk about accommodation, and the merits of "staring", but you don't connect the dots. Then, in a subsequent post you write

WJC said:

Folks, if you used your binocular last to view the Pleiades and now want to focus on the bird in your backyard, you will turn the focus wheel in one direction. If you last focused on the birds in your backyard and now want to focus on the Pleiades, you will turn the focus wheel in the opposite direction. It’s not rocket science nor a corporate conspiracy...

Click to expand...

which implies that it doesn't matter whether you achieve best focus by focusing far to near or by focusing near to far. I think, based on my own experience, that it does matter because it is more relaxing to focus near to far (since it makes the binocular do all the "work" as the eyes try to relax to achieve focus before the binocular has been adjusted the appropriate amount). Consequently, when birding, I always quickly focus in front of the bird (perhaps even before getting the bins to my eyes), then adjust outward to proper focus. I think that you agree, but it is not obvious even on a careful read of your posts (so maybe I'm wrong)!

To get back to the OP's question, I find Henry Link's explanation intriguing because I've never encountered it before. I'll have to look to see if it is consistent with bins in my collection the next time that I have them out.

I prefer clockwise-to-infinity focus, and fortunately, this standard is used in all the best models that I've ever tried. My argument for the superiority of clockwise-to-infinity focus (for right-handed users) is that one should always focus too near first, then adjust outward. I also believe it is inherently easier to pull a wheel-like knob precisely with one's finger than to push it. Consequently, if right-handed and focusing with fingers of the right hand with a clockwise bin, this first movement (to achieve a too-close setting) can be accomplished by a relatively crude push with the fingers, and then can be followed by a precise pulling adjustment to achieve perfect focus. Bins that go the other way make right-handed users (who want to final focus near-to-far to keep their eyes relaxed) achieve best focus with an inherently less precise pushing motion.

--AP

dries1 said:

Is there an explanation for why a manufacturer would make a binocular focus to infinity in the counter clockwise direction.

Click to expand...

To me that makes a lot of sense. Holding the binocular with a finger of the right hand on the focuser wheel, pushing outward shifts the focus outwards and pulling inwards pulls the focus nearer.

What about individual focus binoculars? Sorry could not help myself.

Turn right for distance.

I'm right handed and like to use the two finger focus (not to be confused with the two fingered salute or even the great Ozzie salute ! which the magnificent Zen allows - well ..... magnificently (if somewhat hysterically hysteresisical

This involves a bit of rock n roll - but I'm very particular in what I like to jive to :loveme: :cat:

I like to rock to the left and roll to the right :t: but will leave which way I swing for another day ! :cat:

Anything other than a clockwise to infinity focuser leaves me decidedly goofy footed and discombobulated ! :eek!:





Chosun :gh:

henry link said:

I think the explanation for why at least some binoculars, particularly low to mid price ones, focus counter clockwise is that they use the less common positive focusing lens design, but for reasons of cost share basic focusing mechanism parts with other models that use the more common negative focusing lens design.

The focusing lens moves forward toward infinity focus if it's negative, but backwards if it's positive. If a focusing mechanism is designed to move clockwise toward infinity with a negative focusing lens it will have to move counter clockwise toward infinity focus if it's installed in a binocular with a positive focusing lens.

Click to expand...

Perhaps it's just the reluctance of low or mid tier manufacturers to use left-hand threads in the focussing mechanisms.
There are several examples of binoculars with positive focussing elements, which focus clockwise to infinity, e.g. Zeiss SF, Meopta Meostar, Swarovski SLC (pre HD) and the original Swarovski EL (pre Swarovision).

John

Alexis Powell said:

I'll not criticize you for succinctness, but I will complain about clarity, particularly your penchant for leaving off the punch-line (i.e. making the final crucial connection or conclusion) in your cranky treatises. Also, I will point out that you are not answering the OP's question.


Perhaps true, but this would be a recipe for tired eyes because they would be working hard to achieve closer focus using their own accommodation (i.e. focusing ability) before the binocular focus was adjusted the appropriate amount. Perhaps that is what you are getting at when you say and go on to talk about accommodation, and the merits of "staring", but you don't connect the dots. Then, in a subsequent post you write which implies that it doesn't matter whether you achieve best focus by focusing far to near or by focusing near to far. I think, based on my own experience, that it does matter because it is more relaxing to focus near to far (since it makes the binocular do all the "work" as the eyes try to relax to achieve focus before the binocular has been adjusted the appropriate amount). Consequently, when birding, I always quickly focus in front of the bird (perhaps even before getting the bins to my eyes), then adjust outward to proper focus. I think that you agree, but it is not obvious even on a careful read of your posts (so maybe I'm wrong)!

To get back to the OP's question, I find Henry Link's explanation intriguing because I've never encountered it before. I'll have to look to see if it is consistent with bins in my collection the next time that I have them out.

I prefer clockwise-to-infinity focus, and fortunately, this standard is used in all the best models that I've ever tried. My argument for the superiority of clockwise-to-infinity focus (for right-handed users) is that one should always focus too near first, then adjust outward. I also believe it is inherently easier to pull a wheel-like knob precisely with one's finger than to push it. Consequently, if right-handed and focusing with fingers of the right hand with a clockwise bin, this first movement (to achieve a too-close setting) can be accomplished by a relatively crude push with the fingers, and then can be followed by a precise pulling adjustment to achieve perfect focus. Bins that go the other way make right-handed users (who want to final focus near-to-far to keep their eyes relaxed) achieve best focus with an inherently less precise pushing motion.

--AP

Click to expand...

1912012

Alexis,

I would have never figured you to be one of those “pile-on” kind of guys. But, oh well.

— I will complain about clarity, particularly your penchant for leaving off the punch-line (i.e. making the final crucial connection or conclusion) in your cranky treatises

*** Many on this forum UNDERSTAND the reason for my “cranky treatises” and support my reason for using them. You could find your definitive answer in Post #1 of “Thank You, MERRY CHRISTMAS, and Publin,” wherein I state “Of course, this will affect few members of any bino forum. But some of those errors have grown in popularity and been embellished over the years and cannot be effectively addressed with a politically correct, milquetoast approach. If the civilized approach would do the job, the curmudgeon would have never been born. But in the world of bino forums where opinion is often elevated to fact, experience has taught me that it’s necessary.”

— Also, I will point out that you are not answering the OP's question.

*** I think you will find that the OP—Andy’s question—was answered about as accurately as anyone can find on a binocular forum without burrowing into the head of a corporate leader. I have neither the time nor inclination to stack those BBs. Please ask Andy what he thinks of the situation, either on the forum or with a PM.

— Perhaps true, but this would be a recipe for tired eyes because they would be working hard to achieve closer focus using their own accommodation (i.e. focusing ability) before the binocular focus was adjusted the appropriate amount.

*** Tired eyes have NOTHING to do with it; the gospel of learning to STARE, which I have been trying to preach to all who would listen, deals with that. Many times, in scripture, a great thing is only attained with some tiny effort. But today, as anciently, some people pass by those tiny efforts and wind up paying for doing so. The prevalent thinking with a majority of manufacturers seems to be that it is better to start with an INFINITY focus and bring the focus closer to the observer. THE FACT IS, YOU HAVE TO FOCUS IN THE DIRECTION REQUIRED AND THAT MAY REQUIRE TURNING THE WHEEL EITHER WAY DEPENDING, ON THE LAST VIABLE FOCUS.

— and go on to talk about accommodation, and the merits of "staring", but you don't connect the dots. Then, in a subsequent post you write ... Folks, if you used your binocular last to view the Pleiades and now want to focus on the bird in your backyard, you will turn the focus wheel in one direction. If you last focused on the birds in your backyard and now want to focus on the Pleiades, you will turn the focus wheel in the opposite direction. It’s not rocket science nor a corporate conspiracy...

With the paragraph above, the question was answered THOROUGHLY!

— I prefer clockwise-to-infinity focus, and fortunately, this standard is used in all the best models that I've ever tried.

*** What you or I “PREFER” has NOTHING to do with the operation. The difference between the distance to the LAST USED focus, and the new one, has EVERYTHING to do with it. Attached is a similar story wherein we see PREFERENCES did not override physics. To finish on “staring,” you will find the “punchline” in post #4. Of course, if you need bragging rights, and have a penchant for making the manufacturer happy, you can start by turning the focus wheel for an INFINITY focus every time before moving in your desired target. For me, this is tantamount to wrecking the car to turn the radio off.

Finally, you have been reading too many posts from our British friends; in the United States periods AND commas go INSIDE the quotation marks as per The Chicago Manual of Style, 14th edition, pages 160 and 161. :cat:

Tringa45 said:

Perhaps it's just the reluctance of low or mid tier manufacturers to use left-hand threads in the focussing mechanisms.
There are several examples of binoculars with positive focussing elements, which focus clockwise to infinity, e.g. Zeiss SF, Meopta Meostar, Swarovski SLC (pre HD) and the original Swarovski EL (pre Swarovision).

John

Click to expand...

Hi John,

I started to mention the SF and the Swarovskis as exceptions to pattern of counterclockwise focus combined with positive focusing lenses. Since those are all high end binoculars you might expect a dedicated focuser design for each model series.

The only binocular I have now with the counterclockwise focuser/positive focusing lens combination is a very cheap "Dakota" 8x32. Can't recall a binocular that combined a counterclockwise focuser with a negative focusing lens. I'll readily admit this all is pure speculation.

Henry

Focusing to Maximise Sharpness

Picking up on Bill's first point in post #4, he notes that best focus is achieved by focusing to infinity, and then slowly focusing closer until the best focus on a subject is achieved

Those familiar with the concept of Depth of Field as used in photography will understand the reason for this:
- when a lens is focused to a specific distance, there is an area of ‘acceptable sharpness’ on either side of the specific distance, and;
- at conventional distances (i.e. excluding macro photography) the area extends approximately 1/3 in front of and 2/3 behind the point of best focus


When my binocular is focused at a distance closer than that of a new subject of interest, my standard procedure (conditioned by my experience with manual focus camera lenses) is to:
- focus through and slightly beyond clear focus on the subject, and;
- then focus back to obtain best focus

And if focusing on a bird generally facing toward me, I will often focus on the eye (a typical photographic preference) so that the area of acceptable sharpness will ideally include both:
- the beak in front of the eye, and;
- the body behind the eye
And of course I may refocus to concentrate on a specific detail


While most of my binoculars show the immediate ‘focus snap’ that Roger Vine describes in his reviews of better optics (see: http://www.scopeviews.co.uk/BinoReviews.htm ),
through long practice with manual focus camera lenses, what I’ve described above is still my preferred technique for critical focusing


John

Focus direction, this idea has been mentioned on the forum over the years.
I think it does not matter at all to me, I have used dozens of different binocular models, and
this thought is simple.

When you use a binocular, you just focus it to your liking. If you get worked up or have a big care about which
direction it focuses you have my sympathies. Your brain should be able to get it....

Jerry

Focus direction with binoculars is akin to the the position of windshield wiper and lighting controls in two different cars. They might be in the same general location, but not necessarily operate in exactly the same way. If you think about it, NONE of it is intuitive... you had to learn it.

It may be good fodder in a birdforum thread, but shouldn't be that big of a deal in real life.

Simple analogy: Look at plumbing... hot and cold water controls, in one's own home, in one's country, and then internationally...
there is no standard for how they work.

!st world whining is what's going on here. But that's what this place is for sometimes. ;-)

cheers,

-Bill

While the how one focuses (the procedure or method) is the important thing and the direction one turns the control is just how it operates, I find it unpleasant to use a binocular that focuses in the opposite direction than I am used to. It causes me delays in getting focus and sometimes I miss seeing something I wanted to see. I usually have a mental model about where I was last focused and where I am focusing next, so I know if I need to go out or in. Having a backwards control messes with that model.

While one can adjust, making it 2nd nature takes time. Back in the manual focus camera days, the number I heard was about 3 months until a good photographer focused without hesitation after changing systems to one that went the other way. Back then the photographer's brain was the autofocus system, so speed and accuracy were paramount to getting good action or sports photos. Basically the same thing as with binoculars (though more demanding on a camera I think as there's no eye accommodation).

Taking the time to go out to infinity and back is not what I would do for most viewing. I use the technique described above of going a little beyond the target and pull back to lockon the best plane of focus.

The Minox BLv2 is an example of a mid-tier (~$400 USD) model that focuses CCW to infinity.

Marc

dries1 said:

Is there an explanation for why a manufacturer would make a binocular focus to infinity in the counter clockwise direction.

Click to expand...

Hi Andy, I'm not a historian and I don't have all the legal and official information, but I think the answer to the question you're raising is to be found in the history of binoculars.
I believe that in the beginning were the IF binoculars (independent focus) and that the mechanical work of adjusting the focus adopted the right-hand screw thread, for the highest ease of machining at the lathe.
Even today the right-hand thread is used for these IF binoculars, so when we screw the eyepiece (clockwise rotation) the focus is focused towards infinity (and vice versa).

I think that the producers in history have adapted to this basic system, to then copy it also on the CF binoculars (central focus). But to maintain the clockwise rotation of the central ring nut, they had to construct the focusing pin with the left-hand screw.

For me it was a bad idea. Since it will be much more intuitive for right-handed people, that the central ring close the focus during the clockwise rotation, while moving the focus towards infinity during the counter-clockwise rotation.

But I follow the logic, the producers instead seem to follow other things.

Back in the 1970's Zeiss's recommendation was to turn the focus towards a closer distance and 'overshoot' your subject by a small amount and then refocus back towards infinity more carefully and arrive at a good sharp focus.
I have got used to this procedure partnered with clockwise focus systems. However I soon get used to anti-clock systems for normal viewing so most of the time don't find this too much of a problem, more an irritation. However, if a particularly urgent or exciting observing opportunity arises, half the time I instinctively revert back to focusing as if the focuser is a clockwise one, and as Marc points out, stuff can get missed.
I am right-handed and mostly just use my first finger to focus. I learned the directions of the clockwise focus system by telling myself 'push-in closer' (so push the top of the wheel away) and 'pull-out further' (so pull the top of the wheel towards my hand).

Lee