diopter mechanisms - why all the complexity? (1 Viewer)

[henry link]

I think it's possible that center hinge diopter adjustment has largely been imposed on modern roof prism binoculars by the collimation method required for internal focus designs. I believe all the current alpha roof prism binoculars use rotating eccentrically mounted eyepieces for collimation. Obviously a rotating ocular can't be used for diopter adjustment in binoculars that are collimated with eccentrically mounted oculars.

Eccentric objective collimation is probably not desirable in such binoculars because the internal focusing lenses are part of the objective group. If the fixed objective elements are moved laterally they'll become de-centered from the focusing lens.

 

[Pinewood]

I don't understand the grousing over a proven design that has existed on Zeiss binoculars [in a slightly altered form] for decades, and [as far as I know] has not produced any problems for users and [should] produce a far more stable setting than any ocular or combo. focus design.

Hello James,

My only complaint about the focussing mechanism on the Zeiss FL, not on the 7x32 ClassiC, is that it can be moved from the lock position when it is removed from a bag. My solution is that I try to be careful or just never use a bag.

Happy bird watching,
Arthur

 

[dalat]

Leicas diopter mechanism is clearly the best. No other is so relaxing to use and so precise. But I agree, it's a not really needed luxury, adjusting diopter is just not something I do on a daily basis. I can handle the more painful fiddling around of lesser mechanisms (like Zeiss FL, or classical Porros) for the few times I need to adjust or check dipter setting.

However, I also wondered if integrating the dioper adjustment in the central focus might actually be the more simple and elegant technical solution? After all, its here where focussing is happening, so feels kind of logic to integrate the dipter setting here. Diopter adjustment on a barrel requires adding another mechanism, that might bring it's own problems, e.g. with sealing (or the things mentionned by Henry)... Well, I've not much clues about binocular mechanics, so that's just a laymans guess...

 

[A2GG]

I'm mechanically challenged and never felt that adjusting the diopter was
complex. I found it annoying due to vision problems, but never complex.
It's so simple a caveman can do it. . I prefered the center diopter when I had
my Leupold 7x42.

 

[peatmoss]

For those who like to have it both ways... the Steiner Wildlife Pro 8x30 CF has center focus, plus individual diopter controls on both eyepieces.

 

[kabsetz]

I think it's possible that center hinge diopter adjustment has largely been imposed on modern roof prism binoculars by the collimation method required for internal focus designs. I believe all the current alpha roof prism binoculars use rotating eccentrically mounted eyepieces for collimation. Obviously a rotating ocular can't be used for diopter adjustment in binoculars that are collimated with eccentrically mounted oculars.

Eccentric objective collimation is probably not desirable in such binoculars because the internal focusing lenses are part of the objective group. If the fixed objective elements are moved laterally they'll become de-centered from the focusing lens.

Henry,

These are excellent points, and clearly there is a certain elegant simplicity about the center hinge diopter adjustment, as in these it is just a deliberate adjustable offset between the left and right focusing lenses that is used, and everything happens internally.

But, I'm not sure that eccentrically mounted oculars would exclude the possibility of incorporating a diopter adjustment into one of the eyepieces. I can imagine several ways in which this could be done. Do you happen to know how collimation is achieved in roofs such as Nikon's HG/L series or Zeiss Conquest HD's which have the "old-fashioned" diopter setting with a ring around the right ocular. I'm assuming that these move a lens between the eyepiece proper and the prism to adjust diopter. If such a binocular had eccentrically mounted ocular collimation, the diopter adjustment lens would ideally need to be part of the assembly that moved when collimating.

Kimmo

 

[hinnark]

Kimmo,

with Nikon HG and almost all other Japanese and Chinese roof prism binoculars with internal focusing the diopter setting works as external focusing. You can see how the lens/eyepiece at the barrel where the setting is located moves forth and back while turning the focusing ring in one or the other direction. I think in principle this works like the classical diopter settings we know from so many porro bins. But it isn't as obvious because the movement of the single EP happens within the barrel. Some call this type of solution "untrue internal focusing". At least in theory this solution is inferior in respect of waterproofness compared to "true or complete internal focusing". The only binoculars I actually recall coming from Asia that have true internal focusing are the Nikon EDG. Another exception are the Nikon pocket bins of the HG(-L) series which do have true internal focusing, too.

I like the classical placement of the diopter setting at the barrel where the effect happens for reasons I would call "logical ergonomic" or operating logic. However, the diopter setting with e.g. a Leica is so easy and perfect, that I hardly miss the better operating logic of the classical solution.

Steve

 

[Troubador]

adjusting the diopter
It's so simple a caveman can do it.

So, Beth, you have been 'associating' with cavemen have you ? o

Lee

 

[iveljay]

Get an old pair of porros with a well worn focussing mechanism and press your left or right eye firmly against the corresponding eyepiece, instant dioptre correction.

A more serious point is why are people worried about this - most of my bins are pretty well perfect at -0.5 on my right eye, other than a Nikon and Minox but I set up the dioptre when purchased and rarely touch them after that.

Do other folks eyes change from day to day?

My vote for the most irritating is on a pair of Pentax 12x24 UCFs, where the dioptre knob pops out of the centre of the focussing knob at the slightest provocation, its not a problem, but just extremely annoying. Even a Minolta UC 8x18 is more practical than that! Fortunately it is only rarely used.

 

[henry link]

Henry,

These are excellent points, and clearly there is a certain elegant simplicity about the center hinge diopter adjustment, as in these it is just a deliberate adjustable offset between the left and right focusing lenses that is used, and everything happens internally.

But, I'm not sure that eccentrically mounted oculars would exclude the possibility of incorporating a diopter adjustment into one of the eyepieces. I can imagine several ways in which this could be done. Do you happen to know how collimation is achieved in roofs such as Nikon's HG/L series or Zeiss Conquest HD's which have the "old-fashioned" diopter setting with a ring around the right ocular. I'm assuming that these move a lens between the eyepiece proper and the prism to adjust diopter. If such a binocular had eccentrically mounted ocular collimation, the diopter adjustment lens would ideally need to be part of the assembly that moved when collimating.

Kimmo

Hi Kimmo,

Yes, on further reflection I think it would be possible. Let me do a little research on the HG/L. I have a friend with a 10x42 and cutaway images of both the right and left oculars. A quick look doesn't reveal how they work. I'll post the cutaways later today.

Henry

 

[bentleyg]

Have to admit that the focussing knob on my Swaro ELs occaisional pops up and I find myself only focusing on one barrel. I don't need any compensation so just have to hurredly set it back to 0 and pop it home again but it's irritating.

 

[John Dracon]

Henry has raised an interesting point about the possible connection between the diopter located on the center knob and collimation issues. I know nothing about how roofs are recollimated. Porros I do. Perhaps the recollimation of roofs would make for an informative new thread.

John

 

[bentleyg]

When I was younger and could only afford used equipment I recollimated an early pair of roofs (can't remember the make). It was done with little screws mounting the prisms using jeweller's screwdrivers and was quite tricky. I just fiddled with them till the double vision went. I used then for about a year before trading in for some new Swift Audobon's

 

[A2GG]

So, Beth, you have been 'associating' with cavemen have you ? o

Lee

Some of my best friends are Cavemen.

 

[Alexis Powell]

I thought that it was Leica that was the leader in this area--smooth as silk diopter control for left and right sides from the center drive that locks firmly, introduced with the Ultra Trinovid BA in ~1988 and continued unchanged to today's Ultravid HD. I don't think the design has any deficiencies despite its complexity, and I don't think any other design, simple or complex, has matched or surpassed it.

--AP

I think another reason I like the Leica is that I prefer to set diopter with both eyes open. The independent left and right sides makes it very easy to find the point where both eyes are most relaxed. My left eye is dominant, so it is especially awkward to do this with bins with a right side diopter control.

Truth be told, the most important feature in a diopter adjuster for me is that it stay put once set. I don't share my bins and I always wear my glasses, so I don't set the diopter very often. I prefer bins that are properly calibrated at the factory so the "zero" setting is true zero. Some of the cheap Chinese roofs are way off, so once the right side is adjusted, the position of the ocular lens relative to the eye cup can be way different from the (fixed) left side, thus providing different eye-relief on the two sides! This wasn't a problem in old porros that used basically same system of ocular movement because the eyecup moved in and out with the optics.

--AP

 

[John S.]

I think the HT diopter is actually simple, far more simple than the combo. focus on the FL/EL/EDG and harkens back to ''old school'' Zeiss style, when the dioptre was on the end hinge centre.

The HT diopter is a simple non-locking twist and turn dial, I can't see anyone having any problem figuring it out. It doesn't move, it is out of the way and doesn't get bumped accidentally like a right hand ocular diopter and [best of all] you can see the setting everytime you raise the bin to your eyes and you can easily make changes if need be. I can't think of a more logical and ergonomic diopter placement and design.

Yes, I agree completely. It does away with the need for locking or click diopters and is easier to adjust when trying to keep the binoculars aligned with ones eyes. Difficult to adapt to the beloved porro prism design.

 

[Troubador]

Some of my best friends are Cavemen.

Lucky old cavemen B

L

 

[henry link]

Henry,

These are excellent points, and clearly there is a certain elegant simplicity about the center hinge diopter adjustment, as in these it is just a deliberate adjustable offset between the left and right focusing lenses that is used, and everything happens internally.

But, I'm not sure that eccentrically mounted oculars would exclude the possibility of incorporating a diopter adjustment into one of the eyepieces. I can imagine several ways in which this could be done. Do you happen to know how collimation is achieved in roofs such as Nikon's HG/L series or Zeiss Conquest HD's which have the "old-fashioned" diopter setting with a ring around the right ocular. I'm assuming that these move a lens between the eyepiece proper and the prism to adjust diopter. If such a binocular had eccentrically mounted ocular collimation, the diopter adjustment lens would ideally need to be part of the assembly that moved when collimating.

Kimmo

Kimmo,

I finally got around to looking at the diopter adjustment on my friend's 10x42 HG/L. It's not at all clear how it works from looking at internal views, but on his binocular I could see that turning the diopter ring on the right ocular causes the cylinder containing all the eyepiece elements to move back and forth without rotating, so, you're right, it is possible to use an eyepiece mounted diopter ring and still collimate with eccentrically mounted eyepiece optics.

One oddity about the Nikon system is that the outer eyepiece housing and eye-cup don't move along with the inner cylinder containing the eyepiece lenses, so a diopter adjustment requires a compensating teak to the eyecup length.

Henry