• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
Feel the intensity, not your equipment. Maximum image quality. Minimum weight. The new ZEISS SFL, up to 30% less weight than comparable competitors.

Let’s talk about eyecups (comfort, dimensions, preferences, etc.) (1 Viewer)

[email protected]

Well-known member
Supporter
Denco

Like custom ear plugs for professional motorcycle riders! But I believe even they are costly.

Stephen
Or like when the dentists make a night guard for your teeth to keep you from grinding them at night. They make an exact plaster cast of your teeth which fits perfectly. As Pileatus says above, though, you can use your hands cupped around your binoculars to form eye cups that conform to your face.
 

jafritten

Well-known member
The most comfortable eyecups I have on a binocular are those on the 42mm SLC. I also like the ones on the E2 very much. The most horrible ones were on the Vixen Ascot 7x50. They were like drilled out hockey pucks.
 

ragin-cajun

Well-known member
United States
I really liked the Zeiss SF but the eyecup adjustments felt plastic cheap and didn't lock with a distinctive snap compared to the NLs. is that the case or did I just test a bad pair?
 

Stephen Prower

Well-known member
JAFritten Denco

I attach three photos:

IMG_2782 Modified eyecup on 8x30 Porro 1.jpg: I acquired some thicker inner tube than usual and used it to eliminated one layer of tubing. The doubled over outer layer supplies 3mm of extension and a rounded rim to the eyecup. I think the Porro was a Yashica 8x30

IMG_1099 Opticron 8x32 SR.GA.jpg: This is an early effort that came out more tidily than I usually manage to achieve. I used a double 'roll-over' to get more than the 3mm of extension of the eyecup of the Yashica

IMG_2917 SvBony 8x32 ED - Work in progress.jpg: The photo shows a binocular fitted with wider eyecups as part of a full customisation job (In particular by the 'Work in progress' I customise the binocular with barrel extensions* so that as well as coming to the eyes with the eyes at the point of eye relief, it comes to the hands in balance). I intend to report in a future thread on the completed job.


Stephen

* The barrel extensions in the photo are in their 'Proof of concept', not final state
 

Attachments

  • IMG_1099 Opticron 8x32 SR.GA.jpg
    IMG_1099 Opticron 8x32 SR.GA.jpg
    457.2 KB · Views: 37
  • IMG_2782 Modified eyecup on 8x30 Porro 1.jpg
    IMG_2782 Modified eyecup on 8x30 Porro 1.jpg
    767.1 KB · Views: 38
  • IMG_2917 SvBony 8x32 ED - Work in progress.jpg
    IMG_2917 SvBony 8x32 ED - Work in progress.jpg
    741.3 KB · Views: 38
Last edited:

Stephen Prower

Well-known member
Could you post a photo of your modified eyecups, please? I'd really like to see them.

Cheers

JA Fritten: Don't rush to imitate me! I've been lucky with my supply of discarded inner tubes. You may not be.

For the outer layer you will probably be looking for a tube of size to fit a mountain bike tyre of 2.35 inch maximum section or thereabouts. They are getting harder to find, certainly for me in England. I have been told that it is because the sort of mountain biker who uses such 'extreme' tyres is beginning to switch to tubeless tyres.

Wllmspd posts at Post #15 of an earlier Thread on widening eyecups:


of how he gets round the difficulty.

I exploit the stretch of an intact length of inner tube. So Wllmspd's method might not work for me. I don't know how far a glued join of butyl rubber to butyl rubber would hold when stretched.


Stephen
 
Last edited:

Stephen Prower

Well-known member
JA Fritten

Some measurements

I measured up a typical job the other day to give you an example of the measurements that I use. I hope you find them of further help. I attach a photo.

Inner sleeve:

I fitted the inner sleeve over the 10mm high adjustable eyecup of the Swift, as set in the 'Up' position.

I cut a 10mm length of thick (1mm) bicycle inner tube as supplied to fit a 16 inch diameter tyre of 2.125 inch maximum section.

I did not try to freeze the eyecups in the Up position because the eyecups of the Swift are screw-up eyecups, and hold the Up position well.

I don't know anything about BMX bikes. But the inner tube could be intended for the tyre of a BMX bike. The tube might also have been intended for a childrens' bike, but the thickness suggests that it was particularly intended for a bike that would be heavily used.

Doubled over outer sleeve fitted over inner sleeve over eyecup:

I cut a 25 mm length of ordinary bicycle inner tube as supplied to fit a 29 inch diameter tyre of 2.30 inch maximum section for the doubled-over outer sleeve.

A length of 25mm is more than twice the 10mm height of the eyecups. I judged by experience that I would need an extra 5mm, part to allow 1mm* for roll-over, and part to increase the height of the eyecups by my desired figure of 2mm.

Wings:

I used ready-cut wings, and forgot to note the depth of the collar, but the depth would obviously have been 10mm, the same as the depth of the eyecups.

The loft of the wings is 10mm. I think I may have said before that, subjectively, I find a 10mm loft on other binoculars to be useful to cut out a portion of side-light, and largely to block out peripheral vision.

Result (Width of eyecups):

The original external width** of the eyecups of the Swift was 30mm. The width that I achieved by my customisation was 39mm, or 40mm if I include the wings***.

Result (Extension of eyecups):

I deliberately select the section of the inner tube that I use to be a little narrow for the job so that it stretches a bit. The stretch clamps the tube in position, and gives a comfortable roll-over edge to the eyecup.

Nevertheless, even though inner tube may be stretched, it may still slip a bit.

So precise measurement of the length of the inner tube when you cut it does not necessarily assure you the same measurement for the finished job.

I am embarrassed on inspecting the binocular today as I write to find that I somehow managed to end up with 5mm of height extension instead of 2mm.

Test of new dimensions:

However not just the height of the eyecups, but also the position at which the binocular comes comfortably to the face, as determined by the width of eyecups, determines whether the binocular comes to the eyes at the point of eye relief.

An advantage of 'sleeve fitting' added layers to the eyecups is the easy adjustment, certainly of the height of eyecups, in the field.

So without checking whether I had achieved the target 2mm figure for the height extension, I went off to my local woodlands for a first trial.

In fact, as far as I could tell, with 5mm of extension of the height of the eyecups, coupled with an increase of width from 30mm to 39/40mm, I was consistently able to bring the binocular to my eyes at the point of eye relief. I experienced no blackouts. I got the full field of view.


Stephen


* 1mm is a low figure. I don't remember now why I chose it. I would normally choose at least 2mm

** Yarrelli in his posts lists internal widths. The difference between the external and internal width of the eyecups of the Swift is 1mm

*** My best fit to face figure seems as a matter of experience to lie in the 42mm to 46mm range. My present practice though is to start with a low increase of width or height, and only in the case of a well-used binocular to take the time and trouble to keep experimenting with higher figures. To go beyond a certain point, stretching inner tube to fit, or extending eyecups that one millimeter or two further, one can encounter practical limits
 

Attachments

  • IMG_3057 Swift Triton I Customisation.jpg
    IMG_3057 Swift Triton I Customisation.jpg
    288.9 KB · Views: 7
Last edited:

yarrellii

Well-known member
Supporter
More on eyecups. Small exit pupil and large eyecups.

These days I’m trying the Canon IS 8x20, that have a meager exit pupil of 2,5 mm, by most accounts this should make for a finicky eye position and a lower level of ease of view and viewing comfort, as it’s sometimes the case with 8x20 binoculars (mostly pocket binoculars). However, and this is just a personal perception (no intention to pontificate here, just telling a personal experience), the eyecups make all the difference.

The Canon IS 8x20 is an “odd” 8x20, in that it’s not intended as a pocket device, like many other sharing that objective diameter and magnification. Being an IS device, the electronic bits take some space, and the resulting size/shape and weight fit basically within the “compact” category (8x32). And then there’s the eyecups. The shape and size have been criticized, and honestly I don’t think Canon did a terrific job there. However, they do have one positive feature, they’re basically as wide as the eyecups on the 12x36 Canon IS III, and in “full size" binoculars territory.

The inner diameter of the Canon IS 8x20 is approx. 34 mm, while the Canon IS III 12x36 are approx. 35 mm. As you can see in the following image, despite the huge difference in objective size, 20 mm vs 36 mm (this is a whooping difference in area of 3,14 cm2 vs 10,18 cm2), the eyecups share a very similar diameter.

Canon820_08.jpeg

And here's the Canon IS 8x20 compared to the Swarovksi EL SV 8x32, that has some of my favourite eyecups in size and design. The inner diameter of the eyecups on the small Canon is actually larger than the EL, and in fact larger than some "full size" binoculars.

Canon820_09.jpeg

And what has been the outcome of these oversized eyecups (for such tiny objectives) in my case? A striking one: in spite of the small exit pupil, these binoculars work almost as any other “regular” binoculars. So, in my personal experience, it’s not about the exit pupil size, it’s about the eyecups! I’ve used some 8x20 or 8x25 with narrow eyecups (and double hinge, to make things worse), and the result was a very compromised level of comfort and lack of ease of view. On the other hand, I remember some binoculars with low magnification and big exit pupils, that theoretically should have given me a relaxed an easy view, but that was not the case. I can think of the Optolyth NG 7x42, that with a 6 mm exit pupil and low magnification proved to be finicky when it came to eye position and prone to blackouts: it had some pretty narrow eyecups. The 7x35 Leica Retrovid wasn’t that bad, but the eyecup size was the deal-breaker for me. I loved the view, but couldn't use them comfortably. I sold them.

So, in my case (again, not saying this is any universal truth, just a personal experience):
Big exit pupil + small eyecups: Compromised comfort. Won't work.
Small exit pupil + regular eyecups: Acceptable to "normal" level of comfort. Will work.
Small exit pupil + small eyecups: recipe for disaster.

I know that this is, to a certain extent, an oversimplification, and that there’s a lot more to ease of view and comfort than eyecup diameter, but this has been my experience so far and I find it interesting to share it, as well as learning from others' experiences. The two small exit pupil binoculars that I have that display large eyecups and single hinge (Nikon 7x20 CF III and Canon IS 8x20) offer a reasonable level of comfort and can be used for long periods of time without much compromise. The Canon have IS, which could be one reason they work well, but the Nikon don't, and they're also reasonably comfortable. On the other end of the scale, the other small exit pupil binoculars that I have (Leica Ultravid 8x20 and Swarovski Habicht 8x20; already on its way to a new owner’s home) that have small eyecups and double hinge have proven too big a compromise for me in terms of eye positioning and viewing comfort.
 
Last edited:

Pepitogrillo

Well-known member
Andorra
I find it very very curious that a Leica 8x20, certainly a more or less modern binocular, has eyepieces that compromise comfort of use so much!

Icono de Validado por la comunidad
 

yarrellii

Well-known member
Supporter
I find it very very curious that a Leica 8x20, certainly a more or less modern binocular, has eyepieces that compromise comfort of use so much!

View attachment 1446564
Well, I'm talking only about my personal experience. I've read experiences from other forum members and they seem to be happy with them. In my case, I can appreciate the incredible design of the Leica, its awesome optics and the sheer quality that it oozes. However, when in use, the whole experience is jeopardized by the narrow eyecups (and the double hinge doesn't help). But that's just me. I was shocked when I discovered how easy and relaxed the view though the Nikon 7x20 CF III was, and then again by how "un-8x20" the Canon 8x20 IS feel.
 
Last edited:

Stephen Prower

Well-known member
... I remember some binoculars with low magnification and big exit pupils, that theoretically should have given me a relaxed an easy view, but that was not the case. I can think of the Optolyth NG 7x42, that with a 6 mm exit pupil and low magnification proved to be finicky when it came to eye position and prone to blackouts: it had some pretty narrow eyecups. The 7x35 Leica Retrovid wasn’t that bad, but the eyecup size was the deal-breaker for me. I loved the view, but couldn't use them comfortably. I sold them ...
Yarrellii

Add Swift Osprey 7.5x42 to the Optolyth NG 7x42. I recently attempted to crack the problem that you mention.

The answer (as I reported on the Swift sub-Forum) turned out to be to customise the eyecups so that the binocular would come comfortably and consistently to the face with the eyes located precisely at the point of eye relief.

(1) I aligned the height of the eyecups precisely with the point of eye relief. (2) I bulked out the width of the eyecups to match the width of my eye sockets.

The binocular now provides me with the promised easy view.

Interestingly, what at first sight seemed to represent a fundamental optical issue with the design or specification of the Osprey seems in truth to have represented a simple, but certainly not trivial, ergonomic issue.


Stephen


I would prefer to avoid the much wider topic--You are braver than me!--of whether the persons who market binoculars have a fear of the customer's response to the cosmetics of wide eyecups.

Does 'Narrow', like 'Slim', equal 'Sophisticated? Does 'Wide', like 'Chunky', by contrast, equal merely 'Work-a-day' or 'Does the job'?
 
Last edited:

Upland

Well-known member
Eyecups that are short when extended are my pet peeve. I like putting the eyecups right up to my sockets and not have to fiddle with putting them onto my eyebrows. Not only does it take time when often images are fleeting. It also lets in stray light that is annoying and often leads to reflections in the barrels. I’ve tried the eye shields and while they eliminate stray light they’ve never felt comfortable to me. Love that Zeiss makes longer eyecups for the Conquests. Talked to a fellow in Zeiss customer service. He said lots of customers find the stock eyecups short so Zeiss addressed the problem. I wish other companies would do the same.
 

Hermann

Well-known member
Call me old-fashioned, but I still like the old fold-down rubber eyecups of the old Zeiss Dialyt series (8x30 BGAT*P, 10x40 BGAT*P, 7x42 BGAT*P and so on) a lot. Simple, straightforward, nothing much that can go wrong.

OK, you can lose them after you screwed them off for cleaning the lenses, but that's about it.

Hermann
 

Troubador

Moderator
Staff member
Supporter
Call me old-fashioned, but I still like the old fold-down rubber eyecups of the old Zeiss Dialyt series (8x30 BGAT*P, 10x40 BGAT*P, 7x42 BGAT*P and so on) a lot. Simple, straightforward, nothing much that can go wrong.

OK, you can lose them after you screwed them off for cleaning the lenses, but that's about it.

Hermann
I have some sympathy with this as I used a pair of Dialyts with the fold-down eyecups for 26 years, but my experience when reviewing a wide range of binoculars since then has made me wonder if I was just lucky with the Dialyts because I have certainly been grateful for eyecups with more than two positions to find the place where I could see the full fov and without blackouts.

Lee
 

Patudo

Well-known member
I wonder if there is an opening here for a quality third party manufacturer to produce eyecups for popular binoculars that better suit those who don't wear glasses - ie. longer, for models such as the Conquest HD, and maybe incorporating a rubber piece like the old Zeiss style eyecups Hermann mentions (which I also agree are the most comfortable and shut out side light best when using binoculars without glasses).

I'm not a massive fan of the current Zeiss SF eyecups and if I owned one and could replace them with a more solid product (similar to those used in the FL series or indeed the Conquest) I probably would.
 

Users who are viewing this thread

Top