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Why is it such a common problem now days for binoculars to have too much eye relief r (2 Viewers)

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Why do binoculars have too much eye relief for eye cup length lately?

I have purchased 6 binoculars over the last year and I have had to return 4 of them for having too much eye relief relative to how far the eye cups extend. This forces you to figure out how to brace the binoculars because you can't rest them in your eye sockets.The two that worked good for eye relief were the new Swarovski 8x30 CL and the Nikon 8x30 EII and Canon 10x42 IS-L. The CL is the best and has very tolerant eye relief. The four I returned were the Cabela's Euro Instinct HD 8x32 , Bushnell M HD 8x42, Nikon Monarch MHG 8x42 and recently the new Zeiss Victory 8x25. The little Zeiss I had to hold an inch away from my face to avoid blackouts. Is this a recent phenomenon and have you guys been having this problem also and why? Is it because I have shallower than normal eye sockets? What binoculars have you tried work well for you and which ones have you tried that don't work well or have too much eye relief relative to the eye cups.
 
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It is because binoculars are now designed to allow nearly all to see the full field of view.
If some eye glass wearers complain of too little eye relief, the designers seem to think that every binocular must be made to suit them. If these long eye relief users shout loudly enough they must be heard.

What results is that most binoculars have what I feel are pathetic FOVs for modern eyepiece design possibilities.
I find it amusing or not so amusing to read the great number of adverts and binocular companies blurb boasting of enormous FOVs that are actually pathetic.
If one reads enough of these false claims, they must be true, mustn't they?

Astro eyepieces with 82 degree, 90 degree, and 100 degree fields are common. 120 degrees are available.
But binoculars are still in 'The Stone Age'.

As to why eyecups are too short.
Dunno!
 
Given the size of some of some of those ultrawide eyepieces you’d likely have to chop your nose off to see through two of them at the same time. Maybe the physical length of these eyepieces (due to the number of glass elements makes it hard to integrate them with the necessarily short focal length of typical binocular objectives. On a related note, what kinds of apparent field of view are considered “really wide” with birding scopes... I use a 13mm Nagler in mine.

PeterW
 
[email protected] said:
I have purchased 6 binoculars over the last year and I have had to return 4 of them for having too much eye relief relative to how far the eye cups extend. This forces you to figure out how to brace the binoculars because you can't rest them in your eye sockets.The two that worked good for eye relief were the new Swarovski 8x30 CL and the Nikon 8x30 EII. The CL is the best and has very tolerant eye relief. The four I returned were the Cabela's Euro Instinct HD 8x32 , Bushnell M HD 8x42, Nikon Monarch MHG 8x42 and recently the new Zeiss Victory 8x25. The little Zeiss I had to hold an inch away from my face to avoid blackouts. Is this a recent phenomenon and have you guys been having this problem also and why? Is it because I have shallower than normal eye sockets? What binoculars have you tried work well for you and which ones have you tried that don't work well or have too much eye relief relative to the eye cups.
Click to expand...

Agreed.

It is great to have additional eye relief to accommodate eye glass wearers but then that brings up the question as to why the eye cups do not extend a little more.

I have wondered if it could be that the eye piece housings are to short for a longer eye cup to retract close enough to the eye piece lens surface for eye glass wearers. Could that be true?

Models that work best for me are most Swaro products, the Zeiss Conquest HD 10X42 with the optional longer eye cup, the Canon 10X42 IS and the Nikon 8X42 Aculon. The Canon and the Aculon are the only two where I can actually turn in the eye cup a notch as delivered. The Canon is not very comfortable due to the large diameter.

Some models where I have to take a higher hold are the Noctivid, Zen-Ray ED3, GPO ED 8X32, Nikon Monarch 7 8X30 and Opticron Traeller 8X32.

Most of the others work but there is not much slack.
 
It may be that the designers calculate the eye cup extension based on the optical ER and not the actual ER, which in my experience is often much less (5-7mm less in a couple of pairs I recently bought). OR, it could be that many manufacturers are using off-the-shelf eye cups when they should be specific to the actual binocular design.
 
paul2013 said:
It may be that the designers calculate the eye cup extension based on the optical ER and not the actual ER, which in my experience is often much less (5-7mm less in a couple of pairs I recently bought). OR, it could be that many manufacturers are using off-the-shelf eye cups when they should be specific to the actual binocular design.
Click to expand...
I think you are on the right track here. Maybe eye cup design is not keeping up with optics.
 
I have several twist up eyecup models, allows you to adjust where you put your eyes, glasses or not. Seem to work fine, better than the no/hard fixed rubber eyecup designs of yesteryear:

PeterW
 
wllmspd said:
Given the size of some of some of those ultrawide eyepieces you’d likely have to chop your nose off to see through two of them at the same time. Maybe the physical length of these eyepieces (due to the number of glass elements makes it hard to integrate them with the necessarily short focal length of typical binocular objectives. On a related note, what kinds of apparent field of view are considered “really wide” with birding scopes... I use a 13mm Nagler in mine.

PeterW
Click to expand...

If you are not Asian, but are a big-nosed Caucasian, try a pair of Fujinon FMT-SX in16X70, and I guarantee you will appreciate what this post is about.
 
Lack of enough eye relief has been a sore spot with me all along. Swaro's and in particular the old Vortex Fury have worked best for me. The frames of your eye glasses can make a huge difference. I tend to prefer big frames and that rules out most binoculars.
 
Those who affect contact lenses would seem to have the same eye relief requirements as the "naked eyeball" crowd, wouldn't they?
 
As soon as I read the title, I was expecting all 8 power. I was right. 8's seem to have this issue much more than 10's. I had a pair of 8.5x43 Brunton Epoch that had exceptional glass, but finally returned them due to this same problem. I was told the 10.5's did not.
 
As one of those myopic individuals who need longer eye relief (c.15mm from the eyepiece cup surface in the fully lowered position) the depth by which the ocular is recessed can make long (?) eye relief bins, such as Swaro EL SVs, too short. Design by lawyers?

I have Zeiss bins with quoted ERs lower than the Swaros that work fine for me. I suggest Zeiss et al might sell more if they clarified the measurement method they adopt.

As to FOV, I lack the design knowledge to comment other than to repeat the old saw that if there is a will there is a way.

I'm just glad that I can see the FOV without a tunnel effect in bins with adequate, for me, eye relief.
 
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Hi,

the reason is certainly the call for more ER by the glasses crowd. Unfortunately the exit pupil has a finite length, depending on the optical design (which is kinda limited since the customer doesn't want long focal length binoculars).

Twist-Up eyecups can also be only twice as long extended as compared to unextended which is a problem if some customers demand 20mm ER and more but others need less than half of that.

Zeiss did the right thing with the conquest models and different eyecups to use depending on ER needs. I would hope to see this more frequently but of course this will make the beancounters unhappy because it adds 50 cents to the production costs of a $3k premium product.

Joachim
 
[email protected] said:
I think you are on the right track here. Maybe eye cup design is not keeping up with optics.
Click to expand...
Surely this is the answer, unless people also want to complain about the narrowing of the FOV that comes with longer relief.

If it's impossible to design an eyecup that can move out that far, why not provide interchangeable eyecups, with a long set that doesn't screw back in as far, and a short set that don't screw out as far.

As a glasses wearer, I'm all for longer relief, but (I think) I'd be ok with shorter relief, so long as there's some kind of marking in the field of view to help me centre it. I don't need to see the edge, I just need to know where it is.
 
Posts 14,19.

The reason is simple.

The focal length of the eyepiece is longer in 8.5x than 10.5x with the same objectives.
So, for similar design eyepieces the eye relief is longer.

Say, 160mm focal length objectives.
8.5x gives 19mm fl eyepieces.
10.5x gives 15mm fl eyepieces.

There are design tricks to alter eye relief, but this may result in narrower fields or other consequences.

P.S.
That is also why 10.5x or 10x binoculars often have wider AFOVs than 8.5x or 8x binoculars.
The eyepieces have shorter focal lengths and bigger AFOVs with higher magnifications.
 
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