"Swarovski 8.5x42 SV" or "Zeiss 8x42 HT" ? (1 Viewer)

james holdsworth said:

Zeiss measure eye relief from the top of the ocular ring, not the eyepiece glass surface, like Swaro.

I have a friend that wears glasses, has both the FL and SLC and says the eye relief is the same for both.

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Hi James,

I've heard that story before, and from some very well-respected people. However, I've come to believe that it's a urban legend reinforced by those who apparently don't have an eyeglass problem to contend with.

The standard SPIE definition of the XPD (exit pupil distance) or ER (eye relief) is the distance of the XP (exit pupil) from the last surface of the eyepiece. (* SPIE Field Guide to Binoculars and Scopes, by Yoder and Vukobratovich.) Is is likely that Zeiss, the preeminent optical company in the world, would arbitrarily change that standard? I doubt it, but if they did why would they? First, the correct ER would always be larger than the available ER, putting them at an advertising disadvantage to other companies who used the correct standard.

All texts use exactly the same definition, and my personal experience with all the models under discussion, and others, is consistent with the standard being adhered to across manufacturers. Otherwise, why have a standard? Granted, due to differences in eyecup design there are small differences in ease of use between binoculars having the same ER, but not all that much. The 18.5mm ER of the 8x42 SLC HD and 18mm ER of the Zeiss 7x42BGATP is a pleasure. The 16mm ER of anything else is simply a pain in the eye.

Ed

elkcub said:

Hi James,

I've heard that story before, and from some very well-respected people. However, I've come to believe that it's a urban legend reinforced by those who apparently don't have an eyeglass problem to contend with.

The standard SPIE definition of the XPD (exit pupil distance) or ER (eye relief) is the distance of the XP (exit pupil) from the last surface of the eyepiece. (* SPIE Field Guide to Binoculars and Scopes, by Yoder and Vukobratovich.) Is is likely that Zeiss, the preeminent optical company in the world, would arbitrarily change that standard? I doubt it, but if they did why would they? First, the correct ER would always be larger than the available ER, putting them at an advertising disadvantage to other companies who used the correct standard.

All texts use exactly the same definition, and my personal experience with all the models under discussion, and others, is consistent with the standard being adhered to across manufacturers. Otherwise, why have a standard? Granted, due to differences in eyecup design there are small differences in ease of use between binoculars having the same ER, but not all that much. The 18.5mm ER of the 8x42 SLC HD and 18mm ER of the Zeiss 7x42BGATP is a pleasure. The 16mm ER of anything else is simply a pain in the eye.

Ed

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I'm not sure what you are saying. Do you have problems with the ER on the FL series?

I'm just going fromwhat a glass-wearing friend, also an optics nut and very knowledgeable, has said - that [in practical terms] the ER is the same.

elkcub said:

Hi James,

I've heard that story before, and from some very well-respected people. However, I've come to believe that it's a urban legend reinforced by those who apparently don't have an eyeglass problem to contend with.

The standard SPIE definition of the XPD (exit pupil distance) or ER (eye relief) is the distance of the XP (exit pupil) from the last surface of the eyepiece. (* SPIE Field Guide to Binoculars and Scopes, by Yoder and Vukobratovich.) Is is likely that Zeiss, the preeminent optical company in the world, would arbitrarily change that standard? I doubt it, but if they did why would they? First, the correct ER would always be larger than the available ER, putting them at an advertising disadvantage to other companies who used the correct standard.

All texts use exactly the same definition, and my personal experience with all the models under discussion, and others, is consistent with the standard being adhered to across manufacturers. Otherwise, why have a standard? Granted, due to differences in eyecup design there are small differences in ease of use between binoculars having the same ER, but not all that much. The 18.5mm ER of the 8x42 SLC HD and 18mm ER of the Zeiss 7x42BGATP is a pleasure. The 16mm ER of anything else is simply a pain in the eye.

Ed

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Ed, I agree with you in that hardware measurements should all be the same and done by a standard protocol.

That said, I have measured eye relief that fell on eye cups though I can not remember specific examples at the moment. I seem to remember both Kimmo (can’t find a specific example though, so may be in error) and Henry finding the same on occasion.

I did find one specific example posted by Henry of a Zeiss example.

http://www.birdforum.net/showpost.php?p=1779003&postcount=3

PS: I think both the 8x42 and 8x56 Zeiss Victory are spec'd at 16mm.

james holdsworth said:

Zeiss measure eye relief from the top of the ocular ring, not the eyepiece glass surface, like Swaro.

I have a friend that wears glasses, has both the FL and SLC and says the eye relief is the same for both.

Click to expand...

elkcub said:

Hi James,

I've heard that story before, and from some very well-respected people. However, I've come to believe that it's a urban legend reinforced by those who apparently don't have an eyeglass problem to contend with.

The standard SPIE definition of the XPD (exit pupil distance) or ER (eye relief) is the distance of the XP (exit pupil) from the last surface of the eyepiece. (* SPIE Field Guide to Binoculars and Scopes, by Yoder and Vukobratovich.) Is is likely that Zeiss, the preeminent optical company in the world, would arbitrarily change that standard? I doubt it, but if they did why would they? First, the correct ER would always be larger than the available ER, putting them at an advertising disadvantage to other companies who used the correct standard.

All texts use exactly the same definition, and my personal experience with all the models under discussion, and others, is consistent with the standard being adhered to across manufacturers. Otherwise, why have a standard? Granted, due to differences in eyecup design there are small differences in ease of use between binoculars having the same ER, but not all that much. The 18.5mm ER of the 8x42 SLC HD and 18mm ER of the Zeiss 7x42BGATP is a pleasure. The 16mm ER of anything else is simply a pain in the eye.

Ed

Click to expand...

Yup! Deffo ...... Ed is spot on.

Zeiss themselves advertise it as such - there's a link buried on the Victory thread somewhere (no, I haven't got a photographic memory - let's just say that my interest stems from a vested interest!)

This 'urban legend' stuff seems to get trotted out regularly, but what folk forget is that there are a myriad design differences, in eyepiece /eyecup shape, width, mounting, flange heights, tolerances, even spherical abberation, and light cone characteristics, etc, etc, and these marry up with a whole bunch of individual anatomical and even physiological differences among users - shape (face, glasses - lens + frames), offsets, IPD spacing, lens type /thickness, even eye fatigue, viewing conditions etc, etc, etc. There's even some nifty little diagrams showing the eyecup / glasses interaction, floating around here as well .......

I would summize that all the different permutations and combinations could give an "effective" difference in the order of ~ a few mm in actual viewing of any particular bin + person "marriage". That is what is usually reported here. YMMV !! :cat:

The actual measured ER according to standard though, is a fixed quantum, and that is the figure that should be advertised.


Chosun :gh:

Hi James,

Hmmmm. Guess I was bringing both of your statements into question.

james holdsworth said:

Zeiss measure eye relief from the top of the ocular ring, not the eyepiece glass surface, like Swaro.

Click to expand...

I've seen this assertion several times, but for the reasons stated previously I seriously doubt that Zeiss would depart from the standard definition. Why wouldn't they state the technically correct ER?

james holdsworth said:

I have a friend that wears glasses, has both the FL and SLC and says the eye relief is the same for both.

Click to expand...

If you mean the 8x42 SLC HD (ER=18.5mm), I do not believe eye relief is "the same" as the 8x32 FL (ER=16mm). With my head/eyeglass dimensions, the SLC HD works beautifully and the FL simply does not. So I know they aren't the same. (Ok, I have a problem with the FLs.)

However, let me offer up a possible explanation. It may very well be that your friend has facial measurements that allow 16mm to work for him. It may also be (new thought? ) that once an individual's eye relief requirement is met, functionality is achieved and additional eye-relief isn't that notable; for practical purposes everything over the threshold is basically judged to be "the same." From my collection, for example, the 8x SLC HD, 7x42 BGATP, and Swift 828 (roof) each have sufficient eye relief for me. However, I really don't consider the greater eye relief in the 828 (19+mm) either notable or an added blessing.

So, my hypothesis is: Binoculars that are above the user's ER threshold: (a) appear "the same" as others that are above threshold, and (ii) don't benefit from additional eye relief.

Ed

PS. Chosun, didn't see your post. :t:

Ed,

I've noticed for myself that the length of the eye relief on binoculars has little to do with whether or not I can accommodate myself to it.

I think I recall (maybe my recollection is faulty though) you writing that you really liked your little Swarovski 8 x 20 which has short eye relief and I was wondering how you get along with those?

I know that I have no problems at all with the short eye relief on my Nikon EIIs but my SEs with longer eye relief require more precise eye placement when I use them. And yet my Swift 828, with even longer eye relief than the SE, is along with the EII one of the easiest binoculars to use that I have.

Bob

elkcub said:

So, my hypothesis is: Binoculars that are above the user's ER threshold: (a) appear "the same" as others that are above threshold, and (ii) don't benefit from additional eye relief.

Ed

PS. Chosun, didn't see your post. :t:

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Thats a good start to evaluate ER and ease-of-view.
But what about other factors who maybe corrupt the plain distance?

My Kowa Genesis 8x33 (ER 15mm) fits me way better than the
Zeiss Conquest HD 10x42 (ER 17mm) or
Swarovski EL 8x32 SV (ER 20mm).
The latter two having about the same level of ease-of-view.

So what additional factor has to be counted in?

P.S.
I dont wear glasses. I tried all bins with sunglasses (different ones) and lost about 50% of the FOV with all of them.

ceasar said:

Ed,

I've noticed for myself that the length of the eye relief on binoculars has little to do with whether or not I can accommodate myself to it.

I think I recall (maybe my recollection is faulty though) you writing that you really liked your little Swarovski 8 x 20 which has short eye relief and I was wondering how you get along with those?

I know that I have no problems at all with the short eye relief on my Nikon EIIs but my SEs with longer eye relief require more precise eye placement when I use them. And yet my Swift 828, with even longer eye relief than the SE, is along with the EII one of the easiest binoculars to use that I have.

Bob

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Hi Bob,

I'm not clear whether or not you use eyeglasses. Don't laugh, lots of people have strong opinions about eye relief who don't use them, but that is probably due to factors Chosun summarized above.

A few years ago my preference was for the 10x25 SLC, but that was before eyeglasses became a necessity. Recently I bought a Leica 8x20 BR, with 16mm eye relief (the best I could find for pocket bins), but it's annoyingly marginal. So basically I don't use them.

Do you use eyeglasses routinely?

Ed

oetzi said:

...
P.S.
I dont wear glasses. I tried all bins with sunglasses (different ones) and lost about 50% of the FOV with all of them.

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Hello, Oetzi.

I suspect your various sunglasses don't fit as close to your face as prescription eyeglasses would. Actually, I've got a few that also are unusable with binoculars.

With my prescription glasses on I can see 100% of the field (sharp field stop edge), using any of the binoculars I mentioned above having greater than 18mm eye relief.

Ed

When I measure eye relief, I use a little contraption that has a cylinder 40mm of diameter that is positioned against the eyecup, and has a sliding opaque flat surface inside. This measures the ER relative to the eyecup rim as long as the eyecup diameter does not exceed 40mm and the eyecup is conical. So, for almost all binoculars and but a few scopes, this gives the "effective" eye-relief distance, such as what Henry's method does.

Thus measured, results for some 8x42 models were as follows: Nikon EDG 17mm, Swarovski SLC HD 16mm, Zeiss Victory HT 15mm. These measurements have an estimated margin of error of +-0.5mm.

There is, however, an easier method for estimating available eye-relief, and that is simply by measuring the diameter of the eye lens (the outermost lens of the eyepiece, the one that you need to keep clean of eyelash grease). The diameter of the eye lens determines the maximum field of view/eye relief combination available, and since field of view specifications are generally reliable, of binoculars with identical or very close fields of view the one with the larger eye lens will have longer ER. The eye lens diameters for the above three binoculars were 24, 23 and 21mm respectively.

There are also very big differences in the "effective eye relief of eyeglasses," by which I mean how far in front of your cornea the front surface of your eyeglass lens rests. This depends both on facial anatomy and the design of the chosen eyeglass frames, and can easily be a bigger variable than that coming from different eyecup designs. However, I would estimate that differences in eyecup design will also result in 2-3mm variations in real/effective eye relief ratios, and this is the main reason why I don't use the standard protocol (or maybe just re-interpret it as meaning that the last surface of the eyepiece is any surface, not just the last lens surface).

The best way to know is always to test for yourself, but I have felt that measuring effective eye reliefs from the rim of the eyecup gives information that is a bit more useful and easier to compare between binoculars and scopes. The negative side is that it gives figures that are shorter than what are specified.

Kimmo

elkcub said:

I've seen this assertion several times, but for the reasons stated previously I seriously doubt that Zeiss would depart from the standard definition. Why wouldn't they state the technically correct ER?

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Because the theoretical value is useless, and does not tell you the usable eye relief?

Leif said:

Because the theoretical value is useless, and does not tell you the usable eye relief?

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Exactly

Lee

elkcub said:

Hello, Oetzi.

I suspect your various sunglasses don't fit as close to your face as prescription eyeglasses would. Actually, I've got a few that also are unusable with binoculars.

Ed

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Even with very small and close-fitting glasses, its not possible.
I think this is because of a too-close relation to very far ancestors and their deep-set eyes.

elkcub said:

Hi James,

I've heard that story before, and from some very well-respected people. However, I've come to believe that it's a urban legend reinforced by those who apparently don't have an eyeglass problem to contend with.

The standard SPIE definition of the XPD (exit pupil distance) or ER (eye relief) is the distance of the XP (exit pupil) from the last surface of the eyepiece. (* SPIE Field Guide to Binoculars and Scopes, by Yoder and Vukobratovich.) Is is likely that Zeiss, the preeminent optical company in the world, would arbitrarily change that standard? I doubt it, but if they did why would they? First, the correct ER would always be larger than the available ER, putting them at an advertising disadvantage to other companies who used the correct standard.

All texts use exactly the same definition, and my personal experience with all the models under discussion, and others, is consistent with the standard being adhered to across manufacturers. Otherwise, why have a standard? Granted, due to differences in eyecup design there are small differences in ease of use between binoculars having the same ER, but not all that much. The 18.5mm ER of the 8x42 SLC HD and 18mm ER of the Zeiss 7x42BGATP is a pleasure. The 16mm ER of anything else is simply a pain in the eye.

Ed

Click to expand...

Yo Ed and Chosun

Here is what Henry found (see link above):

'I found the 8x42 FL to have about 16mm from the eyecup, and almost 18mm from the eyelens'.

16mm is what Zeiss quotes and I am prepared to believe Henry can measure quite accurately.

Looks to me as if this urban legend is true.

Lee

Troubador said:

Yo Ed and Chosun

Here is what Henry found (see link above):

'I found the 8x42 FL to have about 16mm from the eyecup, and almost 18mm from the eyelens'.

16mm is what Zeiss quotes and I am prepared to believe Henry can measure quite accurately.

Looks to me as if this urban legend is true.

Lee

Click to expand...

Mythbusted! :brains:

Lee, I know you'd like to believe it - but it just ain't so.
Not disputing what Henry measured - I'd put that down to a combo of measurement error%, and perhaps some specification rounding or some such by Zeiss (maybe even one of their famous - up to, and more than xx mm ER-type lines!!) :-O
This is a direct quote from the horse's mouth ....... "distance from the exit pupil to the last lens vertex of the eyepiece" :smoke:
http://sportsoptics.zeiss.com/hunting/en_de/service-support/usage/optics-abc.html

Hoping to put this one to bed, once and for all ...... :gn:

(trust that the smilie count meets with your approval?!!) 8-P


Chosun :gh:

Chosun Juan said:

Mythbusted! :brains:

Lee, I know you'd like to believe it - but it just ain't so.
Not disputing what Henry measured - I'd put that down to a combo of measurement error%, and perhaps some specification rounding or some such by Zeiss (maybe even one of their famous - up to, and more than xx mm ER-type lines!!) :-O
This is a direct quote from the horse's mouth ....... "distance from the exit pupil to the last lens vertex of the eyepiece" :smoke:
http://sportsoptics.zeiss.com/hunting/en_de/service-support/usage/optics-abc.html

Hoping to put this one to bed, once and for all ...... :gn:

(trust that the smilie count meets with your approval?!!) 8-P


Chosun :gh:

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Well that's told me alright LOL :eat:

I really did think this was true as I haven't had any probs over the last 9 years with a heap of different spectacles and sunglasses with my FLs and more recently with the HTs. With other folks getting jumpy at the idea of 16 mm cramping their style and with Henry's measurement I really did think that Zeiss must measure in a different way.

Next time you are in the UK I shall prostrate myself in front of you (I don't think its legal in Aussie, or at least too many people would laugh) and the beers are on me B

And yes your emoticon works for me

Troub

Zeiss ... High-eyepoint eyepieces (B), wide-angle high-eyepoint eyepieces (Ww) A high-eyepoint eyepiece provides a full field of view with and without eyeglasses. Due to a special design of the optics developed by Carl Zeiss, the exit pupil is located at least 15 mm away from the last lens vertex. This allows you to bring the pupil of your eye into the exit pupil even if you wear glasses. ...

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It's pretty clear they measure from the vertex of the eyelens, and their published specs refer to such distances.

It's also pretty clear to me they don't understand the needs of the eyeglass community very well.

Many thanks, Chosun.

Ed

elkcub said:

It's pretty clear they measure from the vertex of the eyelens, and their published specs refer to such distances.

It's also pretty clear to me they don't understand the needs of the eyeglass community very well.

Many thanks, Chosun.

Ed

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Well they understand my needs OK Ed. Perhaps they're just picking on you.

Perhaps their Zeiss/Sola/AO business division making spectacles lenses ought to speak to Zeiss Sport Optics more often.

Or maybe its not that many people that find 16 mm inadequate. But for sure there is a bigger variety of spectacle frames and lenses these days than there ever was.

Lee

elkcub said:

If I understand this statement correctly, 16mm is certainly not "more than enough" eye relief for those who must wear glasses. The extra 2.5mm afforded by the Swaro 8x42 HD makes a world of difference, and for me it's a critical factor when comparing products.

Just my opinion, of course.
Ed

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In optics design an ER of 15mm is sufficient for spectacle wearers.obviously there are exceptions for individuals, but in optics design it is certainly enough.
mak

mak said:

In optics design an ER of 15mm is sufficient for spectacle wearers.obviously there are exceptions for individuals, but in optics design it is certainly enough.
mak

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Well, it might be worthwhile to review what George Smith and David Atchison had to say on the subject in their masterwork "THE EYE and Visual Optical Instruments," 1997. Incidentally, they also define eye relief as "the distance between the back vertex of the eye lens or eyepiece and the exit pupil," — just so we are on the same sheet of music. As if the issue weren't complicated enough, the optics of the eyeglasses themselves enters the picture. (I think Chosun may have suggested this in an earlier post.) That being the case, here we have yet another source of individual differences in addition to the anatomical and mechanical.

The second reference from Pantazis Mouroulis' excellent Visual Instrumentation, Optical Design and Engineering Principles," 1999, provides some hint of the potential extent of the problem. Beyond age 50 more than 50% of the population uses eyeglasses!

Anyway, I'll leave it to you to show where "... In optics design an ER of 15mm is sufficient for spectacle wearers." In the meantime, it's not unreasonable to say that Zeiss (and Leica) haven't done much to address the issue for many people who wear glasses. But, hey, who am I to argue with those who are satisfied? I'll just buy from Swarovski ... along with many in my age cohort.

Ed

PS. Personally, I think the notion that 16mm ER (much less 15mm) is sufficient for eyeglass wearers resulted from corporate wishful thinking supported by testimonials from a small percentage of the population who were satisfied.

PPS. The Smith & Atchison estimate of 20-22mm can be reduced by a few mm because the instrument is typically pressed against the eyeglasses for stability. The same can be said about Mouroulis' statement. We then find that 18-20mm would be ideal for binoculars, a criterion that Swarovski happily meets with its latest offerings.