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8/8.5x42 SF vs Swaro EL eye relief (1 Viewer)

C

CMB

Well-known member
United States
Have a family memeber who wears glasses, has an astigmatism, and needs 20mm of eye relief for proper viewing through bins and scopes.

Their current pair of bins is a 10x32 Swaro EL Field Pro edition, which works very well for them and they love.

Looking to move to an 8/8.5x42 to get a larger exit pupil to reduce eye fatique during full days of viewing.

The balance shift of the new SFs is also very appealing in a full size binocular.

Can anyone with experience with both the SF and the Swaro EL Field Pro edition (with 20mm eye relief) speak to whether the SF's eye relief is really shorter than the Swaro EL? We know what the specs say in terms of eye relief.

In other words, is the eye relief actually the same but measured differently between the brands, or is there actually a 2mm difference in eye relief?

We have the option of ordering both to test, and send one back, but that does involve extra cost. If folks that have used them already know if the eye relief is different between the two that would help.

Thank you for your time and help.

Chris
 
Hello Chris,

I have both binoculars, am far-sighted glasses wearer and the Swarovski has the clearly better insight, but the SF is still going well, for people with eye-glasses both can be used, but as I said, Swaro is in front.

Andreas
 
Hi Andreas,

Thank you very much for your reply. That is a help.

Sometimes there is a need to throw on a set of Cacoons over-the-frame sunglasses while observing. Those add some more distance/thickness to the eye relief needed.

We had a feeling what direction we needed to go, but your comments help.

Chris
 
CMB said:
Have a family memeber who wears glasses, has an astigmatism, and needs 20mm of eye relief for proper viewing through bins and scopes.

Their current pair of bins is a 10x32 Swaro EL Field Pro edition, which works very well for them and they love.

Looking to move to an 8/8.5x42 to get a larger exit pupil to reduce eye fatique during full days of viewing.

The balance shift of the new SFs is also very appealing in a full size binocular.

Can anyone with experience with both the SF and the Swaro EL Field Pro edition (with 20mm eye relief) speak to whether the SF's eye relief is really shorter than the Swaro EL? We know what the specs say in terms of eye relief.

In other words, is the eye relief actually the same but measured differently between the brands, or is there actually a 2mm difference in eye relief?

We have the option of ordering both to test, and send one back, but that does involve extra cost. If folks that have used them already know if the eye relief is different between the two that would help.

Thank you for your time and help.

Chris
Click to expand...
The 8X42 SF has more usable eye relief than the Swarovski 8.5X42. I own the 8.5X42 SV and use it with eye cups closed. With the SF 8X42 I MUST extend the eye cups to the first stop...because it has so much usable eye relief. The SV works fine for me but the SF is very tempting solely due to its generous eye relief.

PS
I wear eyeglasses. My old SLC 7X42 has so much eye relief I often extend the eye cups. The SF behaved the same way for me.
 
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Pileatus said:
The 8X42 SF has more usable eye relief than the Swarovski 8.5X42. I own the 8.5X42 SV and use it with eye cups closed. With the SF 8X42 I MUST extend the eye cups to the first stop...because it has so much usable eye relief. The SV works fine for me but the SF is very tempting solely due to its generous eye relief.

PS
I wear eyeglasses. My old SLC 7X42 has so much eye relief I often extend the eye cups. The SF behaved the same way for me.
Click to expand...

Agree. When I had both I actually put an o-ring on the SF 8X42. The SV could ALMOST use one for me, but not quite.
 
Pileatus and Chuck,

Thank you both for your responses. Your experience seems to be opposite of Andreas', which raises a question.

Pileatus and Chuck, are you near sighted or farsighted, and do either of you have an astigmatism? Andreas mentioned that he is farsighted.

I found an old thread where some folks said that nearsighted eyeglass wearers require less eyerelief than farsighted eyeglass wearers. I have never heard this before.

Thank you for your comments.

Chris
 
Last edited:
CMB said:
I found an old thread where some folks said that nearsighted eyeglass wearers require less eyerelief than farsighted eyeglass wearers. I have never heard this before.
Click to expand...

Hi Chris,

that is usually correct, but it also depends on the shape of the face and the frame of the glasses!

I tested both binoculars for you again, with eyeglasses!
When I put the eye cups one step high, I can't see the field of view of both binoculars, I put the eye cups all the way down, the viewing behavior in Swarovski is visibly more comfortable for me and therefore better.
Myopic glasses wearers often come with a 15mm. AP location right, I need at least 16mm. to be able to use binoculars.

Andreas

P.S. > Pileatus and Chuck <

What do you see in the Zeiss SF when the eyecups are at the bottom?
 
Last edited:
Conndomat said:
Hi Chris,

that is usually correct, but it also depends on the shape of the face and the frame of the glasses!

I tested both binoculars for you again, with eyeglasses!
When I put the eye cups one step high, I can't see the field of view of both binoculars, I put the eye cups all the way down, the viewing behavior in Swarovski is visibly more comfortable for me and therefore better.
Myopic glasses wearers often come with a 15mm. AP location right, I need at least 16mm. to be able to use binoculars.

Andreas

P.S. > Pileatus and Chuck <

What do you see in the Zeiss SF when the eyecups are at the bottom?
Click to expand...

Based solely on memory, with the Zeiss SF I need one click on the eye cups. The black version (latest) has the perfect 1st click setting for my viewing pleasure. With eye cups closed I'm in that zone where things can get uncomfortable. With my 8.5XSV, closed eye cups is the best position.
 
I'm mildly myopic (-2 roughly) and have fairly standard plastic rimmed glasses with high index polycarbonate lenses. I can see very comfortably with no kidney beaning or discomfort or any issues with the 8,5x42 and 10x42 Swaros and with the 8x42 SF. On all three I leave the eye cups completely collapsed. I've not used the 10x42 SF.

Both are fantastic bins, in my eye the two best 8x42s on the market, though I prefer the ergonomics, FOV, and focuser of the Zeiss.
 
CMB said:
Pileatus and Chuck,

Thank you both for your responses. Your experience seems to be opposite of Andreas', which raises a question.

Pileatus and Chuck, are you near sighted or farsighted, and do either of you have an astigmatism? Andreas mentioned that he is farsighted.

I found an old thread where some folks said that nearsighted eyeglass wearers require less eyerelief than farsighted eyeglass wearers. I have never heard this before.

Thank you for your comments.

Chris
Click to expand...

Hi Chris,

You may be referring to my old post from 2013 HERE. Although at the time everyone seemed satisfied that myopes and hyperopes have different eye relief requirements, that optical factor never really entered into further discussion. Indeed, yours is probably the first mention of it.

Depending on its severity, hyperopia generally leads to a greater eye relief demand than myopia. But there are other consequences as well; hyperopes experience a larger image size, longer short-focus, and a narrower field of view than myopes. The underlying reason is that hyperopes use positive and myopes use negative corrective lenses, which change the 'effective' positions of their eyes' entry pupils.

I'm moderately farsighted at 3.5D and only comfortable with an ER ≥ 18mm, regardless of manufacturer.

Ed
 

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elkcub said:
But there are other consequences as well; hyperopes experience a larger image size and a narrower field of view than myopes.
Click to expand...

Hi Ed,

nice Report!:t:

How is this to be understood, is the magnification with binoculars larger if a far-sighted see through ???
Example, an 8x becomes 8,3x?

Andreas
 
Pileatus said:
It means I'm more comfortable with the eye cups extended one stop...the one added for people who need just a bit more space between their eye and the lens.
Click to expand...

... but that would mean that the Swarovski has the longer AP location because they already feel comfortable down here?!

Andreas
 
Every so often the subject of eye relief arises along with technical discussions which often do more to confuse than assist. Blame the Internet because one simple look through a binocular can easily convey all there is to know about one's preferences. You like it or you don't.

I wear clear eyeglasses and prescription sunglasses. The clear lenses are very thin (I pay for that) so I don't fight for a good view with my bins. The polarized sunglasses are thicker so I lose some FOV but the eye comfort on a bright day is amazing. Compromises galore!

The specs giving by manufacturers are often misleading. A 20mm here functions just like an 18mm there and that 17.4mm is too much for a lot of people.

Swarovski 8X32 Swarovision = 20mm
Swarovski 8.5X42 Swarovision = 20mm
Swarovski 10X50 Swarovision = 20mm
Swarovski 7X42 SLC = 19mm

Guess which one has the most usable eye relief? Yep, the 7X42 SLC. I love it with sunglasses!
Next best "walk-in" view is the 8X32 Swarovision.
The 8.5X42 and 10X50 are about the same...the 10X50 seems a smidgen easier.

Also, the 17.4 mm eye relief on the Nikon 8X32 SE is plenty for me and more than many can handle due to blackouts.

My Ultravid 7X42 BR supposedly has 17mm and it's not quite enough for me.

IMHO, based on personal observations, the Zeiss SF black version with 18mm eye relief functions exactly like my 7X42 SLC (19mm eye relief). I need to extend the eye cups for comfortable viewing. In contrast, I never extend the eye cups on my 8.5X42 Swarovision (20mm eye relief).

If only they would measure eye relief from the edge of the eyecup!!
 
Last edited:
Conndomat said:
Hi Ed,

nice Report!:t:

How is this to be understood, is the magnification with binoculars larger if a far-sighted see through ???
Example, an 8x becomes 8,3x?

Andreas
Click to expand...

Andreas,
In short, yes. From the Internet:
Corrective lens are either positive or negative in power. Negative or minus lenses cause light to diverge. Positive or plus lenses cause light to converge. ... They either magnify or minify the image viewed when a person holds a lens away from their face to view an object.
Click to expand...
So, your eyeglass prescription has a fairly large impact on your eye relief requirement, the most important distinction being far- vs. short-sightedness.

To actually demonstrate that presbyopes experience larger images, farther short-focus and narrower fields-of-view, however, would require a psychophysics laboratory that is beyond the interest/capability of optics manufacturers or the general public. Hence, the topic has taken no traction. But it does explain why your experience would be different from an eyeglass-wearing myope using identical binoculars.

Ed
 
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Pileatus said:
Every so often the subject of eye relief arises along with technical discussions which often do more to confuse than assist. Blame the Internet because one simple look through a binocular can easily convey all there is to know about one's preferences. You like it or you don't.

I wear clear eyeglasses and prescription sunglasses. The clear lenses are very thin (I pay for that) so I don't fight for a good view with my bins. The polarized sunglasses are thicker so I lose some FOV but the eye comfort on a bright day is amazing. Compromises galore!

The specs giving by manufacturers are often misleading. A 20mm here functions just like an 18mm there and that 17.4mm is too much for a lot of people.

Swarovski 8X32 Swarovision = 20mm
Swarovski 8.5X42 Swarovision = 20mm
Swarovski 10X50 Swarovision = 20mm
Swarovski 7X42 SLC = 19mm

Guess which one has the most usable eye relief? Yep, the 7X42 SLC. I love it with sunglasses!
Next best "walk-in" view is the 8X32 Swarovision.
The 8.5X42 and 10X50 are about the same...the 10X50 seems a smidgen easier.

Also, the 17.4 mm eye relief on the Nikon 8X32 SE is plenty for me and more than many can handle due to blackouts.

My Ultravid 7X42 BR supposedly has 17mm and it's not quite enough for me.

IMHO, based on personal observations, the Zeiss SF black version with 18mm eye relief functions exactly like my 7X42 SLC (19mm eye relief). I need to extend the eye cups for comfortable viewing. In contrast, I never extend the eye cups on my 8.5X42 Swarovision (20mm eye relief).

If only they would measure eye relief from the edge of the eyecup!!
Click to expand...

Pileatus, Thanks for sharing these observations. Very helpful for me.

I agree the 8x32 Swarovision is effortless with glasses.
On the other hand, I'm surprised that the Ultravid 7x42 BR is not enough for you, as I can see the whole view with my specs on, and at the same time do not need to extend eyecups on the 8x42 SF, so there's more variables to 'the fit' than I realized. Admittedly, the eyecups on the Ultravid BR are visually pretty deep.

The interesting news is that you can see the whole field with the Nikon 8x32 SE.
I've stayed away from those because I assumed they wouldn't fit me.

Research is needed...

I agree that 'usable eye relief' specs would be very helpful to the consumer, as it might actually create a usable standard, as opposed to one fraught with an unknown variable. Ideally they would publish both... along with light transmission specs that are truthful...

Thanks for your post. It can be so disappointing when binoculars don't fit.

-Bill
 
I have greatly appreciated all of the comments. It has been very instructive, and has helped us to have a better understanding of what we are experiencing.

I think I have gotten the basics of what has been shared.

We are dealing with a -7DP prescription in our household. Even when paying for premium grade "thin" lenses, they are still thick and may automatically put the occulars a bit farther away than other folks who are less nearsighted/myopic. The type of frame used also affects how far out from the pupil the front plane of the glasses sit. A frame with built-in/molded nosepieces can't be adjusted like a frame with wire mounted nosepieces. So while myopia may require less eye relief in general, the particular lens thickness and frame in use may negate that to some degree.

The family member has usually favored 10x binoculars over 8x. Understanding that a -7DP would decrease the image size may help to explain why the individual leans towards 10x.

So when looking at the Zeiss SF vs the Swaro EL... A 10x42 SF provides just about the same field of view as the 8.5x42 Swaro, but the 10x42 might help offset the reduction in magnification caused by the -7DP prescription. At the same time the extra 0.5x in the 8.5x of the Swaro helps too.

So if we were to order an SF to do a comparison we understand why it might be better to compare a 10x42 SF rather than an 8x42 SF.

The downside of the SF would be the slightly smaller exit pupil, the rolling ball/distortion effect, and the image not being as crisp/sharp edge to edge.

The Swaro 8.5x42 EL FP version works great for the individual with the cups collapsed all the way. They have full FOV when using them, and the larger exit pupil helps make a long day in the field more relaxed.

The difference might be than when using over the frame Cocoons sunglasses, the SF might give a bit more useable eye relief.

That is what I've been able to reason through from the discussion.

Thank you again for all of your comments. It has been a help.

Chris
 
There are two other major factors that a 'useable eye relief' specification from the bino brands would not help with.

For spectacle wearers there is not only the thickness of the lenses and the frame but also where they position the spectacles on their nose. This is influenced by the side bars that go behind the ears but also by where the wearer feels they are most comfortable. Changes in this position change the distance of the bino eyepiece from the eyes.

For non-spectacle wearers there is the outer diameter of the eyecup and how this fits into their eye socket. This factor wasn't apparent to me until I grabbed two binos and used them without my spectacles. One was a Victory Pocket with small diameter eyecups that sank too deeply into my eye sockets and needed bracing a little way away from my eyes. The other was the Kowa 6.5x32 which has eyecups with a much larger diameter than the Victory Pocket and it was immediately obvious they fitted into my eye sockets quite differently. I should mention that it seems possible with some folks that the width of the nose might play a part too.

Given these factors it might be that bino manufacturers do not see much point in changing from an optical definition of eye relief to one based on how much is 'available' above the rim of the eyecup.

Lee
 
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