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swarovision EL (1 Viewer)

It may be that there is a causal relationship between field curvature (i.e., a "flat field") and "rolling ball" perception, but to my knowledge this psychological phenomenon is primarily associated with the aberration of distortion.

Field curvature has to do with the the focal surface of the image, which is, essentially, a spherical cap. Depending on the expert, some amount of field curvature is considered beneficial for the observer. Still, some people want to eliminate it altogether. Distortion has to do with image magnification as a function of field angle, — where increasing magnification results in pincushion distortion and decreasing magnification results in barrel distortion. (Only the unique case of constant magnification results in a rectilinear image.) Some amount of pincushion is beneficial to the observer for minimizing rolling ball perception; still, some people want to eliminate it altogether.

Because the two parameters are design independent, a completely flat field binocular may be given sufficient pincushion distortion to minimize rolling ball perception. Vertical images viewed at the edge will curve outwards to some extent, but still be in focus. Conversely, an instrument that produces a perfectly rectilinear image across the field will necessarily produce some rolling ball perception. It may or may not be given field curvature, depending upon the design, so that the edges may be somewhat out of focus.

What it comes down to, therefore, is that the user must ultimately decide what amount of these two aberrations is most effective for his/her own viewing needs. All the rest is either strong opinion or commercial rhetoric. ;)

Ed
 
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ClayTaylorTX said:
All -

The best explanation for the "rolling ball" that I can give is to imagine you are standing on a railroad track, with the rails extending out to your right and left. The cross-ties at your feet look to be evenly spaced, but as you look down the rails, the ties appear to be closer together. Sounds obvious, right?

In a binocular with no field-flattener, objects that are evenly spaced across the field of view, even if they are in fact getting closer together at the periphery of your vision, appear to be consistently spaced. In other words, the curved-field in fact distorts. This is what our eyes and brain are "used to seeing".

In the field-flattener binocular, the spacing actually appears to diminish at the edges of the field, creating the effect of a visual "compression", or the "rolling ball".

Personally, I notice something of that compression as I pan side-to-side, but it never is enough to distract me from the image at hand.

Clay Taylor
Swarovski Optik N.A.
Click to expand...

Here are geometric illustrations of what Clay described above:
http://www.arielnet.com/Main/images/fig1f.gif

Technically, this is actually an illustration of barrel distortion in a lens, which is a true distortion like pincushion, but lack of pincushion produces a very similar perceptual effect in optics.

Holger Merlitz uses moving images in his technical report to illustrate the the "globe effect" (his name for "rolling ball") that illustrate closer to what you actually see (if you see it!).

http://www.holgermerlitz.de/globe/distortion.html

The upside to "rolling ball" is that the images in the center field look even larger than normal. Given that roof prisms give a larger image scale than comparable magnification porros to begin with due to their close set barrels, the image scale through the 10x42 LX/LX L was huge in the center.

Unfortunately, the image scale became smaller at the edges (or to use the technical jargon - "squished").

It's this imbalance between the inside and outside image scale that gives the impression of the image scrolling over a ball, and when you move the bin, you get a "rolling ball".

Even the night sky looked like curved like Ptolemy's Crystalline Spheres through the LX L.

Some manufacturers can give you too much of a good thing by adding too much pincushion.

Then the views look like this:
http://upload.wikimedia.org/wikipedia/en/9/97/Pincushion-distortion.jpg

When I looked at my computer screen with the ZR 7x36 ED2, it had a saddle shape appearance.

Fortunately, while panning at longer distances, the pincushion wasn't distracting like "rolling ball," but I have used bins with too much pincushion that produced an inverse "rolling ball" while panning, for example, the 10x42 Swift Ultralite and the Swift 8x44 ED Ultralite.

The good news is that some people who initially see "rolling ball" eventually adapt to it.

So if you are not sure how you react to "rolling ball," order your SV EL from a store with a liberal return period so you have time to see if you can adapt to it.
 
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ingle1970 said:
I take it you like them John ! :-O
good report by the way .

did you notice the "rolling ball effect" as Manfred mentioned earlier ? .
Click to expand...

Yes, I like them very much and I've already found a buyer for my original pair.

No, I didn't notice the rolling ball effect when I used them yesterday and then I tried them again today for the purpose of looking specifically for it but I still did not notice anything unusual or feel any kind of eyestrain or discomfort while using the new ELs.
 
John Finnan said:
Yes, I like them very much and I've already found a buyer for my original pair.

No, I didn't notice the rolling ball effect when I used them yesterday and then I tried them again today for the purpose of looking specifically for it but I still did not notice anything unusual or feel any kind of eyestrain or discomfort while using the new ELs.
Click to expand...

May the Irish hills caress y'an.
May her lakes and rivers bless y'an.
May the luck of the Irish enfold y'an.
May ya be blessed with the eyes of Finnan.
 
John Finnan said:
No, I didn't notice the rolling ball effect when I used them yesterday and then I tried them again today for the purpose of looking specifically for it but I still did not notice anything unusual or feel any kind of eyestrain or discomfort while using the new ELs.
Click to expand...

Thats good news then .

keep up the updates John :t:
 
John Finnan said:
Yes, I like them very much and I've already found a buyer for my original pair.

No, I didn't notice the rolling ball effect when I used them yesterday and then I tried them again today for the purpose of looking specifically for it but I still did not notice anything unusual or feel any kind of eyestrain or discomfort while using the new ELs.
Click to expand...

If at first you don't succeed ... forget it! :t:
 
brocknroller said:
May the Irish hills caress y'an.
May her lakes and rivers bless y'an.
May the luck of the Irish enfold y'an.
May ya be blessed with the eyes of Finnan.
Click to expand...
"And may the curse of Katty Barry and her fourteen blind illegitimate children chase you so far over the hills of damnation that the Lord himself can´t find you with a telescope".
I don´t really mean this, of course, but I read it somewhere years ago. It didn´t mention if the Lord´s telescope is a Swarovski HD ATM with the new 25-50x zoom. But I imagine his binoculars may soon be Swarovisions (if those guys in Austria can ship out a few more pairs...)
 
I tried a pair of new 10x42 ELs today and compared them aganist my old 10*42 ELs (slow focus type). In comparison they are slightly brighter, a more blue hue to the image, reduced CA but i get very little with my current pair, but you do get the 'rolling world' feeling when panning which is strange and i am not sure i would get used to it. To upgrade it would cost me approx £1200 on top of the part exchange of my existing 10X42 ELs which is a lot of money for this very small improvement, especially when you consider I purchased a pair of 8X32 Els for £800 24 months ago!!
 
brocknroller said:
Here are geometric illustrations of what Clay described above:
http://www.arielnet.com/Main/images/fig1f.gif

Technically, this is actually an illustration of barrel distortion in a lens, which is a true distortion like pincushion, but lack of pincushion produces a very similar perceptual effect in optics.

Holger Merlitz uses moving images in his technical report to illustrate the the "globe effect" (his name for "rolling ball") that illustrate closer to what you actually see (if you see it!).

http://www.holgermerlitz.de/globe/distortion.html

The upside to "rolling ball" is that the images in the center field look even larger than normal. Given that roof prisms give a larger image scale than comparable magnification porros to begin with due to their close set barrels, the image scale through the 10x42 LX/LX L was huge in the center.

Unfortunately, the image scale became smaller at the edges (or to use the technical jargon - "squished").

It's this imbalance between the inside and outside image scale that gives the impression of the image scrolling over a ball, and when you move the bin, you get a "rolling ball".

Even the night sky looked like curved like Ptolemy's Crystalline Spheres through the LX L.

Some manufacturers can give you too much of a good thing by adding too much pincushion.

Then the views look like this:
http://upload.wikimedia.org/wikipedia/en/9/97/Pincushion-distortion.jpg

When I looked at my computer screen with the ZR 7x36 ED2, it had a saddle shape appearance.

Fortunately, while panning at longer distances, the pincushion wasn't distracting like "rolling ball," but I have used bins with too much pincushion that produced an inverse "rolling ball" while panning, for example, the 10x42 Swift Ultralite and the Swift 8x44 ED Ultralite.

The good news is that some people who initially see "rolling ball" eventually adapt to it.

So if you are not sure how you react to "rolling ball," order your SV EL from a store with a liberal return period so you have time to see if you can adapt to it.
Click to expand...

Dr. Brocknroller:

Nice rundown and useful links that sure help explain the situation.

Now if you were stranded on a desert island, with only one bin, which would be your choice? ;)
Jerry
 
Peak Birder said:
I tried a pair of new 10x42 ELs today and compared them aganist my old 10*42 ELs (slow focus type). In comparison they are slightly brighter, a more blue hue to the image, reduced CA but i get very little with my current pair, but you do get the 'rolling world' feeling when panning which is strange and i am not sure i would get used to it. To upgrade it would cost me approx £1200 on top of the part exchange of my existing 10X42 ELs which is a lot of money for this very small improvement, especially when you consider I purchased a pair of 8X32 Els for £800 24 months ago!!
Click to expand...

A flat field without distortion is not possible without the rolling ball effect, so I am not surprised.

Panning is rather common among birders, so the rolling ball effect will be quite evident for them. As far as I know, about 50 percent of all binocular users ( birders included ) are sensitive to the rolling ball effect, so I cannot understand, why Swarovski did choose this optical design for the new ELs.

A small amount of distortion at the edge of the field would be far less unpleasant for many birders.

Manfred
 
Last edited:
Peak Birder said:
I tried a pair of new 10x42 ELs today and compared them aganist my old 10*42 ELs (slow focus type). In comparison they are slightly brighter, a more blue hue to the image, reduced CA but i get very little with my current pair, but you do get the 'rolling world' feeling when panning which is strange and i am not sure i would get used to it. To upgrade it would cost me approx £1200 on top of the part exchange of my existing 10X42 ELs which is a lot of money for this very small improvement, especially when you consider I purchased a pair of 8X32 Els for £800 24 months ago!!
Click to expand...

I'm struggling to find any demo models in NW England which is frustrating because I'm really keen to have a look through a pair! I'm still weighing up whether I will actually buy a pair since I would prefer 8x32s with Swarovision - has anybody got any idea if it's going to be rolled out to the whole range or not?

Cheers

James
 
jsherrington said:
I'm struggling to find any demo models in NW England which is frustrating because I'm really keen to have a look through a pair! I'm still weighing up whether I will actually buy a pair since I would prefer 8x32s with Swarovision - has anybody got any idea if it's going to be rolled out to the whole range or not?

Cheers

James
Click to expand...

hello and welcome to the forum James.

have you tried Wilkinson cameras of preston ? , if they dont have them at the moment they will soon i'm sure . You can also try In-focus at Martin-mere at ormskirk .

hope this helps...:t:
 
Hi Manni,

I'm not aware of even anecdotal evidence that field flatness is related to the globe effect. Are you? It seems to be related to the amount of distortion in the optical system, as discussed in Holger Merlitz' papers.

Being a task induced phenomenon, however, we really need to examine why some people report the effect and others don't. For starters, there are several dynamic visual sub-tasks involved in birding that probably should be differentiated, and which might or might not induce some form of disorientation, — possibly due to the globe effect. (Note that disorientation may be induced by several other factors.) Does "panning" involve/exclude visual search or is it simply any lateral movement of the head? Does it involve/exclude visual tracking of an identified target? Does that matter? To what extent is the perceptual effect dependent on particular textural characteristics of the visual field? For example, is panning through foliage equivalent to panning a forest, a cityscape, a distant mountain ridge, or the night sky?

Globe effect demonstrations utilize an idealized but largely unrealistic field texture. How many of us really live in a two-dimensional checkerboard world that we observe passively? The paradigm is designed to isolate variables for modeling and scientific understanding, but we should exercise caution in generalizing too far. It's a big leap, after all, from that passive checkerboard world to the highly complex 3-D environment involving visual search and dynamic tracking that the birder lives in. Perceptual effects do not parse easily, and visually induced perceptions almost always involve the individual's oculomotor system, which has not even been discussed.

Anyway, it's just a few ideas to consider. At this point I'm neutral about the wisdom of Swaro's design approach, but, whatever else, it's gotta be interesting. ;)

Ed
 
Last edited:
Ed: as Holger's animations show the globe effect without head movement (by moving the field with the appropriate distortions. Of course there could be others effects too but this is a mostly visual effect (and perhaps a peripheral visual effect?).

I'm also on the side of flat field being a different issue from pincushion distortion as other bins makers (e.g. Nikon) show. I'm not sure I buy that.

But it is an interesting choice for Swaro to make. I'm curious what users will make of it.
 
Manni's correct.

If you correct your view to make a "flat field" any panning or movement will bring on the "rolling ball". You guys ever look through a 10mm SLR lens (not a fish eye). Move or pan it and you'll see how the field does not move gracefully across. It almost looks like the correction makes the field opposite of a fish eye lens (which makes sense).

Some manufacturers who claim to have a "flat field" apply a little pincushion so that the "rolling ball" is minimized. Meopta does this well. Wide... with no "rolling ball"

Swarovski is making a design decision that puts emphasis on the static view rather than a panning view. I'll bet money that they calculated the percent of time a birder or hunter pans vs static view.

I really want to get my hands on a pair and see for myself. But I gotta think if some say its there in a big way... it could turn a good percentage of people away.

Cheers
 
Last edited:
Oleaf,

Although Manni can clarify what he really meant, my interpretation of:
...A flat field without distortion is not possible without the rolling ball effect, ...
Click to expand...
is that that the combination of a flat field and no distortion necessarily results in a rolling ball effect. To repeat, I'm not aware that field curvature is involved with the globe illusion at all, but I'm willing to learn.

However, you made a much stronger statement:
...If you correct your view to make a "flat field" any panning or movement will bring on the "rolling ball".
Click to expand...
I don't know of any studies or anecdotal evidence showing such a causal relationship between field curvature and the globe effect. As an illustration, my 8x32 SEs, which have a flat field, produce no more globe effect that my 8x30 SLCs, which have significant field curvature. They both have about the same amount of distortion, however.

Kevin,

I believe Holger's animations are meant to simulate the effect of a person moving his/her head in a stationary environment (as is usually the case barring earthquakes, and so forth. ;)) Image motion on the retina is the same, so the rolling ball illusion is expected to be the same. That part is fine. However, real world tasks involving head motion are typically initiated by the observer, not the experimenter, and motivated by target search or tracking objectives. So it's unclear how much the globe effect (illusion) would be perceived under these real world conditions. The paradigm simply doesn't address that issue, and it is entirely possible that birders might not be hampered by it. Swarovski probably made such an assessment and took that design gamble. IMO, it's much better gamble than Leica took several years ago by way of exaggerating distortion in the BA and BN series. There you may not have seen much rolling ball, but there sure was a hellova lot of distortion. :eek!:

Ed
 
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Short update. I was told by the dealer that Swarovision was coming to the 8x32s but a lot later. Also he was saying that current pricing is introductory and future re-stocking orders would be aprrox £100 more!
 
elkcub said:
Oleaf,

Although Manni can clarify what he really meant, my interpretation of:

is that that the combination of a flat field and no distortion necessarily results in a rolling ball effect. To repeat, I'm not aware that field curvature is involved with the globe illusion at all, but I'm willing to learn.

However, you made a much stronger statement:

I don't know of any studies or anecdotal evidence showing such a causal relationship between field curvature and the globe effect. As an illustration, my 8x32 SEs, which have a flat field, produce no more globe effect that my 8x30 SLCs, which have significant field curvature. They both have about the same amount of distortion, however.

Kevin,

I believe Holger's animations are meant to simulate the effect of a person moving his/her head in a stationary environment (as is usually the case barring earthquakes, and so forth. ;)) Image motion on the retina is the same, so the rolling ball illusion is expected to be the same. That part is fine. However, real world tasks involving head motion are typically initiated by the observer, not the experimenter, and motivated by target search or tracking objectives. So it's unclear how much the globe effect (illusion) would be perceived under these real world conditions. The paradigm simply doesn't address that issue, and it is entirely possible that birders might not be hampered by it. Swarovski probably made such an assessment and took that design gamble. IMO, it's much better gamble than Leica took several years ago by way of exaggerating distortion in the BA and BN series. There you may not have seen much rolling ball, but there sure was a hellova lot of distortion. :eek!:

Ed
Click to expand...

A flat field without the rolling ball is possible. But in that case, the binocular must have some pincushion distortion, straight lines at the edge of the field will become curved, a neglectible drawback for birding imo.


Manfred
 
Last edited:
Peak Birder said:
Short update. I was told by the dealer that Swarovision was coming to the 8x32s but a lot later. Also he was saying that current pricing is introductory and future re-stocking orders would be aprrox £100 more!
Click to expand...

Thanks Ingle1970 and Peak Birder for your replies. Good to hear 8x32s will follow eventually - gives me more time to save up!

I'll definitely check out the 8.5x42 in the meantime - I tried In Focus at Martin Mere yesterday but they said they would only get them in on special order. Wilkinson Cameras didn't have them last time I checked (I live in Preston) but I've found that the field testing facilities aren't that great in the shopping centre!

Thanks again for your help - I'll post my thoughts once I get my hands on a pair.

Cheers

James
 
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