kristoffer
Used Register
So those (probably quite alot of ppl, some don´t bother with optics and just pick what looks best and sticks with it for 15 years) who buy the Swarovision without trying can get a nasty surprise. Or a pleasant one 
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swarovision EL (1 Viewer)
- Thread starter Ingle1970
- Start date
Elkcub,
I think your getting some things mixed up here but I'm not the one to straighten it out. Go look through a SLR wide lens (say a 10-14mm) and pan around. You'll get a big dose of what "rolling ball" is. Since a SLR takes static shots... rolling ball doesn't matter. But... the wide lens is "corrected" to make the scene look flat. It's not flat... the outside of the view is actually curved away from you.
There's no binocular with a truly "flat" corrected view... you couldn't pan without getting sick.
Go grab a SLR camera with a super wide lens (not a fish eye as those are not corrected)
Cheers
Ingle1970
Well-known member
you could "buy" a pair from In-focus , then you have plenty of time to evaluate them in the 2 week approval period , then return them .
elkcub
Silicon Valley, California
Dear Oleaf,
Let me give it one more try. Here is the abstract from Holger Merlitz' paper published by the Optical Society of America. If you find any reference to field curvature, either here or in the main article, please point it out. The title is "Distortion of binoculars revisited: Does the sweet spot exist?" (The "sweet spot," incidentally, is not what most people refer to by that term, but rather a narrow range for an optimizing parameter.)
If after reading this you believe that panning with a wide-angle SLR produces the same globe illusion, particularly because its corrected for field curvature, that is entirely up to you. Forgive me, but I find it amusing that you also think I've got "some things mixed up."
Your statement:
appears to be the basis for an insightful publication all of its own.
Cheers,
Ed
kristoffer
Used Register
Birdforums optics department at it´s best
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elkcub
Silicon Valley, California
Hi Pablo,
In a few words, this Wiki article does a good job. http://en.wikipedia.org/wiki/Globe_effect
The effect is an optical illusion associated with a panning movement. Strictly speaking it falls in the domain of visual psychophysics, i.e., the intersection of psychology and optical physics. Hemholtz was one of the fathers of the subject. http://en.wikipedia.org/wiki/Hermann_von_Helmholtz
Ed
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Ed,
At the risk of seeming impertinent here, which I assure you I am not; is there any way of determining in the domain of visual psychophysics what percent of the discipline is psychology and what percent is solid physics? My oldest son is in a graduate program working on his PhD in Physics and I'm not sure he has even heard of this field, but I will check with him tomorrow.
Cordially,
Bob
At the risk of seeming impertinent here, which I assure you I am not; is there any way of determining in the domain of visual psychophysics what percent of the discipline is psychology and what percent is solid physics? My oldest son is in a graduate program working on his PhD in Physics and I'm not sure he has even heard of this field, but I will check with him tomorrow.
Cordially,
Bob
elkcub
Silicon Valley, California
Actually, that's a very good question, but hard to answer concisely.
Back in the 19th Century academics were not divided up quite like they are today. Hemholtz, for example, was a renaissance man in the true sense, being a philosopher, mathematician, physicist, physiologist, and sensory psychologist all in one. Some geniuses like that exist in modern times, for example, Thomas Gold, http://en.wikipedia.org/wiki/Thomas_Gold, whose major contributions spanned physics, astronomy, engineering, and sensory psychology. Gold made notable contributions to auditory psychophysics.
Nowadays, I would say that most psychophysicists have strong backgrounds in engineering or physics, possibly to a Masters level. Some great mathematicians, such as R. Duncan Luce http://en.wikipedia.org/wiki/R._Duncan_Luce chose to dedicate their careers to psychology and psychophysics.
Overall, every experimental psychologist has training in psychophysics, but the strength of their physics and engineering backgrounds vary. I expect that most pure physicists don't get much if any exposure to psychophysics in their curriculum, but later may choose to apply themselves in that field. They are often standouts. Mathematics, of course, is the underpinning of it all, altho psychology emphasizes statistics and physics emphasizes calculus.
As percentages go, the psychology/physics split is probably proportional to the growth path of the individual researcher. Sorry to provide such a muddled response.
Anyway, congratulations on having a Ph.D. on the way (and a potential psychophysicist.) :t:
Ed
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elkcub
Silicon Valley, California
Thanks for taking the time to answer this, Ed. It is concise enough and certainly not muddled. I've e-mailed this to my son and am looking forward to hearing his "take" on it.
Bob
Runaround
Hanging In There
I'll skip all the theory and speak up as someone who has actually used them in the field. I spent all weekend birding. These are amazing binoculars and I'm very happy with them. Was the rolling globe effect noticeable? Only on one occasion. I was at a site where I had a clear view of the horizon. If I panned quickly, faster than what would be appropriate for birding, the effect was noticeable. If I panned more slowly or followed birds in flight, I did not notice the effect.
hgalbraith
Well-known member
new 10x42 swarovision ELs
I received a pair of 10x42s a week or so ago and have been using them in the field since then. I have been having trouble finding 10s that suited my eyes - probably something do do with my ageing eyes being unable to cope with the combination of shallow dof and the rapid focus of most modern bins. Tried Zeiss FLs and they did not work for me, then tried Nikons - just as bad. However, i am glad to say that the new ELs suit my eyes well and I have no trouble using them.
Initial thoughts:
handling - much better than the original ELs which I found to be too "fat" and did not fit my hands well. The new bins are slimmed down a little - enough to fit my hands really comfortably. The balance is superb. Speed of focus seems to be just right for me.
Optics - could anything be any sharper? The sharp definition from edge to edge is a sight to behold. No hint of CA (at least to my eyes), and very bright (for a 10x) under a variety of field conditions.
Rolling ball - not a problem. I do not notice it when panning unless I force myself to look for it. I guess that if this is the small price that you pay for lack of edge distortion then it is a bargain (IMO).
I received a pair of 10x42s a week or so ago and have been using them in the field since then. I have been having trouble finding 10s that suited my eyes - probably something do do with my ageing eyes being unable to cope with the combination of shallow dof and the rapid focus of most modern bins. Tried Zeiss FLs and they did not work for me, then tried Nikons - just as bad. However, i am glad to say that the new ELs suit my eyes well and I have no trouble using them.
Initial thoughts:
handling - much better than the original ELs which I found to be too "fat" and did not fit my hands well. The new bins are slimmed down a little - enough to fit my hands really comfortably. The balance is superb. Speed of focus seems to be just right for me.
Optics - could anything be any sharper? The sharp definition from edge to edge is a sight to behold. No hint of CA (at least to my eyes), and very bright (for a 10x) under a variety of field conditions.
Rolling ball - not a problem. I do not notice it when panning unless I force myself to look for it. I guess that if this is the small price that you pay for lack of edge distortion then it is a bargain (IMO).
elkcub
Silicon Valley, California
Thanks, that's excellent feedback and quite consistent with what one might expect (in theory
). See post #34, "... 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." So, in assessing these new binoculars it will come down to: (1) the viewing environment, (2) passive vs. active observer involvement, and (3) movement speeds. As you have done, we should make an effort to report these along with simply the presence or absence of the effect.
Ed
John M Robinson
Well-known member
How do the 8x32 Nikon SE and 8x42 Ultravid BR fare in the "rolling ball" department? I thought I noticed it with my Ultravids one time when panning along a mountain ridge. I don't do a lot of panning along a horizon line so it isn't a big issue to me, but I did notice it that time.
John
John
Kevin Purcell
Well-known member
I don't see rolling ball with my 8x32 or 10x42 Nikon SE. In fact the only bin I see "distortion" on the way to rolling ball but not quite full on rolling ball is my Swift Eaglet 7x36.
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