oetzi
Well-known member
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Porro or Roof ? Your choice. (2 Viewers)
- Thread starter Simon S
- Start date
Hubbies, please don't imitate what I suggested above! This was only given as a deterrent example on how the Papilios could work to come at closest distance to Absolute Zero regarding WAK for our beloved hobby.
Next time I'll tell you how I watched the Christmas tree with binoculars and what my better half has to say about it. But for now, I don't want to complicate a difficult matter even more.
Steve
P.S. Annabeth, you won't tell my wife, what I've written here, do you?
Next time I'll tell you how I watched the Christmas tree with binoculars and what my better half has to say about it. But for now, I don't want to complicate a difficult matter even more.
Steve
P.S. Annabeth, you won't tell my wife, what I've written here, do you?
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A2GG
Beth
Now there's a first ...
henry link
Well-known member
Though I'd add a little more on the subject of "3-D" in roofs vs. Porros.
Imagine looking at two objects through 10x binoculars. One object is 80' away and the other, just behind the first is 160' away. The triangles produced by the baseline of the objective lenses of an inline roof prism binocular and the lines drawn to the objects are exactly the same as they would be for unaided eyes if the objects were at 8' and 16', directly correlating with the magnification factor. Through a Porro, with objectives spaced twice as far apart as the eyes, the triangles would be the same as unaided eyes at 4' and 8', twice the magnification factor. I know which one of these shows more stereopsis, but which one should be called more "natural" or "realistic"?
Imagine looking at two objects through 10x binoculars. One object is 80' away and the other, just behind the first is 160' away. The triangles produced by the baseline of the objective lenses of an inline roof prism binocular and the lines drawn to the objects are exactly the same as they would be for unaided eyes if the objects were at 8' and 16', directly correlating with the magnification factor. Through a Porro, with objectives spaced twice as far apart as the eyes, the triangles would be the same as unaided eyes at 4' and 8', twice the magnification factor. I know which one of these shows more stereopsis, but which one should be called more "natural" or "realistic"?
I will stick my uneducated head above the parapet and risk stating that the Porro view must by definition be unrealistic, based as it is on an unnaturally wide pseudo-spacing of the eyes.
On the other hand magnifying one's vision by 8x or 10x can hardly be called naturalistic either.
Don't groan too much but could Zeiss's A-K prisms give a better compromise given the small amount of off-set of the objectives vs the eyepieces?
Lee
Henry, good point. I assume you think that the enhanced 3-D-effect given by porros isn't as natural as the view through roofs because natural perception with naked eyes isn't based upon that wider IPD. This argument is pretty along the lines we had with colour reproduction. In theory the reproduction of colours should be the most natural or realistic one, that doesn't change the balance among the wavelengths. With other chosen balances one might get some requested effects (e.g. better view at dawn etc.). But the result of these changes would be different from natural view and thus differs from perceptional 'truth'.
@OP: The discussion of roof vs. porros is a bit dated in my opinion. So I'd like to throw in some new thoughts into that somewhat old debate. If somebody asks me if I prefer porro or roof I would, answer no special preference here. I would always choose the instrument of the better optical performance, no matter of the type of prisms used. So I'm rather interested on the question what could be the reasons of success for the roof in general.
I think people prefer instinctively the instrument that provides the most natural view. That includes the viewing direction. In nature the viewing direction and the central optical axis between viewed object and the eye's pupil are always in a line. From a subjective point of view a roof seems to provide exactly this, while the porro concept differs from that. Humans prefer things how they use to be because any anomaly comes at the price of additional energy consumption and a higher degree of complexity. Here comes into play what I was thinking about in that posting:
http://www.birdforum.net/showpost.php?p=2654659&postcount=865
With aesthetics and emotional or as one could say also subjective choices I meant something like how decision making of humans works. I know this leads a little bit too far, so quickly back on topic: The roof wins for two reasons. First they look more beautiful because of a higher degree of symmetry of their shape compared to porros. Second, the use is more natural because the viewing directing seems to be the same like viewing without binoculars.
If I'm correct with the stated above that means that roof would always win, even if the optics of porros are better. I think this could explain the success of roofs yet before the introduction of phase correction coatings, when the porros were still superior indeed.
Steve
@OP: The discussion of roof vs. porros is a bit dated in my opinion. So I'd like to throw in some new thoughts into that somewhat old debate. If somebody asks me if I prefer porro or roof I would, answer no special preference here. I would always choose the instrument of the better optical performance, no matter of the type of prisms used. So I'm rather interested on the question what could be the reasons of success for the roof in general.
I think people prefer instinctively the instrument that provides the most natural view. That includes the viewing direction. In nature the viewing direction and the central optical axis between viewed object and the eye's pupil are always in a line. From a subjective point of view a roof seems to provide exactly this, while the porro concept differs from that. Humans prefer things how they use to be because any anomaly comes at the price of additional energy consumption and a higher degree of complexity. Here comes into play what I was thinking about in that posting:
http://www.birdforum.net/showpost.php?p=2654659&postcount=865
With aesthetics and emotional or as one could say also subjective choices I meant something like how decision making of humans works. I know this leads a little bit too far, so quickly back on topic: The roof wins for two reasons. First they look more beautiful because of a higher degree of symmetry of their shape compared to porros. Second, the use is more natural because the viewing directing seems to be the same like viewing without binoculars.
If I'm correct with the stated above that means that roof would always win, even if the optics of porros are better. I think this could explain the success of roofs yet before the introduction of phase correction coatings, when the porros were still superior indeed.
Steve
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I'll add an observation about stereopsis in roof vs roof. It has already been mentioned in this thread that roofs differ in their objective offset also, and I just measured the two "alpha" roofs I happen to have for testing now. When set to my 66mm interpupillary distance, the Nikon EDG 8x42 has objective optical axes 68mm apart, and the Zeiss 8x42 Victory HT 74mm apart. This is just under 10% difference, and is visible as less pronounced depth perception in the Nikon. Treetops ca 150m away, in front of a forest some 500 meters back stood out better in the Zeiss.
Kimmo
Kimmo
Steve C
Well-known member
I understand the business about the off set objectives, but what I could never seem to get a good perceptual handle on is how that matters. After the light beam passes through the prism system, either porro or roof, the beam is then passed through the eyepiece/ocular lenses in a straight line to the eye. The oculars have to be matched through IPD settings to match the eyes of the viewer.
I agree with what Hinnark says above. I'll have to go check some of my roofs, but previous checking I've done makes me think I observed the same thing Kimmo posts about above.
I agree with what Hinnark says above. I'll have to go check some of my roofs, but previous checking I've done makes me think I observed the same thing Kimmo posts about above.
Henry's point about stereopsis is good, although it will hardly convince Porro fans that they are tolerating a bad situation. But while we're at it, let's examine how unnatural the magnified view is, at best.
Take his objects at 80' and 160' as the example again. We like to think that the binocular gives us a view that is just like we'd see if we walked over closer to the scene.
If we walk closer, so that we're now 1/10 as far from the closer object, that will be to a distance of 8", or 72' closer.
The more distant object will still be 88' away. But if it was viewed from the original location at 10x, its size would suggest that its distance had been shrunk from 160' to 16'.
88' and 16' are very different. Magnification alters perspective so that the separations between objects appears artificially compressed. Arguably, the unnatural 3-d enhancement could help restore some impression of depth to a scene that has had the depth sucked right out of it by magnification. Personally I feel that it only adds insult to injury.
Thank goodness, we get used to this stuff and worse, and smile thinking how natural the view in our own binocular looks, dealing also with eye positioning, field distortions, and focusing all in perfect stride, with a little practice. The brain is deadly efficient at ignoring stuff you don't want to see.
Yep, Porro fans must be crazy, what's wrong with them? The answer is, much worse things must be wrong with all of us!
Ron
Take his objects at 80' and 160' as the example again. We like to think that the binocular gives us a view that is just like we'd see if we walked over closer to the scene.
If we walk closer, so that we're now 1/10 as far from the closer object, that will be to a distance of 8", or 72' closer.
The more distant object will still be 88' away. But if it was viewed from the original location at 10x, its size would suggest that its distance had been shrunk from 160' to 16'.
88' and 16' are very different. Magnification alters perspective so that the separations between objects appears artificially compressed. Arguably, the unnatural 3-d enhancement could help restore some impression of depth to a scene that has had the depth sucked right out of it by magnification. Personally I feel that it only adds insult to injury.
Thank goodness, we get used to this stuff and worse, and smile thinking how natural the view in our own binocular looks, dealing also with eye positioning, field distortions, and focusing all in perfect stride, with a little practice. The brain is deadly efficient at ignoring stuff you don't want to see.
Yep, Porro fans must be crazy, what's wrong with them? The answer is, much worse things must be wrong with all of us!
Ron
henry link
Well-known member
Thanks Ron. I was going to use the very same example of walking up to the 8' from the 80' object, but I ran out of writing gas. Great minds, I guess. As soon as you put any pair of binoculars to your eyes the spacial relationship pooch is screwed.
I'll add one more measurement to Kimmo's. When the 8x56 Zeiss FL is set to his 66mm IPD the objective spacing is 82mm. That's probably the biggest dose of Porro like stereopsis available in a roof.
I'll add one more measurement to Kimmo's. When the 8x56 Zeiss FL is set to his 66mm IPD the objective spacing is 82mm. That's probably the biggest dose of Porro like stereopsis available in a roof.
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Regarding the difference in 3-D perception I have to assert that I see it instantly when switching from porro to roof or vice versa. But that impression use to fade soon. After a minute or so of continued use of a porro for example, I don't notice it anymore. The sensation of enhanced 3-d has disappeared then. The system of visual perception had, once more, proved its ability to adapt.
Steve
Steve
brocknroller
porromaniac
Good Grief! The only view that's "unnatural" about this discussion is removing the human eye and brain from the "equation". But it seems that's always the case when the experts start rolling the numbers.
Now if you want to bench test bins and post the results, that's all fine and dandy, and even informative and helpful in many cases, but when you start telling others what they are supposed to see through bins in the field, I draw the line in the snow (can't see the sand, it's encrusted).
I admit when I get my 8x EII down to 7 ft. that my eyes cross a bit but I compensate for the wider set barrels by reducing the IPD and I get no overlapping barrels, and the image is still sharp as a tack, I may lose something on "paper" but I certainly don't see it, and, let's face, at 7 ft. a bin's optics would have to be total crap for you not see good detail.
The 8x32 HG is more comfortable to use at that close distance, but at normal birding distance for me, it shows a 2-D compressed view that is anything but natural. Thoreau whatever numbers you want at that, but that won't change my perception or others who prefer the porro view as looking more natural.
Besides, how many of you actually get that close to a bird, let alone the 4-5 ft. close focus of modern roofs? Are you disguised like this?
http://images.yippy.com/search?input-form=clusty-simple&v%3Asources=images&v%3Aproject=clusty-images&query=Artie+Johnson+dressed+up+as+soldier
Or are you looking at your budgies inside the house?
The only birds that let me get that close to them are the chickadees in my backyard, who have no fear and even eat seeds out of my hand. Just don't let them sit on your head, they are not potty trained.
http://funnypicturesimages.com/fullscreen/placed-with-binoculars-looking-at-the-birds-head.html
I really can't understand this obsession with close focus. If you want to look at some faults with roofs (heaven forbid!), dig up the tradeoffs Holger has mentioned about close focusing bins and the issues he's had with the internal focus on his 8x32 FL.
Roofs have their advantages and porros have their advantages,and people may prefer one over the other for perceptual reasons for for ergonomic reasons, but to try to mathematically prove that roofs deliver a superior natural view is an exercise in futility, IMO.
<B>
Now if you want to bench test bins and post the results, that's all fine and dandy, and even informative and helpful in many cases, but when you start telling others what they are supposed to see through bins in the field, I draw the line in the snow (can't see the sand, it's encrusted).
I admit when I get my 8x EII down to 7 ft. that my eyes cross a bit but I compensate for the wider set barrels by reducing the IPD and I get no overlapping barrels, and the image is still sharp as a tack, I may lose something on "paper" but I certainly don't see it, and, let's face, at 7 ft. a bin's optics would have to be total crap for you not see good detail.
The 8x32 HG is more comfortable to use at that close distance, but at normal birding distance for me, it shows a 2-D compressed view that is anything but natural. Thoreau whatever numbers you want at that, but that won't change my perception or others who prefer the porro view as looking more natural.
Besides, how many of you actually get that close to a bird, let alone the 4-5 ft. close focus of modern roofs? Are you disguised like this?
http://images.yippy.com/search?input-form=clusty-simple&v%3Asources=images&v%3Aproject=clusty-images&query=Artie+Johnson+dressed+up+as+soldier
Or are you looking at your budgies inside the house?
The only birds that let me get that close to them are the chickadees in my backyard, who have no fear and even eat seeds out of my hand. Just don't let them sit on your head, they are not potty trained.
http://funnypicturesimages.com/fullscreen/placed-with-binoculars-looking-at-the-birds-head.html
I really can't understand this obsession with close focus. If you want to look at some faults with roofs (heaven forbid!), dig up the tradeoffs Holger has mentioned about close focusing bins and the issues he's had with the internal focus on his 8x32 FL.
Roofs have their advantages and porros have their advantages,and people may prefer one over the other for perceptual reasons for for ergonomic reasons, but to try to mathematically prove that roofs deliver a superior natural view is an exercise in futility, IMO.
<B>
To my eyes porro's still have a more realistic view than roofs. It's like trying to convince me mathematically that my eyes are lying.Good Grief! The only view that's "unnatural" about this discussion is removing the human eye and brain from the "equation". But it seems that's always the case when the experts start rolling the numbers.
Now if you want to bench test bins and post the results, that's all fine and dandy, and even informative and helpful in many cases, but when you start telling others what they are supposed to see through bins in the field, I draw the line in the snow (can't see the sand, it's encrusted).
I admit when I get my 8x EII down to 7 ft. that my eyes cross a bit but I compensate for the wider set barrels by reducing the IPD and I get no overlapping barrels, and the image is still sharp as a tack, I may lose something on "paper" but I certainly don't see it, and, let's face, at 7 ft. a bin's optics would have to be total crap for you not see good detail.
The 8x32 HG is more comfortable to use at that close distance, but at normal birding distance for me, it shows a 2-D compressed view that is anything but natural. Thoreau whatever numbers you want at that, but that won't change my perception or others who prefer the porro view as looking more natural.
Besides, how many of you actually get that close to a bird, let alone the 4-5 ft. close focus of modern roofs? Are you disguised like this?
http://images.yippy.com/search?input-form=clusty-simple&v%3Asources=images&v%3Aproject=clusty-images&query=Artie+Johnson+dressed+up+as+soldier
Or are you looking at your budgies inside the house?
The only birds that let me get that close to them are the chickadees in my backyard, who have no fear and even eat seeds out of my hand. Just don't let them sit on your head, they are not potty trained.
http://funnypicturesimages.com/fullscreen/placed-with-binoculars-looking-at-the-birds-head.html
I really can't understand this obsession with close focus. If you want to look at some faults with roofs (heaven forbid!), dig up the tradeoffs Holger has mentioned about close focusing bins and the issues he's had with the internal focus on his 8x32 FL.
Roofs have their advantages and porros have their advantages,and people may prefer one over the other for perceptual reasons for for ergonomic reasons, but to try to mathematically prove that roofs deliver a superior natural view is an exercise in futility, IMO.
<B>
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Chosun Juan
Given to Fly
Well, back on topic it seems ..... I believe this is the type of discussion Simon had in mind with the OP!
Kimmo, it is reassuring that you can detect this difference (well it makes sense to my mind anyway), as other reports between SP, and ABK prism types have been of no detectable difference.
The SP prisms have an entry /exit lightpath centreline that is exactly in line.
The ABK prisms have a slight offset, such that the entry centreline is greater than the exit centreline ....... in line (no pun!
) with your measurements. No as great as with a PorroI type, but your experience seems consistent with what I'd expect.Chosun :gh:
Chosun Juan
Given to Fly
Steve,
This is eminently logical!
I'd love to hear the mathematical explanation that circumvents? this ..... calling all mavens?
Chosun :gh:
Chosun Juan
Given to Fly
Ron,
Emminently sensible .....
but what does that mean? that I can't believe a damn thing my eyes see?
or that I should believe everything they see, as they've already cleaned up the view for me while I wasn't watching?!!
Chosun :gh:
Chosun Juan
Given to Fly
Brock !
Whoooooooweeeee ..... !!
You just know that one's going to come back and bite you !!! 8-P
Can we quote you on that ....... ?
:-O Chosun :gh:
elkcub
Silicon Valley, California
Good Grief! The only view that's "unnatural" about this discussion is removing the human eye and brain from the "equation". But it seems that's always the case when the experts start rolling the numbers.
Now if you want to bench test bins and post the results, that's all fine and dandy, and even informative and helpful in many cases, but when you start telling others what they are supposed to see through bins in the field, I draw the line in the snow (can't see the sand, it's encrusted).
I admit when I get my 8x EII down to 7 ft. that my eyes cross a bit but I compensate for the wider set barrels by reducing the IPD and I get no overlapping barrels, and the image is still sharp as a tack, I may lose something on "paper" but I certainly don't see it, and, let's face, at 7 ft. a bin's optics would have to be total crap for you not see good detail.
The 8x32 HG is more comfortable to use at that close distance, but at normal birding distance for me, it shows a 2-D compressed view that is anything but natural. Thoreau whatever numbers you want at that, but that won't change my perception or others who prefer the porro view as looking more natural.
Besides, how many of you actually get that close to a bird, let alone the 4-5 ft. close focus of modern roofs? Are you disguised like this?
http://images.yippy.com/search?input-form=clusty-simple&v%3Asources=images&v%3Aproject=clusty-images&query=Artie+Johnson+dressed+up+as+soldier
Or are you looking at your budgies inside the house?
The only birds that let me get that close to them are the chickadees in my backyard, who have no fear and even eat seeds out of my hand. Just don't let them sit on your head, they are not potty trained.
http://funnypicturesimages.com/fullscreen/placed-with-binoculars-looking-at-the-birds-head.html
I really can't understand this obsession with close focus. If you want to look at some faults with roofs (heaven forbid!), dig up the tradeoffs Holger has mentioned about close focusing bins and the issues he's had with the internal focus on his 8x32 FL.
Roofs have their advantages and porros have their advantages,and people may prefer one over the other for perceptual reasons for for ergonomic reasons, but to try to mathematically prove that roofs deliver a superior natural view is an exercise in futility, IMO.
<B>
Hi Brock,
I may have missed it, but I didn't read anyone on this thread saying one view is more "natural" than the other, ... and I thought Ronh summarized several notions rather well, although I might not subscribe to them all:
Judging by the fact that stereo binoculars were used during the European trench wars, presumably with good effect to improve distance estimation, I'm not persuaded that "insult is added to injury" by the larger stereo base afforded by Porros. Both Henry and Kimmo also appear to acknowledge the improvement to roof views with larger objective separations. So, ... no issue?
Frankly, I'm happily torn between my two favorites: (a) the 8.4x44 Swift 804ED, and (b) the Swaro 8x42 SLC HD. Vive la difference!
Ed
