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Which roofs are better for their 3D view? (1 Viewer)

Hi Ed,
I have asked the question of whether the angle difference between the rays hitting the left and right side of a single eye pupil is enough to account for the stereo image I see with an object at two feet distance, or whether perception or something else explains the image that I see.

Hopefully, my colleague can enlighten me, and come up with a likely explanation.
 
Hi Ed,
I have asked the question of whether the angle difference between the rays hitting the left and right side of a single eye pupil is enough to account for the stereo image I see with an object at two feet distance, or whether perception or something else explains the image that I see.

IMHO, the various light ray angles hitting the retina allows our brain to directly interpret real-time orientations (top-bottom-right-left). Due to personal perceptions and life experiences, those familiar spacial clues we all have in memory, keys our senses and feelings of depth to the what we see with one eye...basically, a pseudo 3D! :eek!:

Add the 2nd eye (slowly getting there) and hopefully, I'll be back looking at the real world in 3D!! ;)

Ted
 
Thanks Theo and Pileatus.

The reference in post 43 does not explain how I see 3D at 2 feet distance with one eye without head movement.
There could be eye movement, but minimal I think.
The other explanation could be accommodation but I have very little, or depth of focus.

I will see if my friend thinks that the angular difference can be the cause with one eye seeing 3D.
 

Yes, John: THANKS!

180515

These are the kinds of conversations that are valuable to any similar forum.

My oldest son was born with severe strabismus. When he was a year old, he went under the knife of Zane Pollard of Atlanta, one of the nation’s top ophthalmological surgeons. Debbie and I had to trust him, although he was a young man with only 19 degrees, certificates, and awards on his wall. Zane corrected his strabismus to 7 degrees. The assumption was that, after a time, the brain would compensate.

It has been proven in college experiments that students fitted with prismatic eyeglasses, which would invert their vision, would, in a few hours, have their view righted by a brain that did not want to play the game. Then, within a few hours of the experiment being concluded, their vision—with the discarding of those glasses—would be returned to normal.

Sometime later, as I wondered about his ability to play sports—primarily baseball—another ophthalmic surgeon (shoot me now, I can’t remember his name*) told me while he was developing the proper perception, the brain would work as follows:

Subconsciously, he knows a baseball is x inches in diameter. As the ball is approaching him appearing .5 inches, .75 inches, 1.5 inches, 2 inches diameter, etc. (all within a tiny fraction of a second) those rapid-fire cues will tell him when to raise his glove and in which location.

A hundred year from now, our time could easily be seen as we see the “blood-letting” of the past as being a valuable medical procedure, for I have no doubt that as often as not what we THINK we know ... we don’t. Each generation of scientist seems to prove a large portion of the previous generation of scientists to have been in error.

“Any man whose errors take ten years to correct is quite a man.”— Dr. J. Robert Oppenheimer

* Please don’t quote that. A “fact” without a verifiable source is just a personal whim, notion, or opinion.

Bill
 
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Yes, John: THANKS!

180515

These are the kinds of conversations that are valuable to any similar forum.

My oldest son was born with severe strabismus. When he was a year old, he went under the knife of Zane Pollard of Atlanta, one of the nation’s top ophthalmological surgeons. Debbie and I had to trust him, although he was a young man with only 19 degrees, certificates, and awards on his wall. Zane corrected his strabismus to 7 degrees. The assumption was that, after a time, the brain would compensate.

It has been proven in college experiments that students fitted with prismatic eyeglasses, which would invert their vision, would, in a few hours, have their view righted by a brain that did not want to play the game. Then, within a few hours of the experiment being concluded, their vision—with the discarding of those glasses—would be returned to normal.

Sometime later, as I wondered about his ability to play sports—primarily baseball—another ophthalmic surgeon (shoot me now, I can’t remember his name*) told me while he was developing the proper perception, the brain would work as follows:

Subconsciously, he knows a baseball is x inches in diameter. As the ball is approaching him appearing .5 inches, .75 inches, 1.5 inches, 2 inches diameter, etc. (all within a tiny fraction of a second) those rapid-fire cues will tell him when to raise his glove and in which location.

A hundred year from now, our time could easily be seen as we see the “blood-letting” of the past as being a valuable medical procedure, for I have no doubt that as often as not what we THINK we know ... we don’t. Each generation of scientist seems to prove a large portion of the previous generation of scientists to have been in error.

“Any man whose errors take ten years to correct is quite a man.”— Dr. J. Robert Oppenheimer

* Please don’t quote that. A “fact” without a verifiable source is just a personal whim, notion, or opinion.

Bill

If it's a science it's never settled. If it's settled it's never a science.

Ed
 
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I got a very long typically thoughtful reply from the optics lecturer.
No firm conclusions, but he suggests.

Seeing stereo close up with one eye may be due to perspective changes.
Also photographs taken with large aperture single lenses show interesting effects.

He came up with the view of a 2D photo being better with one eye than two without seeing the photo of Gibson above.

He agrees that magnification with roof prism binoculars enhances the stereo effect by the magnification, but he suggests one considers that the object looked at has been moved 8x nearer with an 8x roof prism binocular. We are seeing stereo effects of the object as if it was 8x nearer.

He has the Papillio and is fascinated by it.

He suggests that views with Porroprism binoculars is more like looking at models, both wide objective spacing and reverse smaller objective spacing.

He has a Donkey's ears binocular, which is fascinating.
Is anybody able to work on collimating one of these at an affordable price?

He says there is a lot that we don't yet understand.

Monocular clues he thinks are built into our DNA.

I must reread carefully.

What I see with one eye is stereo close up, say 2 feet to 10 feet, but no stereo at 10 yards plus with one eye, so this monocular stereo effect is distance related.
I do not see stereo at a distance with one eye.

As far as binoculars.
The formula with a tripod mounted binocular is I think, with appropriate units.
Magnification times objective spacing times 1/distance to target compared with a very distant background times visual acuity.
With unaided eyes the magnification is about 1x depending on whether glasses are worn.

So with an 8x roof prism binocular the stereo effect is around 8x or 9x unaided eyes.

With an 8x Porroprism binocular with 2x IPD objective spacing, about 16x.

With an 8x reverse Porroprism binocular about 5x.

So yes a Porroprism binocular does show enhanced stereo, but magnification dominates, not objective spacing.
 
So yes a Porroprism binocular does show enhanced stereo, but magnification dominates, not objective spacing.

The most recent article in question illustrates there are a number of factors at work in attaining stereopsis OR THE PERCEPTION OF STEREOPSIS, that differ from person to person. I have no problem bringing out the 3D image from most of the “hidden image” settings on a seemingly random and meaningless background (see attached). My wife is an intelligent school teacher, but she has never been able to do it at all. It is plain there is much at work here to cause the opto-geeky to take pause.

Even so, I would caution those with a sincere interest not to sell out so quickly on the importance of objective space as a major contributor to the 3d effect in binoculars—at short distances. In both coincidence and stereoscopic rangefinders (https://en.wikipedia.org/wiki/Coincidence_rangefinder) this separation plays an integral part. Were it not so, the rangefinders on our last battleships would not need to be expensive, complex 44-foot instruments. Two pencils, two pieces of paper, two observers, each with a telescope alidade or azimuth circle, could do the work—geometric principles being what they are—but by the time they worked it out, they might need to be a good ... swimmer. :cat:

Just a thought,

Bill
 

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Thanks Bill, I have to support that statement. This morning I took the SE 8X32 and a Leica 8X42 HD and viewed some branches in my back yard the distance is ~ 60 feet away. While there is some obvious spatial 3-D with the Leica with branches 6 inches to a foot apart at that distance, other thin branches closer together 2-3 inches, blend in with view. With the SE I am able to easily distinguish the 3-D view with these small diameter branches 2 inches apart. I have always appreciated this feature of the porro design, and I can spot small critters in the bush easier than any roof. One of my friends who is a hunter uses Docter 8X56 and 10X56 porros, he says the same thing regarding porros, many of his friends switched to roofs simply for the lighter weight and smaller dimensions, not for the better view.

Andy W.
 
Hello Andy,

Roof prism binoculars were never about a better view; they were popular for compactness and weight. With the possible exception of close focussing, there is no reason for a Porro to be optically inferior to a roof. Until the advent of phase coating, the roof prism binoculars were optically inferior, in contrast and in resolution.

Happy bird watching,
Arthur
 
Thanks Bill, I have to support that statement. This morning I took the SE 8X32 and a Leica 8X42 HD and viewed some branches in my back yard the distance is ~ 60 feet away. While there is some obvious spatial 3-D with the Leica with branches 6 inches to a foot apart at that distance, other thin branches closer together 2-3 inches, blend in with view. With the SE I am able to easily distinguish the 3-D view with these small diameter branches 2 inches apart. I have always appreciated this feature of the porro design, and I can spot small critters in the bush easier than any roof. One of my friends who is a hunter uses Docter 8X56 and 10X56 porros, he says the same thing regarding porros, many of his friends switched to roofs simply for the lighter weight and smaller dimensions, not for the better view.

Andy W.

Thank, Andy:

I’m totally onboard with your observations. However, just remember others may not be; the best shrink in the world is at a loss when trying to reason what is going on between someone’s ears. I once saw an “idiot savant” tested for his ability to be given ANY DATE of ANY YEAR of ANY CENTURY and without hesitation tell you what day of the week it was—based on our calendar—with 100% accuracy. We are only beginning to understand man’s potential.

To err is human; to really foul things up requires a computer. :cat:

Bill
 
Hello Andy,

Roof prism binoculars were never about a better view; they were popular for compactness and weight. With the possible exception of close focussing, there is no reason for a Porro to be optically inferior to a roof. Until the advent of phase coating, the roof prism binoculars were optically inferior, in contrast and in resolution.

Happy bird watching,
Arthur

AMEN!

Bill
 
With a 6 yard baseline and 28x magnification, the baseline is about 90 times an average IPD.
Here the objective spacing has more contribution than the magnification.
Of course these naval rangefinders have very large components from both the objective spacing and magnification.

Another interesting variant is the long distance rangefinder that uses the curvature of the earth as the means of distance measure.
The operating height of the instrument is known. The target ship is identified and the size and height above sea level is known, so it is fairly simple to work out the distance by how high above the horizon the control station of the target ship seems to be.

Using, say 8x binoculars, a Porroprism binocular with the wider objective spacing compared to a roof prism binocular will give twice as much stereo effect.
Of course this is significant.
But both bring things 8x closer and this magnification has more effect than the two times due to the wider Porroprism objective spacing.
Hand held the magnification contribution might be reduced to about 5x because of hand tremor.
With the Porroprism binocular still having a 2x advantage over the roof prism binocular.
 
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With a 6 yard baseline and 28x magnification, the baseline is about 90 times an average IPD.
Here the objective spacing has more contribution than the magnification.
Of course these naval rangefinders have very large components from both the objective spacing and magnification.

Another interesting variant is the long distance rangefinder that uses the curvature of the earth as the means of distance measure.
The operating height of the instrument is known. The target ship is identified and the size and height above sea level is known, so it is fairly simple to work out the distance by how high above the horizon the control station of the target ship seems to be.

Using, say 8x binoculars, a Porroprism binocular with the wider objective spacing compared to a roof prism binocular will give twice as much stereo effect.
Of course this is significant.
But both bring things 8x closer and this magnification has more effect than the two times due to the wider Porroprism objective spacing.
Hand held the magnification contribution might be reduced to about 5x because of hand tremor.
With the Porroprism binocular still having a 2x advantage over the roof prism binocular.

Hi, Binastro:

“Height of the Eye” is, without a doubt, a very important concept for most of the world’s navies to understand. However, based on what you have just said, it would appear those navies have spent BILLIONS of dollars, pounds, marks, yen, etc. designing, building, repairing, and maintaining superfluous gear. Am I wrong?

A person with a hi res, 48-inch TV—sitting 6 feet from it—will have a much nicer view than his friend who pays $11.50 for a small bag of popcorn and a small soft drink and gets to sit near the back of a theater to watch the same movie. Yet, people are still doing it.

Wherein does the truth lie? Some say, “There’s no accounting for taste.” They all should. :cat:

Bill
 
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I would think that a coincident or stereo rangefinder is more accurate than the rangefinders using the earth's curvature.
The height above the horizon varies with the weather, anomalous refraction and mirages. But these horizon rangefinders were used.
Vertical heights are affected by mirages, but horizontal distances very little.

For gunnery the coincident or stereo rangefinder would be superior.
But I think Bismarck had radar controlled guns.

Nowadays laser rangefinders are far more accurate, as probably is modern radar.

As for T.V. at home compared to a cinema. The cinema is much more immersive and impressive.
I remember watching Top Gun, I think, in a cinema and the climbing F14 Tomcats were spectacular.
At home nothing seems to happen as the aircraft climb. Most disappointing on T.V.
I am not sure I ever went to an outdoor cinema as happens in the U.S.

I saw recently a Panasonic 77 inch T.V. advertised at about £10,000. I think a cinema visit is the better option.
 
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But I think Bismarck had radar controlled guns.

Yes, but YOURS were better!

I think, as an aside, it is nice to point out that Bismarck, Tirpitz, Yamato, and Musashi all learned—the hard way—that the days of conflicts between large, expensive battlewagons were over. Three of the four mentioned were sunk by airpower—after spending much of their lives in hiding—and although the Bismark was sunk after a barrage of projectiles and torpedoes it was slowed and made to go in circles because of a torpedo from a Swordfish ... biplane jammed the rudder! :cat:

Bill

PS Yes, Bismarck WAS scuttled. BUT, it wasn't going to make it to Brest, anyway. In his 1960 hit, Sink the Bismarck, Johnny Horton sang, "the FIRST shell hit the bismarck, they knew she couldn't last." Well, that's taking poetic license to the max! There were 2,700 projectiles, 8 inches or above, fired at the beast.
 
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