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  1. B

    Which roofs are better for their 3D view?

    Hi Ed. I haven't read your links but a surgeon using magnifying binocular glasses at close range is quite different to using a binocular at 30m, 40m or 100m. With say a 10x binocular I can see the stereo separation of several close planes at 100m. This is not monocular clues but actual stereo...
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    Which roofs are better for their 3D view?

    It depends on the distance of the objects one is looking at. If I am in the street with the pigeons around my feet and out to say 3 metres then viewing them is best with unaided eyes or with glasses. This gives the maximum depth of field, and stereo. Binoculars are not much use here. But...
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    Which roofs are better for their 3D view?

    An 8x roof prism binocular with IPD spacing of objectives amplifies the two separate images that differ by a small angle by 8x. At a distance, there may be no stereo image at all with the unaided eyes, but the binocular clearly shows a stereo image. And yes the 8x binocular makes things look...
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    Which roofs are better for their 3D view?

    Thanks Ed, I enjoyed reading that. b3rd. What does this have to do with optics. Not much, except that long held ideas may be wrong, and light rays can be bent by gravity I suppose.
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    Which roofs are better for their 3D view?

    What was a great surprise to me was to be informed recently by a world class satellite expert the following. The so called parabolic flights to simulate weightless conditions, in I think strengthened Boeing 727s, cannot be parabolas. They must be ellipses. Furthermore, and negating my teaching...
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    Which roofs are better for their 3D view?

    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...
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    Which roofs are better for their 3D view?

    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...
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    Which roofs are better for their 3D view?

    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...
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    Which roofs are better for their 3D view?

    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...
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    Which roofs are better for their 3D view?

    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...
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    Which roofs are better for their 3D view?

    If one looks at an object 2 feet (600mm) away with one eye in room lighting with a 4mm eye pupil, the angle difference between the left and right side of the pupil is 23 arcminutes (1 part in 150). This is a significant angle. It is the same angle as using two eyes 2.5 inches (63mm) apart at 31...
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    Which roofs are better for their 3D view?

    The photo stands out better with one eye, but not the other due to the need for new glasses. It is flatter using both eyes.
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    Which roofs are better for their 3D view?

    With one eyed stereo. I am looking at a tumbler of water on the table at 2ft and it has depth. I think this is the result of the image on the retina, in which the edge rays are at slightly different angles and the brain recognises this. It could also be a result of different depth focus, but I...
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    Which roofs are better for their 3D view?

    Thanks Ed, I will try to read your references. What bothers me about perception is highlighted by the excellent artist and seemingly intelligent guy who definitely saw a 20 mile wide spacecraft at night hovering in the sky to the north of Manchester and his numerous pals who see similar...
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    Which roofs are better for their 3D view?

    Hi Ed, Thanks. I haven't yet read the article but will comment on your post 24. I think you misunderstood me by highlighting the comments on using pupil size and telescope aperture. I am not talking of the perception of space, distance and size, which I think Gibson discusses. I am talking...
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    Which roofs are better for their 3D view?

    My two old computers could not access the pdfs referenced by Ed, but I was able to read an analysis of Gibson's ideas by E. Bruce Goldstein 1981. I can read some pdf files but not the referenced one. However, I consider Gibson's and Goldstein's work too complex regarding how far an image can be...
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    Which roofs are better for their 3D view?

    3D depends on magnification and distance and the observer's acuity. It has little to do with the distance between objectives, which varies little between binoculars, except reversed Porroprism binoculars. Even with these 3D is easily observed because of magnification, say 6x to 8x. Looking at a...
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