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When you go to scenic areas there are often information signs that explain what you are looking at. This is usually an illustration of the view with arrows and names pointing to various landmarks.
These information signs are sometimes hard to understand because: a) it is difficult to represent perspective
("is the arrow pointing to that close hill or that mountain in the distance?"); b) you can't look at both the view and the sign at once; c) the illustration is usually a narrower field of view than the view itself.
I think this information could be presented in a more interesting manner (especially for kids). My idea is a transparent cylinder at head height that is about 30cm in width and a few metres in diameter. The cyclinder would have information markings such that when you stand in the centre of the cylinder the markings align with the landmarks. The markings could be made 'blurry' so as to appear in focus when you look far in the distance.
There could even be a rotating platform with headrest at the centre of the cylinder to ensure the viewer's head was in the correct position.
similar idea to show what ruins looked like
https://i.redd.it/8vu1qrr3l7nz.jpg
located at the Heidentor building in Petronell-Carnuntum, Austria [xaviergisz, Nov 11 2021]
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I like the idea, so [+]. However, there is a technical error: |
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// The markings could be made 'blurry' so as to appear in
focus when you look far in the distance.// |
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Sadly not. If they're blurry close up, they'll just be blurrier
when you look into the distance. Unless you do something
clever with lenses. |
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Ah, OK. Maybe the markings are printed 'double-vision' style on the transparent cylinder but appear in focus as you look into the distance; would that work?. |
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Not quite sure what you mean, but I think not. You'd have
to put a correcting lens in front of each label, but that
woudn't be so difficult. |
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You could do it with a polarized 3D transparency and 3D
glasses. Then the arrows would appear in depth giving the
illusion that they were actually over the object they
indicate. Hey, that's actually a brilliant way of implementing
this. Consider adding it to your idea. |
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You'd still have a focus problem: each of the independent
images on the cylinder will be out of focus when you look
"through" them into the distance (though you will solve the
parallax-depth problem). |
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What you would see, in effect, would be a label which
appears to be distant but blurred. |
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/The markings could be made 'blurry'/ |
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If you did not make them blurry on purpose, they would definitely become so after a few grade schoolers occupy the transparent cyclinder. |
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not true MB, when you integrate deep field 3D you are changing the angle at which your eyes focus and thus an appropriate "depth" 3D image would look fine if presented in front of a distant object. I could draw a picture but I think you get the idea. 3D staging and actual depth staging are the same process. |
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yes. We "uncross" our eyes to look (stage) a "far away" 3d object. Our eyes are then as "uncrossed" as they would be for a "real" distant object. |
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not sure i follow you on that. Isn't the focal length of the lens tuned to the distance to the back of the eye not the distance to the focal depth? Could you explain? |
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//not true MB, when you integrate deep field 3D you are
changing the angle at which your eyes focus and thus an
appropriate "depth" 3D image would look fine if presented
in front of a distant object. I could draw a picture but I
think you get the idea. 3D staging and actual depth staging
are the same process.// |
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I think this is wrong. There are two things involved: focal
distance of the eyes, and convergence angle*. The 3D
images will solve the convergance problem, but not the
focal length. If you're looking at a distant scene, your eyes
will be focussed on infinity, and anything closer will appear
out of focus. |
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Look at it this way: what would a one-eyed person see
with this system, if they were wearing one of the two 3D
lenses? They would focus on the distance, and see a single
image on the cylinder. But that single image would be
blurred. It really, truly would. |
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And the brain cannot contruct a sharp image from two
blurred images, even if they are correctly superimposed
(as they would be). It really, truly cannot. |
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(And, as an aside in response to some earlier annos, the
convergence angle and the focal length are >usually<
synched with eachother, so that when you look further
away your eyes both diverge and extend their focal length;
but this is a matter of habituation and is easily overcome.
I often view side-by-side stereograms without stereo
glasses; you just have to learn to focus on the page whilst
diverging or crossing [depending on the type of
stereogram] your eyes to the necessary extent.) |
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I have often wondered.... if something is "in focus" can a small adjustment be made to bring it into "extra focus"? |
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"Extra focus" being.....? |
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"In focus" means that light rays from a single point on the
image are brought to a single point on the retina. You can't
get much more in focus than that. |
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If the cylinder had sufficient radius - probably about 20 metres - so as to reduce the parallax effects, then it would probably work without additional optics. |
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//Maybe the markings are printed 'double-vision' style// |
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This could work. It would be the same technique those old "I See It" pictures used. |
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You would just need to make two images side by side at a distance equal to the distance between the two lines of sight of the two eyeballs, respectively, as they would while converging on the object of signifigance. |
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Of course, the distance between the eyes is different from person to person, but it would be close enough, methinks. |
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I was thinking along the same lines as MikeD; using the 'magic eye' random dots type technology. And I think it would be easier to get than 'magic eye' because your eyes would already be focused at the right distance. |
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I know MB believes that a blurry image (or a seemingly random arrangement of dots) cannot appear as an in-focus image at a different focal length, but I'm not convinced. I'll see if I can find something. |
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MB does not "not believe" an image close up can appear in
focus when you're focussed on something far away. It is
just a sad fact, rather than a question of belief. |
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It *can* appear to be far away (using the various 3D tricks
to give the correct divergence between monocular
images), but it can't appear in focus *while you are
focussing on a real distant object*, unless you have
correcting lenses (which would then screw up the distant
image). |
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However, as [1.1428] points out, if the cylinder is big
enough, then images printed on it will effectively be "at
infinity" as far as your eyes are concerned, and there's no
problem. |
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Better yet, would it not be simpler to just place very large
labels on the distant features themseves? This would have
the advantage of being visible from many different
viewpoints. |
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//MB does not "not believe" an image close up can appear in focus when you're focussed on something far away. It is just a sad fact, rather than a question of belief.// |
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what about a transparent hologram? |
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Interesting question, to which the answer I do not know. |
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Psst... [MaxwellBuchanan],
I may have noted this elsewhere, and correct me if I'm wrong, but I think he's [0.875] not [1.1428...] - an 8th of 7, not a 7th of 8 (yes, I'm a maths geek...). |
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I think his (err, their) name is a parody of the character "7 of 9" in Star Trek: Voyager. So I think MB has it kind of right - the eighth person out of 7 (kind of like the twelfth man in cricket). But I don't know if [8th of 7] likes to be fractionalised. |
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I guess those steel pipes mounted like telescopes just aren't good enough any more. |
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Wouldn't a lot of this augmented reality interfere with the scenic-ness of the view? |
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Apparently this is called a "holographic combiner" used in head-up-displays, but I can't find much information about it. |
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