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Keep doing that and you'll go blind

abc.net.au

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Re: Keep doing that and you'll go blind

#11

Post by sdfx »

barrkel wrote: post #10
sdfx wrote: post #4

From the article: The Wikipedia entry on depth perception (an excellent read) lists ten different cues that your brain uses to figure out exactly how far away something is. Parallax is just one of them. Since the various movie and television display technologies only offer parallax-based depth cues, your brain basically has to ignore several other cues while you're immersed in the world of Avatar. This is why the 3D…

From the Wikipedia article, of the 13 depth cues, only 2 aren't properly present in 3D films - accommodation (having to focus the eyes) and peripheral vision - and the peripheral vision cue is also missing from regular cinema, TV etc. So are there more things going on here? It seems unlikely to me that the focus of the eye lens is having a big impact.

I don't know about the accommodation, but isn't the loss of peripheral vision like looking out of a window? Think of the movie screen as a big window into the world.

Not on the list (I think) but what about head movement of the viewer? If I move my head slightly to one side the picture stays the same while I expect to look behind an object.

Re: Keep doing that and you'll go blind

#12

Post by daveungerer »

tocomment wrote: post #5

Doesn't normal 2D TV also force you to ignore even more depth perception cues? We still have relative size, parralax, etc telling us that the things on the screen are at different depths.

Did we read the same article? 2D TV doesn't trick the brain into thinking it's 3D. Your brain can clearly see it's 2D. When you view fake 3D, the brain thinks it's 3D. But now that your brain is in 3D mode, it has to turn off processing for a lot of cues it would normally take into account, due to the fake 3D not being a complete simulation of reality.

Re: Keep doing that and you'll go blind

#13

Post by iujhygfbh »

JunkDNA wrote: post #7

I really wish there was a way to do 3D that allowed your eyes and brain to naturally do what they do in the real world, though perhaps we're a long way from that? Anyone familiar with or doing any research on better mechanisms for 3D? I have yet to experience any sort of 3D entertainment that isn't (at least initially) disorienting. The need to wear glasses constantly ruins the experience. But even beyond that, the u…

In the real world - you don't really see 3D very much.

Your eyes are only 0.1m apart so anything more than 3-4m away isn't really in 3d anyway. Everything in the distance is handled by your knowledge of it's relative size and position - which works just as well on a 2d screen anyway.

Try it, cover one eye and look at the scene, you will see a difference on your desk, but no difference for the scene outside your window.

That's why most 3d movies have lots of things flying at you and other gimmicks - it's because otherwise there wouldn't be much 3d-ness

Re: Keep doing that and you'll go blind

#14

Post by gjm11 »

This seems like sheer alarmism.

Made-up pseudomedical terminology? Check.

Won't-somebody-please-think-of-the-children plea? Check.

Confident claims of what's likely to happen, right alongside complaints that no one has done any research? Check.

(I originally had a paragraph here about how he links to the Wikipedia article on depth perception and says: here are all the distance cues your brain uses; 3-d movies only provide one of them; oh noes, your brain will get all confused -- whereas in fact almost all the distance cues listed there are available in 3-d movies, and indeed almost all of them are available in plain ol' 2-d movies. But someone else already did that in more detail, so I shan't bother.)

Incidentally, I see that Mark Pesce's own Wikipedia page describes him inter alia as a "hack and shameless self-promoter". I'm about to delete that since it's obviously unencyclopedic and non-NPOV, but this article sure makes it look like it might be true.

Re: Keep doing that and you'll go blind

#15

Post by aarongough »

JeffJenkins wrote: post #8

I have Amblyopia -- an eye condition where the image from one eye is partially suppressed by the brain. I'd been wondering what a 3D movie would do to me for a while since parallax doesn't work when you brain is processing the images from each eye as separate. It turns out that the answer is not much of anything, but I still have to wear the glasses to filter out the second image. Although I'm sure it will be nice fo…

Similar situation here. I was born with one eye only having about 10% of the nerves that it was supposed to, and the ones I have are only connected to the peripheral areas of the retina.

I've never been excited about 3D movies or games because they simply do not work for me, which was always a source of disappointment when I was a kid.

Personally I really can't see it catching on... Who wants to have to wear special glasses while sitting in their house watching TV?

Re: Keep doing that and you'll go blind

#16

Post by gjm11 »

tocomment wrote: post #6

I wish we could just move to holograms. What's holding us back exactly? I could never find a straight answer.

Updating them in real time is difficult. You need a feature size comparable to the wavelength of the light being used, which would mean somewhat less than 1um. The smallest pixel sizes in LCDs these days are on the order of 5um across or so. Other kinds of imagers (DLP, for instance) are comparable or worse.

Re: Keep doing that and you'll go blind

#17

Post by rationalbeaver »

JunkDNA wrote: post #7

I really wish there was a way to do 3D that allowed your eyes and brain to naturally do what they do in the real world, though perhaps we're a long way from that? Anyone familiar with or doing any research on better mechanisms for 3D? I have yet to experience any sort of 3D entertainment that isn't (at least initially) disorienting. The need to wear glasses constantly ruins the experience. But even beyond that, the u…

To your point about camera focus: I believe that this was addressed in Avatar by rendering the whole scene in focus (which makes it look cartoony if you aren't viewing in 3D).

To your main point: The 3D still didn't feel completely natural. I did not feel like the camera was forcing me to focus on anything in particular, but I did feel like the whole thing was slightly blurry. Maybe it was my position in the theater (off to the right side of a huge Imax screen, rather than dead center), but it detracted from the experience because I wanted to appreciate the details and they were often fuzzy due to imperfect alignment of the images.

Re: Keep doing that and you'll go blind

#18

Post by bartl »

tocomment wrote: post #5

Doesn't normal 2D TV also force you to ignore even more depth perception cues? We still have relative size, parralax, etc telling us that the things on the screen are at different depths.

I think you must be referring to perspective... which gives indeed an idea of 3D. Medieval paintings lacked perspective. But technically it's still 2D: both eyes see the same thing.

We are used to 2D: if you look around with one eye, or at very long distances: the moon, the sun and the stars are in 2D.

And we're used to 2D in drawings, paintings and photographs.

3D tries to trick you into seeing 3D by showing a different picture for each eye, but the illusion is far from perfect: according to this article we receive clues that point in different directions. And that, it claims, isn't healthy in the long run.

Re: Keep doing that and you'll go blind

#19

Post by tocomment »

gjm11 wrote: post #16
tocomment wrote: post #6

I wish we could just move to holograms. What's holding us back exactly? I could never find a straight answer.

Updating them in real time is difficult. You need a feature size comparable to the wavelength of the light being used, which would mean somewhat less than 1um. The smallest pixel sizes in LCDs these days are on the order of 5um across or so. Other kinds of imagers (DLP, for instance) are comparable or worse.

I don't understand. Can't we just have holograms with lower resolution?

Re: Keep doing that and you'll go blind

#20

Post by tocomment »

daveungerer wrote: post #12
tocomment wrote: post #5

Doesn't normal 2D TV also force you to ignore even more depth perception cues? We still have relative size, parralax, etc telling us that the things on the screen are at different depths.

Did we read the same article? 2D TV doesn't trick the brain into thinking it's 3D. Your brain can clearly see it's 2D. When you view fake 3D, the brain thinks it's 3D. But now that your brain is in 3D mode, it has to turn off processing for a lot of cues it would normally take into account, due to the fake 3D not being a complete simulation of reality.

The article says there are 10 depth perception cues. ONE of them is showing different images to each eye. 2D images do have some of the 10 cues. What is special about this ONE cue and not the ones that a 2D image has?

I.e., why does your brain turn off processing for the differing images to each eye cue but not for the parralax cue, etc?

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