3D films

For the discussion of the sciences. Physics problems, chemistry equations, biology weirdness, it all goes here.

Moderators: gmalivuk, Moderators General, Prelates

Mayaz
Posts: 2
Joined: Tue Jan 26, 2010 12:57 pm UTC

3D films

Postby Mayaz » Tue Jan 26, 2010 1:08 pm UTC

Lately I've noticed that there are more and more films in the cinema that are in 3D. I hear from everyone that they are great, so about a month ago, I went to see one myself. When I put the glasses on and watched the screen however, the film did not become three dimensional! Apparently, because I have had an operation to my eyes when I was little, I can't see these films in 3D. The weird thing is that I went to Disneyland when I was 11 and there I could see the 3D film. Now I wonder what the difference is and why I can't see it anymore. If there will be 3D television in the future, I'm screwed!

Fume Troll
Posts: 254
Joined: Wed Jan 13, 2010 8:06 am UTC
Location: Scotland / Norway mainly

Re: 3D films

Postby Fume Troll » Tue Jan 26, 2010 1:43 pm UTC

Can you see the real world in 3D?

mr-mitch
Posts: 477
Joined: Sun Jul 05, 2009 6:56 pm UTC

Re: 3D films

Postby mr-mitch » Tue Jan 26, 2010 2:00 pm UTC

What did the '3D' film look like? (Was it fuzzy, or something else?) Also, some 3D films are very bad and hardly anything is 3D.

User avatar
Tass
Posts: 1909
Joined: Tue Nov 11, 2008 2:21 pm UTC
Location: Niels Bohr Institute, Copenhagen.

Re: 3D films

Postby Tass » Tue Jan 26, 2010 2:07 pm UTC

Mayaz wrote:Lately I've noticed that there are more and more films in the cinema that are in 3D. I hear from everyone that they are great, so about a month ago, I went to see one myself. When I put the glasses on and watched the screen however, the film did not become three dimensional! Apparently, because I have had an operation to my eyes when I was little, I can't see these films in 3D. The weird thing is that I went to Disneyland when I was 11 and there I could see the 3D film. Now I wonder what the difference is and why I can't see it anymore. If there will be 3D television in the future, I'm screwed!


Can you see on both eyes? If you place an object right in front of you (a meter or so), close one eye and position your head so that the object aligns with something in the background, if you then open the other eye and close the first without moving your head, can you se it has moved relative to the background? If you open both eyes, which of the images do you see? Or do you see two versions of the object simultaneously. Do you see the 3D in real life?
Last edited by Tass on Wed Jan 27, 2010 11:00 am UTC, edited 1 time in total.

Mayaz
Posts: 2
Joined: Tue Jan 26, 2010 12:57 pm UTC

Re: 3D films

Postby Mayaz » Tue Jan 26, 2010 9:22 pm UTC

The doctors told me that I don't see the real world in 3D. But I had the operation when I was 3,5 so I have no idea what the world should look like. I don't know the difference.
I saw the film as a normal film, it was not fuzzy or anything, but there was nothing different from usual.

User avatar
SimpleSimon
Posts: 16
Joined: Mon Jan 25, 2010 10:56 pm UTC

Re: 3D films

Postby SimpleSimon » Tue Jan 26, 2010 10:01 pm UTC

Hmmm, i would say it sounds like you're blind in one eye but i'm pretty sure you would know.

Funnily enough I wrote a blog entry on 3-D films, might help explain why you can't see in 3-D
Check out my Blog

http://simplesciman.wordpress.com/

Its not shit, promise

Carnildo
Posts: 2023
Joined: Fri Jul 18, 2008 8:43 am UTC

Re: 3D films

Postby Carnildo » Wed Jan 27, 2010 4:38 am UTC

The human vision system has many different ways of determining "three dimensions" (obligatory Wikipedia article), most of which work with just one eye. The current generation of 3D movies only use a few of those, such as the stereopsis and parallax methods. At the same time, those movies actively confound other methods, such as the accomodation and convergence -- since the movie screen is at a fixed distance from you, you can't adjust your eyes to explicitly "focus" on near or far objects, and trying to do so will give you a headache.

User avatar
Tass
Posts: 1909
Joined: Tue Nov 11, 2008 2:21 pm UTC
Location: Niels Bohr Institute, Copenhagen.

Re: 3D films

Postby Tass » Wed Jan 27, 2010 6:48 am UTC

Carnildo wrote:The human vision system has many different ways of determining "three dimensions" (obligatory Wikipedia article), most of which work with just one eye. The current generation of 3D movies only use a few of those, such as the stereopsis and parallax methods. At the same time, those movies actively confound other methods, such as the accomodation and convergence -- since the movie screen is at a fixed distance from you, you can't adjust your eyes to explicitly "focus" on near or far objects, and trying to do so will give you a headache.


Eh, convergence would go under stereopsis or parallax, since the eyes see two different pictures but think they are the same. It is only the accommodation that is wrong.

User avatar
jaap
Posts: 2094
Joined: Fri Jul 06, 2007 7:06 am UTC
Contact:

Re: 3D films

Postby jaap » Wed Jan 27, 2010 8:12 am UTC

Tass wrote:
Carnildo wrote:The human vision system has many different ways of determining "three dimensions" (obligatory Wikipedia article), most of which work with just one eye. The current generation of 3D movies only use a few of those, such as the stereopsis and parallax methods. At the same time, those movies actively confound other methods, such as the accomodation and convergence -- since the movie screen is at a fixed distance from you, you can't adjust your eyes to explicitly "focus" on near or far objects, and trying to do so will give you a headache.

Eh, convergence would go under stereopsis or parallax, since the eyes see two different pictures but think they are the same. It is only the accommodation that is wrong.


As far as I understand it, stereopsis/parallax has to do with the difference in the images, whereas convergence has to do with how cross-eyed your eyes have to be to look at an object. These are of course related, but in a 3d film screening the parallax does not depend on how far away from the screen you are, while the difference in convergence between supposed near and far objects does depend on seating. If you are the correct distance from the screen so that the images are the intended size, then convergence is correct and only the accommodation (focussing) is wrong.
In another avatar thread it was reported that they have blurred objects very close to camera. This seems like a bad move to me, as some people get a headache trying to focus on them and failing.

Carnildo
Posts: 2023
Joined: Fri Jul 18, 2008 8:43 am UTC

Re: 3D films

Postby Carnildo » Thu Jan 28, 2010 3:50 am UTC

jaap wrote:
Tass wrote:
Carnildo wrote:The human vision system has many different ways of determining "three dimensions" (obligatory Wikipedia article), most of which work with just one eye. The current generation of 3D movies only use a few of those, such as the stereopsis and parallax methods. At the same time, those movies actively confound other methods, such as the accomodation and convergence -- since the movie screen is at a fixed distance from you, you can't adjust your eyes to explicitly "focus" on near or far objects, and trying to do so will give you a headache.

Eh, convergence would go under stereopsis or parallax, since the eyes see two different pictures but think they are the same. It is only the accommodation that is wrong.


As far as I understand it, stereopsis/parallax has to do with the difference in the images, whereas convergence has to do with how cross-eyed your eyes have to be to look at an object.

Yes, convergence information comes from your eye muscles, and is a measure of how cross-eyed you need to be to center an object in each eye's field of view. Stereopsis information is based on the difference in how each eye sees a scene, and works with static pictures. Parallax is based on how the scene changes with head/camera motion.

In another avatar thread it was reported that they have blurred objects very close to camera. This seems like a bad move to me, as some people get a headache trying to focus on them and failing.

That's the biggest problem with 3D films right now: depth-of-field techniques to highlight the important parts of a scene work in 2D, but fail badly in 3D. You absolutely must put the entire scene in sharp focus if you're working in 3D -- if you're using anything but small-aperture lenses, you're doing it wrong.

User avatar
Krikkit_Robot
Posts: 74
Joined: Mon Aug 17, 2009 3:43 am UTC
Contact:

Re: 3D films

Postby Krikkit_Robot » Thu Jan 28, 2010 4:46 am UTC

I have a lazy left eye which will sometimes even shut itself off. If I cover my right eye and read I can go along fine but sometimes things will get blurry and snowy like a TV with no signal and then it will just turn off and all I can see is the inside of my right eyelid. It is real strange, and it is even doing it right now.

I have never been able to see 3D images that required the red and blue filter glasses but the circular polarization films and images have always rendered great 3D images.
Image


Return to “Science”

Who is online

Users browsing this forum: No registered users and 9 guests