How do the two main 3d files types manage to display a full screen image?

[VideoKhahh]

Hello. Im still a newbie. This is only my second post. I have a basic question that I cant seem to find an answer to anywhere.

3d movies come in a few basic flavors. Over and under(top and bottom) and side by side. Both versions effectively display a full screen image by magically combining the half images in the file, filling the full screen.

How?

Taking side by side as an example. The movie file has two half resolution images placed along side one another. The left side is 960x1080 and the right side is 960x 1080. When the movie file is played on the proper 3d device, with the proper glasses the two half images merge into a screen filling full screen movie.

How

Its wayyyy more confusing when you consider top and bottom. In this 3d movie format, one image is placed on top of the other which when played on the proper 3d device merges into a full screen 3d image.

What is happening, so that when looking at the screen I dont see or even notice that the original picture had two images placed alongside one another or one image was on top of the other. How can two separate images combine so seamlessly that not only do they not give away that they were separate, but its only when you see the original file played to a non 3d tv that you realize that two individual images created the full screen image.

Why, when we take into consideration, top and bottom, do the two images fill the entire screen, somehow merging vertically while the eyes of the viewer are placed horizontally. Why dont I have to tilt my head to the side to see the correct picture?

I think you see my point. It doesnt even make sense that someone would think to invent such a technology. To do 3d,"This is what we will do, we will make a movie picture file of two slightly different images, stack them and when we play the file it will appear that everything is normal, and the movie will look normal.

Thanks in advance.

[newpball]

I think you see my point.

Not really!

The images are superimposed in such a way that the left glass picks up the left image and the right glass picks up the right image.

Various techniques accomplish this, from simple color coding to polarization all the way to active shutter systems.

[VideoKhahh]

Im not sure that you understand my dilemma. If I look out at the world with my 3d glasses on, the world looks fine. When I look at a movie authored top and bottom through the 3d glasses the top and bottom images merge into a complete picture "FILLING THE ENTIRE SCREEN" .

If I understand you correctly, that would only answer how the images combine to create one image. It doesnt answer how two slightly different half images combine to fill the entire screen. Again, if I understand you correctly, I would expect that the two combined images through the techniques you stated would create 1 image at either the top half or the bottom half of the screen.

Not one image filling the entire screen. To do this it would seem to require two images - one of the top of the screen the other of the bottom of the screen. Polarization or other technique combining the separate images to fill the entire screen. This is not what is going on. We have two identical half (for all intents and purposes) images, somehow combining to create a full screen image? How. Where does the height increase come from?

How do the glasses generate the height from two half height images. Still not understood.

thanks but I still have questions.

[newpball]

Im not sure that you understand my dilemma.

Your dilemma? What dilemma are you talking about?

You do not understand something. There is no shame in that. But it's not a dilemma, it's a misunderstanding that is in your head.

Google for 3D video and read some articles. For instance this one:

http://mashable.com/2011/02/07/how-does-3d-work/

[VideoKhahh]

Hello again. I read the referenced page and the question still holds. This is the dilemma that I was referring to. Of all of the pages I have read instructing how 3d works not one page answers my question, and I have been reading about 3d since its inception. That to me is what a dilemma is about. Nowhere am I getting the answer that fits.

I am asking how the rubiks cube is made not how to solve the puzzle. The cube has many moveable parts than somehow all stay together. How can such an object be made( actually I know the answer to this)? This is an illustration of what i am asking.

Let me try again.
In a top and bottom 3d video there are two images stacked. Both are 1920x540 in size. There is one image at the top of the screen 1920x540 in size and there is the other image 1920x540 in size at the bottom. I the viewer, with out my magical 3d glasses see the two individual images, the top stacked on the bottom image.

Lets say that the image is of a building that goes from top to bottom, no extra space. The bottom image has a building that that extends from zero to 540. The top image has an image that extends from 541 to 1080

When I put on my 3d glasses the 1920x540 image at the top and the 1920x540 image at the bottom somehow become one 1920x1080 image full screen.

Where does the merging and full screen come from? Where does the magnification of the two separate images and merging come from. It doesnt seem to come from the glasses but thats the only thing that is different from the original viewpoint. If I put the glasses on and look at the world it isnt magnified, yet somehow two buildings 540 pixels in size has become one building 1080 pixels in size from two half size buildings.

If I set a picture of the eiffel tower as wallpaper on a monitor and then take the same picture and set it as wallpaper on a monitor twice the size the wallpaper is half the size of the screen. Yet in the 3d world if I take two pictures of the eiffel tower and set them as wallpaper I get one building twice the size of the original picture. How does this happen?

Oh boy, I knew this would be hard to describe. But please let me know your thoughts. Its still a puzzle to me.

[Cornucopia]

see other thread...

Scott