Film-Tech Forum ARCHIVE: Picture width of "Edge of Tomorrow"

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Posted by Peter Castle (Member # 1997) on 07-16-2014, 12:10 AM:

We recently showed "Edge of Tomorrow" in 3D and were very concerned that our lens zoom was not working as the picture did not reach our side masking. It turned out that, while trailers did reach, the feature did not. Anyone know why this particular feature did not use all 2048 horizontal pixels?

Posted by Carsten Kurz (Member # 5396) on 07-16-2014, 05:35 AM:

http://3droundabout.com/2011/11/5430/the-basics-of-shooting-stereoscopic-3d-part-3-edge-violations-and-floating-windows.html

'Floating window

Another major issue with screen edges is when an object placed in front of the screen plane (i.e. it has negative parallax) and exits the screen in one eye’s image before the other. In this instance, the illusion of 3D is broken, since without both the left and right eye containing the same portion of the image, there can be no 3D effect.

This image has a person breaking frame to the right side of the image - the chap in the black t-shirt. Close each eye in turn while looking through a set of anaglyph glasses to see the differences. (Image courtesy of Pietro Carlomagno www.carlomagno3d.it taken from the set of Inferno)
The only real way to overcome this issue is to either change the convergence point, such that all objects are behind the screen window (i.e. have positive parallax), or to manage it in post by ‘zooming’ into the centre of the image in order to remove the problem object at the screen boundary from both the left and right eyes.

However, a more dynamic way to deal with the problem is to dynamically crop just the eye that has more of the object such that it matches the other eye.

This image has a floating window used to crop the extra information within the right eye images such that the information contained within each is identical. You have to work with us on this as it is very hard to see the benefit of this in static images. (Image courtesy of Pietro Carlomagno www.carlomagno3d.it taken from the set of Inferno)
This approach has become known as ‘floating windows’, or more accurately ‘floating crops’, as the edges of the left and right eyes are cropped dynamically depending on the objects at the edge of screen.

Note that although the chap in centre frame is well in from of the screen plane there is no issue as the top and bottom crop points are identical. If the camera were panning vertically however, there would be an issue as the crop points would no longer be identical.'

- Carsten

Posted by Peter Castle (Member # 1997) on 07-16-2014, 06:35 AM:

I am aware of the floating window, but this movie had no content in these areas on both sides of the picture - more missing on the right than the left.

Posted by Carsten Kurz (Member # 5396) on 07-18-2014, 05:51 AM:

You decide for floating windows for the whole feature. You can not switch in between if there is no negative parallax content in certain shots.

Usually you will find a framing chart with the DCP that also explains this.

- Carsten