Bryan Heit <bjh### [at] nospamucalgaryca> wrote:
> (povray assumes square pixels and will render a 720x480 at 
> an aspect ratio of 3:2, not 4:3).

  This is simply incorrect.

  POV-Ray doesn't make any assumption on pixel aspect ratio whatsoever.
The only assumption it makes is the whole-image aspect ratio, which by
default is 4:3, but changeable with the 'right' keyword.

  This means that if you render an image (without specifying any 'right'
in the camera) with an aspect ratio other than 4:3, the contents of the
image will not change (IOW the portion of the scene which the viewing area
covers will remain the same). In other words, the result will be "squeezed"
if viewed with square pixels.

  If you want to render an image with an aspect ratio of 4:3 (regardless
of the shape of the pixels in the target media) then you don't have to
do anything to the scene. You just render it with the resolution of the
target media (eg. in this case DVD). If the target media stretches the
image so that it will cover a 4:3 area (IOW uses non-square pixels), then
the image will be correct.

  Only if you want to change the aspect ratio of the image without
changing the aspect ratio of the pixels, then you have to use the
'right' keyword for that.

-- 
                                                          - Warp

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