Camera and image size question

[voltron7]

Let's say I have a camera setup to render at 1000x1000 pixels.
Now, my client wants to "make the image twice as wide on the left side, without changing the camera."
Seems simple enough but I've never had the question yet.
I was thinking there would be an easy way using the frame buffer to change size to 2000x1000 but it does not work, so far.
Any tips would be great, thanks!

[flino2004]

make it 3000x1000 to be equal on both sides and crop it in PS or render region

[pokoy]

Martin Breidt's Overscan script does that:
http://scripts.breidt.net/index.html#overscan

[dean_dmoo]

http://www.peterguthrie.net/blog/2013/01/overscan

[voltron7]

Thanks a lot for the answers!