I’m working with a maya artist - they need to know how to set up 4 maya cameras, each one looking at a different wall of a room from a certain point in the room.

I can do this easily in v4 using perspective look at rect or other techniques, but there is no direct way to use the resulting VP matrix in Maya. Maya is expecting trad camera & lens parameters like focal length.

Yea maya quite nice using python scripts to get stuff u need inside. I use quite often script to get points from vvvv inside maya
For focal to fov I’m sure u can find on google however u can expect to have exactly fov to focal formula

if anyone knows Maya, I’m still interested in the best way to do this, and in particular if it’s possible to recreate something akin to lens shift (which would mean having different FOV for top/bottom/left/right

a tricky part (that I didnt know about even I am using for a long time maya) is that the camera aperture is being measured in inches. So it is just an implementation of a formula 2artan(x/(2f)), where x is the diagonal of the film and f is the Focal Length.
Here is a very common and easy to find place and start with : http://kmp.bdimitrov.de/technology/fov.html

You may check also the attached file f2FOV, it might help you.

I cant see why you have to mess with python in maya, you can avoid it and do all the math in vvvv. Then you may provide the numbers you want to the rest of your team :)