Controlling imaging properties of camera

[constant]

I am trying to find out how to get Vizard to display a scene as viewed by a specific camera. I construct a scene and then need to specify properties of the camera.

Say, I want to compare the image of a regular 35mm camera with a
- 18mm wide angle lens imaging on a 24x36mm^2 area
and compare the image to that of a view camera with
- 600mm lens imaging on 180x240mm^2 area.
Clearly, just changing the field of view using viz.fov will not be sufficient.

How can I control the imaging process to mimic the respective camera?