Optimisation from camera stations

[patcarbon]

Is there any point in optimising from camera stations alone?  From experimentations with UAV imagery I get the impression that yes but I'm not sure about the maths.  How can the X0Y0Z0 position of cameras model radial distorsion (and others) of a tie point?  What exactly does PS do when you hit the optimise button with only camera stations?

Confused.

[bigben]

camera stations are effectively a single camera, made up of multiple cameras. Lens distortion parameters are optimised based on tie points between camera stations, or based on overlapping regions of images if there is only one camera station. (Great way to calibrate a fisheye lens by the way).  As for camera position, each camera will have the same position within the group, but the position of each station will be optimised.  If images shot from the same position aren't grouped as a station it's possible that the distances between their positions may increase depending on the detail I the images and spread of tie points. Defining a camera station simply adds an additional known piece of information into the optimisation process and IMO should be done whenever possible.