Re: Exact fl of lenses... 220 VR

[ADavidhazy <ANDPPH@xxxxxxxxxxxxxxxxxx>]

Gentlemen,

I probably got into this discussion a bit late but I can not imagine how the
focal length of a lens would be a variable. Focal length by definition is a
fixed factor (zooms excluded of course!).

The things that _are_ variable in a rotating panning camera are the center of
rotation used, the amount of film that is transported through the camera per
unit of time, the use of focus adjustments ... and maybe a couple of other 
ones but I can't think of them right now.

I could see how changing the rotation speed of the camera might lead to
differences in the amount of film transported through it per revolution but
this is, imo, a highly unlikely scenario in a precision camera system. 

Best regards,

Andrew  o o  0 0 o . o  Davidhazy, Imaging and Photo Tech
         \/\/\/\/\/\/          http://www.rit.edu/~andpph
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