I have a question about a LF lens term. "angle of coverage" is defined in an old Calumet catalog as "the angle formed lines connecting the image nodal point to opposite sides of the image circle." This measurement is often prominently featu red is LF brochures and what not; so my question is: what is its significance? T he diameter of the image circle. focal length, aperture range, etc. seem far mor e important.

Thanks.