Subject: RE: Long zoom recommendations
distortion is a term used in optics nearly always if not always associated with geometry and it doesn't improve with stopping down.
Technically correct.
Distortion:
"An optical aberration caused because the transverse magnification may be a function of the off-axis image distance. May be positive (pincushion distortion), or negative (barrel distortion)."
(reference quoted from: http://scienceworld.wolfram.com/physics/OpticalAberrations.html),
is a subclass of optical aberations.
The sad fact is that distortions are aberations, but aberations are not necessarily distortions.......
Technically, anyway.
William Robb
