dondidnod wrote:One optical problem with using wide angle lenses is that they distort when you have a subject close to the lens that becomes magnified. Wide angle lens distortion is everything to do with camera to subject distance and nothing to do with the lens being 'wide angle' or not having floating elements.
What both of you are referring to is the exaggeration of perspective by wide-angle lenses compared to our natural perception (which is an illusion created by the brain, since we have pretty much fisheye view horizontally). Just as telephoto lenses make the perspective seem flat.
Distortion is a deformation of the picture towards the edge areas, which can be barrel or pincushion shaped. Wide-angle lenses are more critical in this respect, with some even showing complex 'moustache' distortion, a combination of barrel and pincushion. While the simpler forms are pretty easily compensated by software these days, the latter would still be a problem. Floating elements might help with distortion too, but the main reason for these was close focus, as already mentioned.
BTW, AFAIK the Minolta MC 2.8/21 mm was the first lens with floating focusing, calculated by a 'supercomputer' of that age!