Peter, The optical formula and mechanics are different. I don't have the FA or F, but I believe both use internal focus mechanisms. Theses lenses don't change length as you focus. I am not sure if there is much difference in image quality. I'd be interested in any comparisons. Regards, Bob S.
On Sun, 14 Nov 2004 18:07:18 +0100, Peter Smekal <[EMAIL PROTECTED]> wrote: > Are there any differences between 100 mm f/2.8 F Macro and 100 mm f2.8 FA > Macro, let's say in optics or mechanics? > > Peter, Sweden >
