On Mon, 8 Dec 2003, Francis Alviar wrote: > How about an FA 50mm f/1.4 coupled with a 2x extender? Will it be > as sharp as say an FA 100mm f/2.8 macro?
Probably not. The teleconverters are generally designed to work a variety of lenses and need to make some compromises. The 50/1.4 plus teleconverter will almost definitely have more elements than the 100/2.8. Pentax teleconverters don't autofocus either. I can't find my 2X-S right now, but I remember it reporting funny f-stops to my *ist D (but that might have only been when using it with a Tamron Adaptall lens). alex