I still think the non-IS f4 is the sharpest of the siblings when peeping. No one in the world could tell the difference on most-sized prints or web-viewing though between them. As we all know, all 4 are tremendous lenses. Contrast reproduction "pops" equally well on all of them. But if we're peeping, the nod goes to the non-IS f4 IMHO. I'm a big fan of the relative size/weight though of the f4s.

I think both non-IS lenses take a TC slightly better than the IS siblings. I have the IS ones (and wouldn't give them up), but I've used and viewed countless crops at 100% of all the lenses with TCs and again the nod is to the non-IS. That said, the difference is slight and more academic than practically-relevant for most people.
I love IS.
I just posted this tonight http://www.pbase.com/lightrules/5telezooms![]()



