Quote Originally Posted by GSPhoto
The IS is amazing on the 2.8 which I would imagine same on f/4.

The IS on the f4 is in fact a bit better (3rd generation, 4-stop). The f2.8 has a 2nd generation, 3-stop IS. The f4 is considered a bit sharper too. Also keep in mind that the f4 is half the weight of the f2.8, so it's easier to carry around.


Tony