My experience with the f/4 is that optical quality is fantastic. I don't think you are going to see enormous increases in optical quality in the 2.8IS. However, you don't get 2.8 (which AF would like) and you don't get IS, so you need to weight that up.
The f/4 is a very nicely weighted lense, just enough heft, but not heavy. Cheers David * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
