I'm finally in the market for the "white lens". Just not sure if I should spend the extra cash on the 2.8 vs. the 4.0 .... <BR>When would the lower f stop come in handy for me? I mostly shoot during the day --

With the price incress in Canon glass you will be looking at about a $750.00 price difference (new) between the 2.8 and the 4.0 IS. I am very happy with my 4.0, but I shoot with it mostly in good light, and it's a LOT lighter.

I love my F/4.0L IS. The extra stop would come in handy with low light situations and indoors, however I've been pleasantly surprised at how well my F/4 does in low light. And when I'm indoors, I'm usually shooting people up close, and I use a different lens for that anyway. The IS is a must in my opinion...

yes I'm definitely going with the IS

The IS is at least one stop better on the f4 and if you're capturing motion where the IS isn't an advantage it's one level of ISO difference. <BR> <BR>The bokeh is better on the f2.8. <BR> <BR>"If you're not sure why you need f2.8 you probably don't" <BR> <BR>The f2.8 was designed for shooting low light sports, indoors or poorly lit stadiums. It's also a very popular portrait lens. If you're not into those why spend the extra $. <BR> <BR>One of the major test sites, photozone I believe, has called the 70-200 f4 L IS the best zoom lens ever from an IQ standpoint regardless of mfg, it's that good.

sweet! thanks Rich!