It's all about that 2.8.I was shooting at a rest stop on the Interstate with him the other day, shooting semis, and I was getting clear shots (no motion blur) at an incredible 1/13th of a second hand held (!

You absolutely can't cut out motion-blur with a f/4.0 even with decent indoor lighting

Note that IS does not have any impact at all on subject motion blur, only on camera shake on your end.

- I was going to need to be wide open to shoot at an ISO that I trust on the 50D for weddings (no higher than 200 in my experience) and have a shutter speed that wouldn't give me motion blur during the proceedings.

And these shutter speeds let you freeze action - good if you want to capture a toast in lower light at a wedding or something (unless a bit of motion blur is desired, which can easily be obtained

That others had suffered the same problems as I, with older bodies

but that's fine as I either shoot wide open or stopped down to

And that is all the positives I am going to report on

Spend the extra $80-100 (or more) and get a nice B+W UV filter

Sure, it can't do portraits as well as the 24-70 f2.8 L II, but for almost all other situations, since I shoot between f4 and f5.6 most of the time, the IS system and the size advantage will more than make up for the lack of f2.8

f/2.8 L fantastic colors, sharp for a zoom, very versatile ego boosting and attention getting and heavy

The build quality is what you would expect from an L lens and this is a great first L lens for anyone looking to expand their collection and adding something of quality

I tried the EF 24-105 L to better effect, but not so much better to justify the price, or added

Color is comparable to a good L prime.

It's true it's not the sharpest L lens, but it's still an L lens and a lot sharper and stronger than a lot of non-L lenses in the standard zoom "walk around lens" category.

f/3.5-5.6 Rebel XTi Kit lens Muddy, slow, pile of junkCanon EF 17-40mm f/4 L Fantastic colors, sharp zoomed 17 to 24mm, ultra smooth zoom action, light weightCanon EF 24-70mm f/2.8 L Fantastic colors and contrast, sharp zoomed 40 to 70mm, zoom a little stiff at first, heavy, repair prone

The 24-70 L is sharp in the center at f/2.8 at all focal lengths

I would not say this lens is "Sharp", especially not as sharp as previous L glass I have owned

Obviously it is not as versatile as the 24-70 and there are some additional optical characteristics that make L series glass a bit better than non-L series glass, but the 85 F1.8 could be used for a professional portrait shoot without any concern at all.

And for an L Series, not too pricey or large either.

The 24-70mm L copy I had was comparably softer than my sharp-as-knife 70-200mm L in all aperture ranges.

not to mention that at f5.6 this lens is just as sharp as the f2.8 L II!If you want to compare to the 24-105 f4 L IS, it's a slaughter