From the LensRentals Blog:
Author: Roger CicalaSee the entire post on the LensRentals Blog. For more information on the lens, see Bryan's full review.I like to start articles by stating my expectations, because, like everyone, my expectations going in color my opinion after seeing the results. Given Canon’s recent series of home-run lens upgrades, I expected the Canon EF 24-105mm f/4 IS II would be a superb lens. I was particularly expecting improvement at 105mm, which was the weak point of the original lens.
And, I usually put my conclusions at the start of an article so those of you who don’t like MTF graphs and spirited discussion about optical results don’t have to scroll down to the bottom. The new Mk II version is a bit better than the original version, but I was expecting a lot more. I wouldn’t rush out and upgrade from the 24-105mm f/4 IS if your goal is amazingly better optics. There may be other reasons to do so, but optics is not it.