Roger at Lensrentals.com has completed his MTF testing of the brand new Canon EF 24-105mm f/4L IS II.
From Roger
As always, I remind you that this has been an MTF test; it was only an MTF test. Had this been an actual photograph you would have been instructed that all differences were simply because of poor technique.
But on the basis of MTF, the 24-105 f/4 IS II is a decent lens, but not a spectacular upgrade. Would I upgrade my old 24-105 f/4 IS? Nope. If I was in the market would I buy one? Well, I’d wait for the price to come down or for it to be available as a kit lens with a new camera. One other thing to consider is that the new 24-105mm is significantly larger than the original version, and for some people, that’s going to be a negative for a walk-around lens. Read the entire article
We were hoping that Canon would continue their run of big improvement over previous iterations, such as the EF 16-35mm f/2.8L III and the EF 100-400mm f/4.5-5.6L IS II. However, at the price point of the EF 24-105mm f/4L IS II, we're not surprised to see only moderate improvement.