So, new lenses are always fun and Canon recently announced the 70-200 f/4 IS II and 70-200 f/2.8 III. I consider both the lenses these updates are replacing to be classics, among the best Canon has to offer. The update to the 70-200 f/2.8 III sounds like it is more about coatings (maybe there is more, but so far, coatings...and a slightly different color of white), the 70-200 f/4 IS was updated with a new optical formula.
Bryan just released his first take on the IQ...I have to say, I see a bit of an improvement to contrast (most prominently at 135 mm), but this is very slight.
@ 70 mm:
https://www.the-digital-picture.com/...mp=0&APIComp=0
@135 mm:
https://www.the-digital-picture.com/...mp=2&APIComp=0
@200 mm
https://www.the-digital-picture.com/...mp=3&APIComp=0
Granted, that is the issue with trying to update a classic lens, it is already so good. And a bit better contrast could actually result in a noticeable improvement in some pics.
I do not own the 70-200 f/4 IS, but I own and I really do like the 70-300 L....you can see the improvement of comparing the 70-200 f/4 II and 70-300 L at 200 mm:
https://www.the-digital-picture.com/...mp=3&APIComp=2
While the 70-200 f/4 IS II and 70-300 L are similar in my mind (compact, light weight telephoto lenses), the 100-400L II and 200-400 f/4 are bigger and much bigger, but still, it helps to compare IQ at 200 mm:
https://www.the-digital-picture.com/...mp=2&APIComp=2
https://www.the-digital-picture.com/...mp=0&APIComp=0
Overall, it is not hard to see why the 70-200 f/4 IS was a classic. I am all set, but looks like a nice lens.