I'm a wide angle guy. I love shooting grand landscapes using a wide angle lens. It's my style, vision, and it's how I view the world. So when Canon announced the 16-35 f4 IS I knew I had to test it out. I got my hands on one while I was in Tempe AZ. I had a chance to put it through it paces in Monument valley, Antelope Canyon, and the Grand Canyon. Here is the Canon 16-35 f4 IS review in my words. It's awesome!
I was a long time user of the 16-35 f2.8 II and this lens is far and away better optically. The corners of the frame are dang sharp, much more so than the 16-35 f2.8 II, (my lens copy was kind of terrible). I went through some older images and compared them to the images I made with the f4 IS. It's no comparison really. I am very pleased with the performance of this lens. Now the image stabilization is not really going to be used by me, I'm tripod mounted about 90% of the time, that other 10% I am shooting wildlife with a longer lens. The IS does seem quiet compared to the 24-70 IS and the 70-200 f2.8 IS II. I didn't do any tests on noise levels, just an observation. The focusing is smooth, precise, and it accepts 77mm filters! The legendary star burst effect that was present in the 16-35 f2.8 II is carried over to the f4 IS.
For a more complete and thorough review check out The Digital Picture. They have a great write up about this lens with a lot more detail and specifics.
As far as I am concerned this will be a hard lens to give up. I would love to see if Canon comes out with a 12-24 or something like that, but for now this is going to be my workhorse. Below is a finished image I made using the 16-35mm f4 IS at the Grand Canyon. Buy your Canon EF 16-35mm f/4L IS USM Lens here at Amazon.