I‘ve had the opportunity to try a few dives with the Canon EF 16-35mm f/4.0L IS and I am thrilled with the results. As much as I love shooting fisheye lenses for wide angle, such as the Canon EF 8-15mm f/4.0L, it is nice to change up the look with a rectilinear lens.
The 16-35mm focal length on a full frame camera is extremely versatile underwater. At the 16mm end you can capture large seascapes and at the 35mm end, the close focusing distance of only 11” allows you to fill the frame with sea stars and other small subjects.
This lens is tack sharp! I do notice a slight improvement over my Canon EF 16-35mm f/2.8L II. So if you don’t need to shoot wide open at f/2.8, getting the f/4.0 version is an easy decision. It also retails for $500.00 less than the f/2.8.
The Canon EF 16-35mm f/4.0L is about the same length as the f/2.8 but it uses a much more common filter size of 77mm compared to the f/2.8 82mm filter size. This enables me to share filters for topside photography with some of my other favorite lenses like the EF 70-200mm f/2.8 IS, EF 24-105mm f/4.0L IS and the new EF 100-400mm f/4.5-5.6L IS II.
The EF 16-35mm f/4.0L IS lens also features Canon’s optical image stabilizer making it an excellent lens for video and minimizing the appearance of camera shake by up four stops!