Here is a Canon RF 100-400mm f/5.6-8 IS review. One of the less expensive lens…
At a glance:
- EF-Mount Lens/Full-Frame Format
- Aperture Range: f/2.8 to 22
- Three Aspherical & Two UD Elements
- Subwavelength & Air Sphere Coatings
- Ring-Type Ultrasonic Motor AF System
- Internal Focus; Full-Time MF Override
- Fluorine Coating on Exposed Elements
- Dust- and Water-Resistant Construction
- Rounded 9-Blade Diaphragm
Specialized lens testing site photozone posted their analysis of the new Canon EF 16-35mm f/2.8L III, a highly regarded professional lens that comes at $2,199. The EF 16-35mm f/2.8L III was tested on a Canon EOS 5Ds R.
From the conclusion:
The Canon EF 16-35mm f/2.8 USM L III is, of course, an improvement over its predecessors. If you stop down a bit you can achieve edge-to-edge sharp images at all focal lengths even on a 50 megapixel camera. That’s quite an achievement! The image corners are a bit soft at f2/8 and the extreme ends of the zoom range though. However, in real life that’s rarely a showstopper. If you are using a camera with a more moderate pixel count, you don’t really need to worry because the lens is plenty sharp enough in this case. Lateral CAs are generally very well controlled. A substantial weakness is the amount of vignetting at the wide end though. When designing a lens you have to balance the different optical aberrations and Canon obviously decided to favour sharpness over vignetting this time. Read the review…
The review comes with MFT and distortion charts, images samples and plenty of information about this lens.