What is the maximum aperture at 400mm on the Canon RF 100-500mm f/4.5-7.1L IS USM?

Craig
1 Min Read

When you purchase through links on our site, we may earn an affiliate commission. Here's how it works.

A question that I personally wanted to be answered has been answered at The-Digital-Picture with the help of Canon USA.

The answer is actually quite interesting.

What is the Canon RF 100-500mm F4.5-7.1 L IS USM Lens's maximum aperture opening at 400mm?

Answer 1: When the camera is set to 1/3-stop increments, the maximum 400mm aperture is f/6.3.

Answer 2: When the camera is set to 1/2-stop increments, the maximum 400mm aperture is f/5.6.

Keep in mind that on variable aperture lenses, the camera doesn't read what the exact aperture is

I would hypothesize that the lens is actually something like f/6 at 400mm and the increment settings just decide how the camera reads the aperture. Rarely are apertures 100% accurate on variable aperture lenses. I haven't yet seen a patent with this exact optical formula to know what it is at 400mm from a design point of view.

Hopefully, Canon makes it easy to switch between 1/3 and 1/2 increments when using the Canon RF 100-500mm f/4.5-7.1L IS USM with your EOS R5 & EOS R6.

Share This Article
Follow:
Craig is the founder and editorial director for Canon Rumors. He has been writing about all things Canon for more than 17 years. When he's not writing, you can find him shooting professional basketball and travelling the world looking for the next wildlife adventure. The Canon EOS R1 is his camera of choice.
111 Comments

Leave a Reply