We make our choices, right? (No, straight...) Right!
"Sixteen" is the focal length... I'm using the lovely Sony a7RMk2 with my Sony 16-35mm f/4.0 lens at 16mm... 16mm is a challenging focal length, it allows you to bend and stretch as you see fit - my feet aren't really that big. Honest.
I've included a snapshot of the 16mm factor, below, if you're interested.