Originally Posted by
WhyFi
**** if I know. I guess that if I see anything deeper than 40mm I assume it's for some kind of aero benefit.
A modern, wide, blunt/ rounded 30mm aluminum rim is
faster than an old-school, 40-46mm, narrow V-notch. Think of it like an 80D vs your 5d. Crop sensor... but advanced enough to have better high-ISO despite its smaller size. Gets back again to, are you after performance or looks?