Well tell me why it is not the RF 16mm.
and don't you know it'll pop out a bit at powering on?
View attachment 204173
My mistake, you're absolutely correct.
Well, sort of Canon's mistake but I should have looked more carefully at the specifications. The Canon USA page reports the dimensions as
Maximum Outer Diameter x Length
Approx. 1.6 in. x 2.7 in. (40.1 x ø69.2mm); diameter is listed first in the header, but second in the actual measurements. B&H (where I think I looked for the specs) leaves out that rather important slashed-O next to the 69.2mm value that indicates diameter, and therefore reversed the measurements completely:
Had I thought about it, I'd have realized the diameter of the lens cannot possibly be 40mm, since the throat diameter of the RF mount is 54mm.
Thinking the length of the RF 16/2.8 lens was 69mm based on B&H, with the patent length 63mm but subtracting the flange distance yielding a lens of ~43mm, is what led to my questioning.
The optical formula length in the patent is consistent with the existing RF lens.
Good catch on your part, these 'new APS-C pancake lenses'...aren't.