Comparison of Canon EF 16-35mm f/2.8L III USM and Canon RF 15-35mm f/2.8L IS USM

Attribute	Canon EF 16-35mm f/2.8L III USM ×	Canon RF 15-35mm f/2.8L IS USM ×
Aperture (f)	2.80 - 22.00	2.80 - 22.00
Filter Size (mm)	82	82
Notes	Image stabilization; dust and moisture resistant	For Canon RF-mount; Optical Image Stabilization (5 stops); Weatherproofing
Closest Focus (m)	0.28	0.28
Magnification Ratio (x)	0.22	0.21
Zoom System	Rotary	Rotary
Type	Wide Zoom	Wide Zoom
APS Equivalent	26 - 56mm	24 - 56mm
Diaphragm Blades	9	9
Image Circle	35mm	35mm (RF-mount)
Focal Length (mm)	16.00 - 35.00	15.00 - 35.00
Brand	Canon	Canon
Name	Canon EF 16-35mm f/2.8L III USM	Canon RF 15-35mm f/2.8L IS USM
Weight (g)	790	840
Diaphragm Blades Type	rounded	rounded
Lens Construction	16 elements in 11 groups, including 2 large-diameter double-surface GMo (glass-molded) elements, a ground aspherical element, and 2 UD elements	16 elements in 12 groups, including 2 UD and 3 aspherical elements; Fluorine coating on front and rear elements
Diagonal Angle of View (degree)	63.00 - 108.20	63.00 - 109.00
Length (mm)	127.5	126.8
Diameter (mm)	88.5	88.5
Focus Details	Inner focusing; AF with USM, full-time manual focus	Nano USM with full-time manual focus, AF/MF switch