See also Compared to other Canon 35mm lenses. Canon RF 28-70 f/2L USM and EF 24-70 f/2.8L II USM. bigger. Canon 24-70/2.8 L II, 35mm f/1.4 L, 35mm f/2 IS and 35mm f/2. enlarge. If you want the most extraordinary optics overall, especially great sunstars and low distortion at 24mm, get this new 24-70 L II. Canon EF 16-35mm f/4L IS USM Lens. B&H # CA16354LEF MFR # 9518B002. 425 Reviews. Key Features. EF-Mount Lens/Full-Frame Format; Aperture Range: f/4 to f/22; Canon EF 24-70mm f/2.8 L USM set to 40mm (Metal 77mm filter thread, 1.25 feet/0.38m close-focus, 32.1 oz./910g, about $1,400 used.) enlarge. This free website's biggest source of support is when you use these links , especially these directly to it at Adorama or at Amazon , when you get anything, regardless of the country in which you live. I don't know how good the f4 version of the 16-35mm is, since I have never used one. I do know I will not buy a f2.8 16-35mm version again. I do have that version and replaced it with the excellent Tokina 16-28mm f/2.8 FF Lens for Canon EF. You will like the Tok! Micro UltraSonic Motor (USM) f/2.8 constant maximum aperture ; Super Ultra-low Dispersion glass; inner focusing; aspherical lens; full-time manual focus ; EF mount; ultra-wide zoom lens ; 16-35mm focal length ; EF mount; ultra-wide zoom lens ; Super Ultra-low Dispersion glass; inner focusing; aspherical lens; full-time manual focus f /2.8L f /3.5–4.5 Image Key features Image stabilizer No Environmental Sealing No USM No Yes L-series Yes No Diffractive Optics No Technical data Maximum aperture: f /2.8 f /3.5–4.5 Minimum aperture: f /32 f /22–27 Filter diameter 72 mm 77 mm Horizontal viewing angle: Vertical viewing angle: Diagonal viewing angle: Physical data Weight 570 g In the side by side image you can see the size difference in the two lenses. The 17-40mm lens is 0.63 inches shorter and weighs about 0.3 lbs less than the 16-35mm lens. The 16-35mm f/4L IS USM lens has 16 elements in 12 groups while the 17-40mm lens only has 12 elements in 9 groups. The 16-35mm f/4L IS USM is FULLY weather sealed while the 17 rMKC7.