Coinciding with the announcement of the 5D Mark IV, Canon has introduced updates to two L-series lenses: the EF 16-35mm F2.8L III USM and EF 24-105mm F4L IS II USM. The 24-105mm F4L II offers improved image stabilization, claiming four stops to its predecessor's three, and adds air sphere coating for better resistance to ghosting and flare. Two aperture blades have been added, totaling 10 now - arguably one more than it should have for pleasing sunstar rendition.

The third iteration of Canon's 16-35mm F2.8L uses a large diameter GMO (glass-molded) dual surface aspherical lens. Like its predecessors the lens is water- and dust-resistant, and Canon claims the new lens boasts improved durability. We've seen some initial comparisons vs. the Mark II, and the Mark III clearly addresses one of its predecessors largest shortcomings - poor off-center performance - while arguably improving upon one of its most revered qualities: beautiful sunstars, now with 18 rays.

The EF 16-35mm F2.8L III USM will cost $2,199 and the EF 24-105mm F4L IS II USM will sell for $1099. Both lenses are scheduled for October availability.

From the press release:

New Canon EF Lenses and EOS Accessories
In addition to the new EOS 5D Mark IV DSLR, Canon is also introducing two EF-Series L-series lenses as well as a variety of EOS accessories. The new EF 16-35mm f/2.8L III USM Ultra-Wide Zoom Lens features a large diameter GMO dual surface aspherical lens and ground aspherical lens, f/2.8 aperture throughout the entire zoom range, fluorine coating, improved durability and is dust and water resistant. The new EF 24-105mm f/4L IS II USM Standard Zoom lens features an improved four-stop image stabilization as well as ghosting and flare reduction with air sphere coating. The Canon EF 16-35mm f/2.8L III USM Ultra-Wide Zoom Lens is scheduled to be available late in October for an estimated retail price of $2,199.00†† and the EF 24-105mm f/4L IS II USM Standard Zoom Lens is scheduled to be available in late October for an estimated retail price of $1,099.00††.

Additional EOS accessories include the Canon Battery Grip BG-E20, Canon Rain Cover ERC-E5S/E5M/E5L and Canon Protecting Cloth PC-E1. For more information about all these products and accessories, please visit: https://www.usa.canon.com/5D4Legend

††Availability, prices and specifications are subject to change without notice. Actual prices are set by individual dealers and may vary.

EF 16-35mm F2.8L III USM / EF 24-105mm F4L II USM specifications

 Canon EF 16-35mm F2.8L III USMCanon EF 24-105mm F4L IS II USM
Principal specifications
Lens typeZoom lens
Max Format size35mm FF
Focal length16–35 mm24–105 mm
Image stabilizationNoYes (4 stops)
Lens mountCanon EF
Aperture
Maximum apertureF2.8F4
Minimum apertureF22
Aperture ringNo
Number of diaphragm blades910
Optics
Elements1617
Groups1112
Special elements / coatings1 dual-surface aspherical, 1 aspherical + fluorine, Air Sphere, Sub-wavelength Structure coatingsFluorine and Air Sphere Coatings
Focus
Minimum focus0.28 m (11.02)0.45 m (17.72)
Maximum magnification0.25×0.24×
AutofocusYes
Motor typeRing-type ultrasonic
Full time manualYes
Focus methodInternal
Distance scaleYes
DoF scaleNo
Physical
Weight790 g (1.74 lb)795 g (1.75 lb)
Diameter89 mm (3.48)84 mm (3.29)
Length128 mm (5.02)118 mm (4.65)
SealingYes
ColourBlack
Zoom methodRotary (internal)Rotary (extending)
Power zoomNo
Zoom lockNo
Filter thread82 mm77 mm
Hood suppliedYes
Hood product codeEW-88DEW-83M
Tripod collarNo