Marketed	December 2018
Original Price	1,680,000 yen
Lens Construction (group)	13
Lens Construction (element)	17
No. of Diaphragm Blades	9
Minimum Aperture	32
Closest Focusing Distance (m)	2.5
Maximum Magnification (x)	0.17
Filter Diameter (mm)	52
Maximum Diameter x Length (mm)	163×343
Weight (g)	Approx. 2,840

The EF400mm f/2.8L IS III USM successors to the EF400mm f/2.8L IS II USM (released in March 2011), which garnered high praise from users. Part of Canon’s L (luxury) series of high-performance lenses that realize superlative handling and operation, this lens achieves high image quality and significant reductions in weight, meeting the shooting needs of professionals working in such fields as sports, news reporting and landscape photography.

In addition to an overall optical rework, the mechanical structure of these lenses have been completely revised, including the introduction of an electronic focus ring. Through these changes, this lens maintains high image quality equivalent to the renowned quality of their predecessors while achieving drastic reductions in weight¹—the EF400mm f/2.8L IS III USM weighs approximately 1.01 kg (over 25%) less.

Employing two fluorite lens elements and a Super UD (Ultra Low Dispersion) lens, the EF400mm f/2.8L IS III USM adequately reduce the occurrence of chromatic aberration to achieve high resolution and high contrast. What’s more, newly employing Canon’s proprietary ASC (Air Sphere Coating), the lenses suppress ghosting and flare, which degrade image quality. Additionally, the lenses employ such features as a new heat-resistant paint that prevents increases in temperature by reflecting the infrared light in sunlight and dust- and moisture-resistant² designs to achieve superlative basic performance befitting super-telephoto single-focal-length L lenses, which pursue the highest levels performance.

In addition to realizing image stabilization equivalent to five shutter speed stops³, the EF400mm f/2.8L IS III USM offer three manual focus speeds for users to choose from depending on their preference, as well as a function that allows users to quickly change focus between two focus points pre-selected by the user for enhanced shooting convenience.

1 The EF400mm f/2.8L IS II USM weighs approximately 3.85 kg. The EF400mm f/2.8L IS III USM weighs approximately 2.84 kg.
2 While the structure of the lenses make arrangements for dust and moisture prevention, they cannot completely prevent the entry of dust and water.
3 When used with the EOS-1D X Mark II. Based on CIPA standards.