I am a huge fan of my Canon 600mm f/4. The sharpness of that lens continues to blow me away. I realized that over the past few years all my wildlife pictures were taken between 400-800mm. My next in line lens fixed tele-lens was an old 300mm Sigma f/2.8 without IS.

Just received this from Adorama, great service by the way and thanks1! Haven't had a chance to use it yet in anger, but initial tests on a 1 Dx and 7D2 indicate that my 300 f 2.8 L IS mk2 may not see much use in future, this lens seems to be sharp as a pin, even with 1.4 and 2x mk3 extenders, and...

This is a sweet lens! Not only is it extremely lightweight, the images it produces are tack sharp, even at f4! I just shot for 3 weeks in Antarctica with this and it did not disappoint. Great for wildlife and landscapes. Mostly it was paired with my 7D Mark II giving me a boost in lens length.

Would prefer a f3.5 version of the DO lens. Because of price, plus size and weight, It would soon become the most popular telephoto for wildlife, just as it was for many years with Nikon.

I chose this lens as a compromise to get the maximum focal length against weight (and cost) as I tend to walk around when shooting wildlife rather than use a tripod or monopod. The 500mm f/4 is just too heavy for me to walk round with or hand-hold at eye-level for long periods.The 400mm f/4 DO can...

Relatively lightweight; f/4 max aperture allows a x2 Extender to be used

Expensive; Focus not the fastest with a x2 extender

I bought this lens because I have always wanted a DO lens but the first version of the 400mm DO was a little disappointing - based on online reviews. So when the Mk II was annnounced towards the end of 2014, I eagerly waited for some positive reviews.

Light weight; Good Optical Performance; Improved IS

Could be cheaper

Weighing in at about half the weight of a 400mm f/2.8 lens, the Canon EF 400mm f/4 DO IS II USM Lens immediately finds favor with sports and wildlife photographers looking for an easily hand-holdable, high-performance lens.

Specification A professional-grade telephoto lens, which sports a moderately fast maximum aperture of f/4, image stabilisation, silent focusing with full-time manual focus override and a relatively compact design, thanks to the use of Diffractive Optics.

A professional-grade telephoto lens, which sports a moderately fast maximum aperture of f/4, image stabilisation, silent focusing with full-time manual focus override and a relatively compact design, thanks to the use of Diffractive Optics.

Outstanding sharpness from maximum aperture; Low CA; Low distortion; Relatively compact; Excellent build quality; Effective image stabiliser

Price puts this lens beyond the reach of many

Put simply, the Canon EF 400mm f4 DO IS II USM is an outstanding super telephoto lens. Its use of cutting edge optical technology provides superb image quality with minimal light fall-off, no noticeable distortion and very high corner to corner sharpness.