Before I start describing my experiences, I want to be clear that this is not a comprehensive technical review of this lens. There are countless reviews already on the internet, especially for these older model telephotos. In fact, I was not even planning to write about the two lenses I tried, the Canon 400m f/5.6L and the Canon 100-400 f/4.5-5.6L, but I developed such unexpectedly strong opinions about them, I thought it necessary. With that disclaimer out of the way, I can start!
Look and Feel
From the first moment that the Canon 400mm f/5.6L arrived, I was impressed. The build is solid and it is immediately comfortable to hold. It feels like you are holding a two thousand dollar lens. This feeling carries to the field. Whether I was trudging through the mangroves or crawling face down in the sand of the Cairns Esplanade, my thoughts never turned to the welfare of the lens. Even though I am insured, I still find it difficult to feel at ease with a plastic, rattly and fiddly lens. The balance while on the camera is perfect. On my Canon EOS 7D, it felt at home hand-held and on the tripod.
This aspect is often overlooked by those searching for a new lens. It is all well and good to obsessively peruse reviews and sift through hundreds of sample images, but without holding a lens in your hand, especially heavy telephotos, it is impossible to be sure of which lens is right for you. Of course, I am not one to pontificate on this particular matter, as I have spent many hours doing the former! It was the advice of a friend that prompted me to rent some lenses and I am now more than ever, immensely grateful for it. I had all but decided on a lens prior to the arrival of the rentals, but that decision went out the window once I had them in my hand. There is no way to know how a lens holds up when trying to shoot fast flying birds handheld or little brown jobs in murky rain forests, until you try it for yourself.
In every regard, the Canon 400mm f/5.6L was a pure joy to use. During the research, I was concerned about difficulties I might have hand-holding this lens. Its balance and design is such however, that unlike any other telephoto of similar focal length I have tried, which admittedly is not an enormous number, it was downright easy to keep this thing rock steady. Its girth, weight and the positioning of its focus ring are perfect. In the hand this was the clear winner for me. The only place I could criticise its build quality was its sometimes rattly built-in lens hood. While it locks when fully extended, it does not do the same when retracted. I would love to be able to better secure the hood in whatever position I choose and I would love it to have a tighter feel to it. This is a minor nitpick with an otherwise excellently built lens.
Operation
Although initially I was apprehensive using a telephoto of this length without image stabilisation, my concerns were alleviated once I took this prime out for a snap. Due partially to the fact the prime is generally a sharper lens than the Canon zoom, also because of some other key functional advantages.
The greatest advantage as far as I was concerned was the 400mm f/5.6L’s lighting fast focus acquisition. Much is made of this prime as a flight lens, of which it is more than capable, although my contention is the advantage of fast focus acquisition extends far beyond flight photography. Birds, more than any other subject, are fidgety, quick moving and unpredictable. I can’t write for anyone else, but as I do most of my bird photography stalking, I am forever chasing birds around the scrub. AI servo helps, but on the majority of occasions I have to refocus after some feathered wonder repeatedly escapes my frame. If you are planning to shoot predominantly stationary or slow moving subjects, the prime has yet another advantage — full time manual focusing.
Another consideration for me once I got my hands on this prime was to examine the relatively high minimum focus distance of 3.5m. I was very concerned that this could make shooting smaller subjects such as small passerines, impossible. As it pans out, my concerns were once again not warranted. It is a safe assumption that most birders using this lens, like me, will be using cameras with APS-C sensors. As this renders an effective focal length of 640mm on this prime, at 3.5m I had no problems framing even the smallest of birds. I suppose there could be a situation where a bird lands too close to focus on, but I found the distance to be shorter in practice than it appears on paper.
Optical Performance
One of the real standout aspects of this lens is its sharpness, even wide open. It is difficult to appreciate the impact of sharpness until you get your hands on a particularly sharp lens and compare it to an inferior one. One of the cornerstones of wildlife photography is having that critical sharpness in key areas, usually the eye. Despite objections by many to this sharpness obsession, personally, I usually immediately identify sharpness problems in an image and it usually completely ruins it for me — particularly in print. I can’t write to the preferences of others, but sharpness, along with distortion, will always be my premier considerations when buying a lens. In this regard, the Canon 400mm f/5.6L well outperformed my copy of the Canon 100-400 f/4.5-5.6L. I found it produced that critical sharpness far more consistently than the zoom, although the zoom can produce sharp images under optimal conditions. When it comes to corner sharpness, the gap between the prime and the zoom becomes enormous. The prime wins, hands down.
Unsurprisingly for a prime lens, the Canon 400mm f/5.6L produced no perceivable distortion or vignetting, particularly on my APS-C body. This reflects the more technical analysis provided in other reviews available such as Photozone’s comprehensive effort.
Verdict
The Canon 400m f/5.6L is one outstanding piece of glass for the money. It is sturdily built, ergonomically well designed, and optically impressive. When I first went to rent this lens, I was not really considering it as much as I should. When I had this lens in my hand, questions as to which telephoto I was going to buy flew right out the window. I can’t imagine this would be the same for everyone, as there are limits to its versatility. Although I did on a couple of occasions, I can’t imagine many people being comfortable with the prospect of walking around town snapping away with this beast, nor could I imagine it particularly useful photographing birds or animals in close quarters.
Just the same, the postman practically had to pry this lens from my hands. A wildly different experience than I had with the zoom. That’s all that matters in the end.















