3. Focus Speed and Accuracy
As a professional wildlife photographer, autofocus is one of the most important things that I look for in a lens/camera combination. These days even the most basic lenses offer a solid focusing performance, primarily when used in good light, but where the top of the line lenses come into their own (along with the better camera bodies) is in being able to focus accurately under challenging conditions. Conditions such as low light, fast-moving subjects, and complex backgrounds require lenses that make the most of the cameras tracking capabilities, and thankfully the Canon EF 70-200mm f/2.8L USM IS II excels in this regard.
An important aspect to consider when judging a lens’s focusing capabilities is that the camera body plays an integral role in the quality of the autofocus and due to this, it’s important to match your lenses with high-quality bodies that can deliver good focusing performance. I have been able to use the EF 70-200mm f/2.8L USM IS II alongside the reliable Canon 1Dx body whose exceptional focusing capabilities rank as some of the best I have experienced.
The overall focusing performance of the EF 70-200mm f/2.8L USM IS II is fantastic, with the lens snapping into focus almost instantaneously. In fact, I would rate the speed of the focusing on this lens on par with my Canon 300mm f/2.8L USM IS lens which has long been considered a benchmark for focusing speed in the EF mount. The EF 70-200mm f/2.8L USM IS II lens features Canon’s USM motor so focus operation is extremely quiet, with only a very slight whirr heard as the lens elements move inside. This lens also features an advantageous minimum focus distance of just 1.2m which makes it very good for close-up photography.
Initial autofocus acquisition is very fast, and I have no hesitation about engaging the focus system the moment the target is in the viewfinder. In good light, focus locks almost instantaneously onto the subject with almost no delay. The large f/2.8 aperture also means that focus speeds are excellent in low light situations. This is especially useful when taking photos at dusk and dawn or when hiking in dense forests where light levels are very dim. In such situations, the one-stop advantage of the EF 70-200mm f/2.8L USM IS II over lenses like the EF 70-200mm f/4L USM IS II becomes quite evident and I have found that I can get about eight extra minutes of shooting time at dusk when using the f/2.8 vs. the f/4 lens.
Focusing accuracy is also very high, and I feel that the EF 70-200mm f/2.8L USM IS II compares favorably with Canon’s best prime lenses in how well it can track fast-moving subjects.
When you mount an external Canon 1.4x Teleconverter, autofocus speed remains very high though focus accuracy takes a slight hit. In good light, you will be hard pressed to notice that the converter is in use, after all, you still retain an f/4 max aperture. When used in low light conditions, there is a slight, yet noticeable drop in the overall tenacity experienced when using the bare lens.
The below photograph of a rare Mountain Gorilla in Uganda was taken with the lens and an external Canon 1.4x Teleconverter, and it highlights how well the combination was able to focus through the dense undergrowth on the eyes of the subject.
When you mount an external Canon 2.0x Teleconverter, autofocus speed and accuracy is noticeably reduced. This isn’t as noticeable when you use the combination in midday lighting but can become quite sluggish in low light conditions. In good light and with the focus limiter engaged, you can successfully track difficult subjects such as the jumping Capuchin Monkey seen below with relatively high consistency. Unfortunately, I find that this combination becomes quite bad when trying to track fast-moving subjects during the wee hours of the day. Overall, while this combination is decent when used in good light, I have never been particularly happy with the overall performance of the EF 70-200mm f/2.8L IS USM II when its used alongside Canon’s 2x Teleconverter. The issue doesn’t seem to be with the teleconverter as I find it works great on the f/4 max aperture Canon 200-400mm f/4L IS USM lens.