Studio Tests - 35mm full frame
The 70-200mm F2.8 II really comes into its own on full frame, with highly impressive results at all settings. Again it's far better than its predecessor when shot wide open, and arguably provides the most consistently excellent results of any of the lenses in its class that we've tested so far.
Sharpness is extremely high, and impressively consistent right across the frame from center to corner. Truly excellent results are obtained at all focal lengths from wide open through to at least F11, beyond which diffraction gradually takes its toll.
Chromatic aberration is exceptionally low - there's a tiny bit of fringing measurable at each end of the zoom range, but really nothing you're ever likely to see.
We consider falloff to become perceptible when the corner illumination falls to more than 1 stop less than the center. Maximum vignetting wide open with this lens less than 2 stops at all focal lengths, with the pattern spreading progressively across the frame at longer focal lengths. The effect diminishes rapidly on stopping down, becoming insignificant by F4. Overall this is much what we would expect from this class of lens.
Distortion is still pretty low on full frame, at 1.2% barrel at 70mm, through neutral at 100mm, to 1.1% pincushion at telephoto. This almost perfectly matches the older version, and will only very infrequently be visible in real-world photos.
Specific image quality issues
As always, our studio tests are backed up by taking hundreds of photographs with the lens across a range of subjects, and examining them in detail. This allows us to confirm our studio observations, and identify any other issues which don't show up in the tests. The 70-200mm F2.8 L IS II USM quite simply delivered excellent results time after time, with very few foibles.
The 70-200mm F2.8 II has a complex optical design, and the profusion of elements in its construction would naturally be expected to result in some flare issues under unfavorable circumstances. Interestingly Canon has chosen not to use its latest 'Sub-Wavelength Structure Coating' in this lens, unlike Nikon which has applied its similar 'Nanocoat' technology to its 70-200mm F2.8 VR II.
Overall the Canon generally handles backlit conditions perfectly competently, aided in difficult lighting by its deep lens hood. Occasionally though it does run into serious issues with a strong light source either within, or just outside the frame that isn't shaded by the hood. With the sun in the corner of the frame we see extensive flare patterns which increasingly more defined and obtrusive on stopping down, whereas with the sun outside the frame but still impinging on the front element, there's a noticeable overall loss of contrast.
|70mm F16, Canon EOS 5D Mark II||200mm F4, Canon EOS 5D Mark II|
To be fair this isn't a particularly unexpected performance for this type of lens, and whilst these issues are easy to demonstrate when explicitly looking for them, they're unlikely to reflect very common shooting situations for many users.
Background Blur ('bokeh')
One genuinely desirable, but difficult to measure aspect of a lens's performance is the ability to deliver smoothly blurred out-of-focus regions when trying to isolate a subject from the background, generally when using a long focal length and large aperture. This is one aspect of the lens's character which looks like a step back compared to the older version - the bokeh has a tendency to be somewhat more 'busy', with harsher edges and less-smooth transitions between out-of-focus elements.
|115mm F2.8, Canon EOS 5D Mark II||150mm F2.8, Canon EOS 7D|
|25% crop||25% crop|
The 70-200mm F2.8 L IS II USM shows very low levels of fringing from lateral chromatic aberration in normal use. There's a little red/cyan fringing visible at 70mm if you examine images at 100%, and the tiniest hint of green/magenta fringing at the long end. Both are easily corrected in post-processing, if you're really critical about getting the very best possible results.
|F2.8, Canon EOS 5DMark II||F8, Canon EOS 5D Mark II|
|100% crop, left side of frame||100% crop, lower right|
Longitudinal chromatic aberration can occasionally be seen as well, as color fringing around slightly out-of-focus high contrast edges, visible mainly in close-up shots at larger apertures. The example below illustrates one of the most striking examples we found, which even then isn't particularly objectionable.
|200mm F4, Canon EOS 5D Mark II||100% crop|
Optical Image Stabilization
The 70-200mm features Canon's latest image stabilization system, which claims to allow hand-holding at shutter speeds up to four stops lower than usual before blur from camera shake becomes apparent. The mechanism is practically silent in use, with just-audible clicks when it activates and deactivates from the IS group moving in and out of the 'at rest' position. In fact the main indication the unit is running is the stabilization of the viewfinder image, which 'locks' very impressively when the IS is active.
We've generally found the stabilization units in SLR lenses to be pretty effective in real-world use, and to quantify this, we subjected the 70-200mm to our studio image stabilization test at the wide and long ends of the range, using the EOS 5D Mark II as the test camera. The subject distance for these tests was approximately 2m at 70mm, and 6m at 200mm.
We take 10 shots at each shutter speed and visually rate them for sharpness. Shots considered 'sharp' have no visible blur at the pixel level, and are therefore suitable for viewing or printing at the largest sizes, whereas files with 'mild blur' are only slightly soft, and entirely usable for less critical applications.
|70mm IS OFF||200mm IS OFF|
|70mm IS ON||200mm IS ON|
We're used to seeing Canon's latest IS systems do well in our tests, and the 70-200mm F2.8 II doesn't buck that trend. Under these controlled conditions, the IS system is delivering something pretty close to the claimed 4 stops of stabilization (for example, at 70mm we get similar results at 1/5 sec with IS on as at 1/80 sec with it turned off), which is about as good as things get at the time of writing. This also counts as an improvement of about a stop over the previous generation lens, which is definitely worth having.
Real world examples
To give some idea of how well the IS system works in the field, the samples below show the kind of slow-speed hand-held shots we were able to get in everyday shooting. Of course your results will depend upon many factors - you're likely to shake more if it's wet and cold, or have just drunk lots of coffee - but it's clear that Canon's IS works pretty well in practice.
|1/20 sec F5, Canon EOS 5D Mark II||1/40 sec F2.8, Canon EOS 5D Mark II|
|100% crop, center||100% crop, center|