Canon EF 11-24mm f/4 USM L - APS-C Format Review / Lens Test - Analysis
Lens Reviews - Canon EOS (APS-C)
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The Canon lens shows some significant barrel distortion at 11mm on full format cameras. However, the issue eases drastically in the APS-C scope. At 11mm the barrel distortion is very moderate at ~1.5% and it's a non-issue at longer focal lengths really.


The same sweet spot advantage plays its magic in terms of vignetting. The issue isn't negligible at f/4 but not really extreme either even at 11mm. From f/5.6 onward, there's nothing to worry about.

MTF (resolution)

Honestly we weren't THAT impressed by the Canon EF 11-24mm f/4 USM L on the EOS 5Ds R but the task is much simpler on an APS-C format camera such as the EOS 7D II. The center quality remains absolutely stellar throughout the focal length range and at all relevant apertures. The good news is that the corners are also very good with no sign of weakness even at f/4.

The centering quality of the tested sample was good but not perfect.

Please note that the MTF results are not directly comparable across the different systems!

Below is a simplified summary of the formal findings. The chart shows line widths per picture height (LW/PH) which can be taken as a measure for sharpness. If you want to know more about the MTF50 figures you may check out the corresponding Imatest Explanations

Chromatic Aberrations (Border CAs)

Lateral CAs (color shadows at hard contrast transitions) are a weakness on full format cameras and they aren't all that great in the APS-C scope either. In the low to mid range, the CAs are clearly visible with an average width of roughly 1.5-2px at f/4 and slightly less so when stopped down as well as at the 24mm setting.


The Canon EF 11-24mm f/4 USM L may have some weaknesses on full format cameras. However, thanks to the sweet spot advantage on APS-C cameras, the situation is much different here. Resolution-wise the center remains breathtakingly sharp, of course, but the outer image region is now very good even at max. aperture. There's a bit of vignetting visible at f/4 but the issue is gone at f/5.6 already. In critical scenes you may observe a moderate barrel distortion at 11mm only. Lateral CAs remain somewhat higher than expected but this aspect can be fixed losslessly during post-processing.
Most ultra-wide angle lenses suffer from extreme flare in back-light conditions. Now the Canon EF 11-24mm f/4 USM L isn't perfect here - perfection simply doesn't exist here anyway - but it is a magnitude better than most other lenses that are at least capable of touching a similar focal length range. While we haven't tested the quality of the bokeh formally, we'd say that it is, again, better than most in this class (where most lenses perform dismal in this respect) although you will be able to see a bit of smearing and outlined highlights.

The build quality is exceptionally high and absolutely pro-grade. However, even though the lens body may be tough, the huge front element remains vulnerable. Due to its bulb-like shape protection filters are not possible. The new fluorine coatings will at least help to keep it reasonably clean most of the time. Remember that this is a massive lens both in size (well, diameter) and weight so it isn't exactly aligned to casual shooting really. Unsurprisingly the AF is very fast and near silent thanks to a ring-type USM drive.

Now all in all this sounds pretty good actually but the truth remains that the lens isn't really all that special anymore in the APS-C scope. Thus if you plan to stay in this format it's probably not worth to spend this amount of money. However, if you are using both formats or plan to upgrade, the Canon EF 11-24mm f/4 USM L is a viable option.

Optical Quality:
Mechanical Quality:
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