An AFL button is included on the lens barrel, which can be customised depending on the camera and system.

If this concerns you; the only lens better is the remarkable 14-24mm f/2.8 AF-S zoom, which is much sharper in the corners at f/2.8 at 14mm. The 14-24mm is as sharp in the corners at 14mm and f/2.8 as this 14mm lens is at f/5.6. Distortion measures -0.38% barrel, quite a remarkable result for such a wide lens. It is no doubt sorted between lens and camera, but sorted it is.

The combination of a big f-stop and ultra-wide view makes for a hefty lens. The 14mm F1.4 DG DN Art's 19-element, 15-group optical formula results in a 5.9-by-4.0-inch (HD) barrel and 2.6-pound weight. It's a heavy lens to carry, especially if you've got others in your bag. If you don't mind giving up a half-stop of light, the Sony FE 14mm F1.8 GM is downright small by comparison (3.3 by 3.9 inches, 1.0 pounds). For reference, Sigma's 20mm F1.4 DG DN Art comes in at 3.5 by 4.5 inches, and 1.4 pounds. At intermediate apertures like f/4 and f/5.6, you’ll get some improvements, but f/8 is better. Upon stopping down to f/11 and particularly f/16, you lose sharpness throughout the frame due to diffraction (no different than any lens). Canon has replaced this cap with a plastic one (above right) that pinch-clips into a new raised rib inside the metal hood (visible in the lens comparison pictures).

It doesn't get softer wide open, since the aspherical design successfully eliminates spherical aberration. The car is relatively close, the right-most white light pole is a good distance away (and is the closest subject to the plane of focus) and the trees are much farther away.While the sealing in this lens is not different than the rest of Canon's weather-sealed non-super telephoto lenses, Thus my iffy converter was making 14mm perform poorly, while my old Tokina, which is a traditional design without any floating elements, wasn't messed up by the focus error of the converter. The 16-35mm II has a sharper light fall-off contour - it is not as smooth (better for cropped cameras). The 14 L II delivers a smoothly transitioning but somewhat strong amount of shading in full frame corners when shot wide open.

If you want numbers, analyzing these with the "info" box in Photoshop, the 14-24mm reference measures 1% saturation in the center, and only 2% saturation, 220 degrees hue (blue), in the corners. This 14mm measures 4% saturation at 35 degrees hue (slightly orange) in the center and 19% saturation at 200 degrees hue (blue-cyan) in the corners. Moving away from the center of the frame, there will naturally still be perspective distortion that causes a heavy skew on vertical lines as the lens is tilted upwards or downwards. However, because there is very limited barrel distortion with the straight lines, fixing this with only a perspective distortion correction is simple. A bulging convex front lens element and a built-in metal lens hood are identity features of this lens. From the comparison pictures, the Canon EF 14mm f/2.8L II USM Lens does not appear to be much different from the Canon EF 14mm f/2.8L I USM Lens.The 14mm II "features completely redesigned optics including 2 high-precision Aspherical elements and two totally new UD-glass elements." [Canon] Brushed finishes help enhance the natural character and texture of the wood by gently brushing it with a steel comb. You can then treat the flooring with oil or lacquer, as described below. Handscraped This is plenty close enough for dramatic perspective distortion, but this is not a high magnification value. Optical construction is 19 elements in 15 groups, including 1 SLD (Special Low Dispersion), 3 FLD (Fluorite-like Low Dispersion) and 4 Aspherical. FLD elements mimic the anomalous dispersion of Fluorite, but are lighter as well as being more affordable. The diaphragm consists of 11 blades to enhance bokeh as well as improving the rendition of stars as the lens is optimised for astrophotography. I did try it on my full-frame Canon 5D, and it looked bad. It looked worse than my 20 year old used Tokina 17mm f/3.5.