Canon Lens EF 24mm 1:1.4 L USM

Aperture Range [f] 1.4 to 22 Closest Focus 0.25m / 0.82 ft.
Dimensions 77mm x 83mm / 3.0 in. x 3.3 in. Magnification Ratio 0.16x / 1:6.3
Weight 550g / 1.2 lb Filter Size 77mm

The lens has a wide range of apertures, from f/1.4 to f/22. Analysis of the 24mm lens resolution chart revealed that it is the sharpest at f/8. The image quality on a camera's chip depends on the distance from the center, as shown below, with the average resolution in hundreds of line widths per picture height (LW/PH) given below each chart.

lens quality test

At the full aperture there is a noticeably smaller contrast than at f/8. The red spot in the center chart is very slightly discolored, but it is relatively even in the higher aperture -made charts. For a standard digital SLRs the frame corner is around the 12th mm, so that the lens is very sharp for those types of cameras. For the full frame cameras there is a distinct loss of sharpness in a good portion of the picture. Towards the edges of the photo you can observe a variable resolution, depending on the lines direction, this is visible especially on the 18th mm top chart.
At the optimum aperture, f/8, the lens performance is excellent throughout the entire frame (resolution of "37" is the max. theoretical number in this test).

Vignetting is significant between f/1.4 and 2.0, but only for full frame cameras. Chromatic aberration is minimal, relative to its focal length. There is a 4% reduction of the circle diameter at the sides of the frame compared to the circle size at the center. This makes objects in the center appear slightly larger than on the sides.

If you are working in light challenging conditions, this is the the best wide angle lens available for Canon cameras, but for standard lighting you don't gain much, compared to the zoom lens EF 24-105mm, also described here as well.

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