Sharpness You Can See: Canon EF 24-70mm f/2.8L USM IIGear Talk
The much anticipated release of the Canon EF 24-70mm f/2.8L USM II has been the source of much discussion and debate. While the lens has some notable differences than the original Canon EF 24-70mm f/2.8L USM (we’ll cover those at the end) the #1 attribute of note is its sharpness.
How much sharper could it be you ask?
We ran tests to gauge image sharpness for each lens here at BorrowLenses.com headquarters and we were blown away by what we saw. The original Canon EF 24-70mm f/2.8L USM was considered to be a very sharp lens and what we found in our tests was that Canon made significant improvements in sharpness and chromatic aberation reduction in the Canon EF 24-70mm f/2.8L USM II. Seeing is believing, so check out the comparison images below to see for yourself how much sharper the lens is compared to the older model.
Note: The images below are essentially thumbnails that will show differences in lens distortion, vignetting, pincushioning, and in extreme cases sharpness. To properly see the differences in sharpness and chromatic aberration we recommend you click on the download link at the end of this post to view the full size images.
Our Testing Methodology
We placed the optical axis of the lens perpendicular to our Edmund Optics Resolving Power chart. This alignment neutralizes any sign of tilt that would misalign the plane of focus and exaggerate any softness in focus in the outer corners. Each lens was tested on a Canon 1D X with center point focus, mirror lockup and triggered after a 2 second delay to minimize any vibration that would add motion blur. Camera and lenses were positioned on a tripod to provide stability and consistency in placement in relation to the resolution chart.
Why f/2.8 and f/8
Lenses when wide open at f/2.8 exhibit the lowest amount of depth of field and often produce softer images when compared to smaller aperture settings. More importantly since our testing places our resolving chart in the sweet spot for focus across the focal plane you’re more apt to see softness resulting from any optical aberrations at this aperture setting. f/8 is a standard aperture settings used in manufacturer tests to create lens MTF charts that show degree of sharpness over a range of aperture settings from a sensors center to edge. Since f/8 is a mid-range setting you’re more apt to fall closer to a lenses optical sharpness sweet spot. (Recommended reading: How to Read an MTF Chart)
Sharpness Testing Observations
24mm at f/2.8
70mm at f/2.8
24mm at f/8
70mm at f/8
- Benefits of use are less notable on a cropped sensor camera, as the most dramatic resolving improvement are present in the outer corners of the image. Nonetheless, the previous model’s shortcomings in chromatic aberrations and resolution have been corrected.
- From our limited testing it would appear the older generation Canon 24-70mm f/2.8 lens has a slightly wider field of view, but to verify this we’d need to do more testing.
- The Canon EF 24-70mm f/2.8L USM II lens extends as it moves toward 70mm (telephoto end, as it should), rather than the reversed mechanism of the 1st generation lens.
- The build of the Canon EF 24-70mm f/2.8L USM II looks to be similar to the Canon 24-105mm f/4L USM, in terms of shape, but with materials that resemble the Canon 8-15mm f/4L USM Fisheye.
- The Canon EF 24-70mm f/2.8L USM II has less play in the zoom barrel, which was all-too-common in the first generation model and likely a contributor to the tilted resolution and chromatic aberrations.
- The hood mount has been moved from the barrel to the end of the lens allowing for a shorter lens hood.
- The lens hood mount has been relocated from the lens barrel to the end of the lens allowing for use of a shorter lens hood.
- The filter size of the Canon EF 24-70mm f/2.8L USM II has been changed to 82mm versus the 77mm of the 1st generation lens.
- The Canon EF 24-70mm f/2.8L USM II now has a zoom lock.
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