Canon EF 70-200mm f/2.8 USM L IS - Review / Test Report - Analysis
Lens Reviews -
Canon EOS (APS-C)
Wednesday, 26 December 2007 10:39
Page 2 of 3
The level of distortion is very low for a zoom lens - there is only very slight barrel distortion
at 70mm and absolutely negligible distortion at 135mm and 200mm.
The chart above has a real-world size of about 120x80cm.
Vignetting is very well controlled with the lens.
At 70mm and 135mm vignetting is already negligible at wide-open aperture.
At the long end it is a little more pronounced wide-open with ~0.6EV. Usually
not a problem except in very extreme situations. At f/4 the problem is
not field relevant anymore.
Two sample of this lens has been tested. The first sample performed quite poor and
the 2nd sample did outperform its quality figures but not without problems. This
2nd sample has been tested once more after a calibration by the Canon service.
In the lab the lens showed a very good (f/2.8) to excellent performance at 70mm and 135mm
However, at 200mm the resolution figures are not all that impressive for such a
high-priced product. The figures are generally still very good here but frankly
you can have a better performance out there. Regarding the fact that the lens
has been calibrated it is viable to state that the lens is not any better than
that. Regarding the quality figures at 200mm it does not seem to be advisable to
use this lens with converters without hefty performance penalties.
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
Chromatic Aberrations (CA)
The lens showed relatively pronounced lateral chromatic aberrations (color shadows at harsh
contrast transitions) with an average pixel width just below 1px at the image borders.