Canon EF 50mm f/1.4 USM - Review / Test Report - Analysis
Lens Reviews -
Canon EOS (APS-C)
Page 2 of 3
As expected for a fix-focal lens the level of distortion is very low (but existent).
Note: the chart above has a real-world size of about 120x80cm - distortions may be more pronounced
at close-focus distances.
Despite the reduced image circle of the EOS 350D the (full frame) lens exhibits quite pronounced
vignetting wide-open. On full-frame DSLRs the problem should be even more critical. Nonetheless
vignetting problems aren't all that unusual with ultra-large aperture lenses and at least on APS-C
DSLRs the issue gets drastically reduced when stopping down a little. From f/2.8 & up the issue
is absolutely negligible.
The EF 50mm f/1.4 USM performed excellent in the lab with some of the highest resolution figures
obtained on the EOS 350D so far. It's quite safe to assume that the lens is capable to exceed the sensor
resolution here. The center resolution is already very decent at f/1.4 but the corners are quite
soft here. As usual stopping down towards medium apertures increases the quality and from f/2.8 is
results are superb. It should be worth to mention that the charts do only indicate a marginally
better performance (if any) compared to the cheap EF 50mm f/1.8 II (without any field relevance).
It is worth to mention that the lens suffers from low contrast at very large aperture settings. This
is quite normal and the colors are already snappy from f/2.8 & up.
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 (CAs)
Similar to most other fix-focal lenses chromatic aberrations (color shadows at harsh contrast transitions) are
very low and nothing to worry about.