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Canon EF 135mm f/2.8 SF - Review / Lab Test Report - Analysis |
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Lens Reviews -
Canon EOS (APS-C)
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Page 2 of 2
Distortion
As to be expected from a tele fix-focal lens the level of distortion
is very low and nothing to worry about under field conditions.
135mm:
The chart above has a real-world size of about 120x80cm.
Vignetting
On the EOS 350D with its reduced format (APS-C) the (full format) lens
exhibits slight vignetting at f/2.8 which shouldn't be problem in most scenes.
One stop down the issue is negligible.
MTF (resolution)
The lens may be a little dated but with disabled soft-focusing it delivers
very respectable resolution figures under lab conditions. At wide-open
aperture the center performance is very good with good borders. From
f/4 & up the center is excellent with steadily increasing borders which
reach their (also excellent) peak resolution at f/8. The lens is
marginally worse than the EF 100mm f/2.8 USM macro and EF 135mm f/2 USM L.
Please note that the MTF results are not directly comparable across the different systems!
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 Imatest Explanations
Chromatic Aberrations (CAs)
Similar to most other fix-focal lenses chromatic aberrations (color shadows at
harsh contrast transitions) are very low and no real issue.
Verdict
The Canon EF 135mm f/2.8 SF may be old but it was still able to
delivery very good performance figures in all aspects. Nonetheless
there´re many lenses including zooms which are capable to deliver
similar and even better. So at the end of the
day the only real differentiator is the soft-focus feature. On paper
it may be worth a thought (if this is your thing) but if you´re into
digital photography you should be able to achieve a similar effect
using Photoshop. A real plus is the very affordable price though.
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