Sigma AF 55-200mm f/4-5.6 DC - Review / Lab Test Report - Analysis
Lens Reviews -
Canon EOS (APS-C)
Wednesday, 26 December 2007 21:15
Page 2 of 2
The level of distortion is Ok with slight barrel distortion at 55mm
changing to quite pronounced pincushion distortion at 105mm and 200mm.
The chart above has a real-world size of about 120x80cm.
Typical for most true APS-C lens there's some vignetting (~0.65EV) at
wide-open aperture throughout the range but it's not quite as
pronounced as with other APS-C lenses that we've seen here lately.
As usual it helps to stop down a little to improve the issue.
The lens exhibited a surprisingly good performance regarding resolution.
It is already very good at wide-open aperture throughout the range.
At 55mm and 105mm the lens did even manage to reach excellent levels
at medium aperture settings.
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
The lens produced a varying degree of chromatic aberrations (color shadows at harsh
contrast transitions) at the image borders. At 55mm the issue is basically non-existent
and at 105mm it's still quite well controlled. However, at 200mm the problem is more
pronounced with an average CA pixel width of around 1 pixel.
Please note that CAs can be (auto-)corrected via imaging tools.
The Sigma AF 55-200mm f/4-5.6 DC is a budget lens and it shows in some aspects such as
small max. aperture combined with a limited zoom range and some mechanical shortcomings
(rotating front element and coupled focus ring).
Nonetheless the lens is also capable to deliver quite impressive resolution results.
So if you can live with its shortcomings and you just can't spend more for a faster
or longer tele zoom the Sigma is a viable option.