Sigma AF 100-300mm f/4 EX HSM APO - Review / Lab Test Report - Sample Images & Verdict
Lens Reviews -
Canon EOS (APS-C)
Thursday, 27 December 2007 07:31
Page 2 of 2
Distortion is exceptionally well controlled with with marginal barrel
distortion at 100mm to marginal pincushion distortion at 300mm. The situation
remains as good when combining the lens with the Canon EF 1.4x II converter.
420mm (300mm w/Canon EF 1.4x II):
Typical for most full frame lenses it produces very little vignetting on APS-C type DSLRs.
The issue remains below 0.5EV at all focal length at wide-open aperture. Vignetting is
marginal in the 100-200mm range and slight at 300mm. Combined with the Canon EF 1.4x II
is issue is not field relevant again.
The lens was capable to deliver absolutely excellent resolution
figures in the MTF lab easily comparable to fix focal length lenses in their
respective range. At 100mm it even scratches the sensor limits of the 8mp sensor
of the test DSLR. At 200mm and 300mm the center resolution is already excellent
at wide-open aperture whereas the borders remain in very good
territory. Very impressive!
Combined with the Canon EF 1.4x II there's a (natural) drop in performance
down to a very good center and good borders.
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)
CAs (color shadows at harsh contrast transitions) are very low in the
native 100-300mm range with a maximum of 0.64 pixels on the average
at the image borders. The situation deteriorates significantly when
adding the EF 1.4x II resulting in already noticeable CAs widths of
around 1 pixel.
The Sigma AF 100-300mm f/4 EX HSM is the most impressive Sigma zoom lens tested to date. It is capable to deliver a near flawless performance with great resolution figures, low vignetting, low distortions, low CAs
and as a nice whipped cream on top the build quality feels just right. It also mates pretty well with the Canon EF 1.4x II converter at costs of relatively high CAs and a somewhat lower but still high resolution. All in all ... highly recommended!