Sigma AF 105mm f/2.8 EX DG macro (Nikon mount) - Review / Lab Test Report - Analysis
Lens Reviews -
Nikon / Nikkor (APS-C)
Wednesday, 26 December 2007 19:56
Page 2 of 2
As to be expected from a fix-focal lens and especially for a macro lens the level of distortion
is quite negligible.
The chart above has a real-world size of about 120x80cm.
On the Nikon D200 with its reduced (APS-C) image format the (full format) lens exhibits very little vignetting
at f/2.8 and from f/4 & up the issue is absolutely negligible.
Typical for most macro lenses the Sigma AF 105mm f/2.8 EX DG macro performed great in the MTF lab.
The lens is already excellent in the center at wide-open aperture with marginally worse corners.
The peak performance is reached at around f/5.6 with an excellent center and border quality.
As usual diffraction is the limiting factor at smaller aperture settings. Extremely small
apertures such as f/32 should be avoided due to very pronounced softness.
The tested sample showed a slightly uneven resolution distribution.
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)
The Sigma shows an exceptionally low degree of chromatic aberrations (color shadows
at harsh contrast transitions) which are negligible in field conditions.
The Sigma AF 105mm f/2.8 EX DG macro is an excellent lens without any significant optical flaws.
The resolution figures are excellent and neither distortions nor CAs nor vignetting is
something to worry about. Similar to the Tamron or Tokina counterpart it is basically as
good as the much higher priced Micro-Nikkor (the classic one, not the VR). The build quality
feels very good although the implementation of the Dual-Focus mechanism isn't really
Regarding all the excellent lens alternatives in this segment it is quite
difficult to select a favorite ... but the good news is that there isn't really a wrong