Sigma 70-300mm f/4-5.6 APO DG Macro - £200/ $239
Bearing Sigma's 'DG' designation, not 'DC', this lens is designed for both full-frame and APS-C D-SLRs. Its APO (Apochromatic) design includes no less than three SLD (Special Low Dispersion) lens elements in a bid to reduce chromatic aberration, and a 'Macro' badge shows the lens's close-focusing capability. The super-close focus is available in the 200-300mm zoom range via a switch on the lens barrel. This zoom setting and the minimum focus distance of 95cm deliver a0.5x macro facility.
For regular telephoto shooting, the absence of an optical stabiliser is a setback, and while the basic electric autofocus motor was fairly quick, it was quite noisy. The front element also extends and rotates during focusing.
Impressive throughout most of its zoom range, this Sigma lens's sharpness drops off at the long end of the zoom range, especially towards the edges of the frame. Sharpness at 300mm is poor across the whole frame at small apertures of f/16 to f/32, which you might want to use to increase depth of field in macro shooting. The lens's 'APO' badge proved justified, with low levels of chromatic aberration, though image contrast is often bad in low light.
Lab test results
At 70mm, the Sigma APO produces thebest sharpness result in our test. But detail levels drop at 300mm.
Fringing at all focal lengths and across the frame is minimal. Close analysis shows a faint green/blue edge.
This shows the least amount of barrel distortion at 70mm. Distortion across the rest of the focal range is average.
Image quality verdict
This lens scored two of the highest results for sharpness at 70mm and 135mm, and came second in the test for fringing and distortion.
Read the full Sigma 70-300mm f/4-5.6 APO DG Macro review