Sigma 70-300mm f/4-5.6 APO DG Macro - £180/$240
You'd normally reach for a telephoto zoom when you want to shoot distant objects, but the Sigma 70-300mm f/4-5.6 APO DG Macro is also designed for close-up work. In the 200-300mm zoom range, you can engage the lens's macro switch which shortens the closest focus distance from 150cm to 95cm, enabling a 0.5x maximum magnification factor.
Other attractions include three SLD (Special Low Dispersion) lens elements intended to minimise chromatic aberrations, but it lacks optical stabilisation and the autofocus motor is a basic electric unit.
The front element both moves out and rotates during focusing. At least build quality feels pretty robust and the lens barrel features both focus distance indication and an additional scale for magnification factor.
The Sigma APO turned in good results in lab tests, with respectable sharpness and reasonably low distortion. Aided by the SLD elements, colour fringing is also quite low throughout the zoom range. Autofocus speed from the electric motor isn't quick, but it's no slower than with the Canon lenses that feature ultrasonic motors.
The lack of image stabilisation makes handheld shooting a challenge on Canon and Nikon bodies, although it's less of an issue in Pentax or Sony versions of the lens, where you can use in-camera sensor-shift stabilisation.
The Sigma APO's main flaw is that it produces images with a marked lack of contrast in images taken under dull lighting conditions.
Sharpness test
Impressive, particularly at the centre of the frame through most of the zoom range, though there's a bit of a drop at 300mm.
Fringing test
Colour fringing is only an issue at 300mm and, even then, you need some very high-contrast edges in scenes to make it a problem.
Distortion test
There's almost no distortion at all at 70mm, although pincushion distortion is visible from mid-range to long focal length settings.
Image test verdict
The Sigma looks good on paper, but image quality is flawed by disappointingly low-contrast images in less than bright lighting conditions.
Read the full Sigma 70-300mm f/4-5.6 APO DG Macro review
