Sigma 50mm f/2.8 EX DG Review

Many film lenses struggle to turn in decent-looking results when fitted to a digital camera, but not this one. Its resolution, when tested on an EOS 400D body, was excellent. There’s some slight softness at the frame edges at f2.8, but this clears up by f5.6. The centre definition is very good indeed, even at f2.8. With no visible distortion and only the faintest traces of chromatic aberration near the edges, this is an extremely good lens.

It does show its age in one respect, though. It doesn’t have Sigma’s HSM autofocus motors, so the AF proves noisy and slow, though this is to be expected to a degree with macro lenses because of the enormous focus range they have to cover. Owners of Nikon D40/D40x and D60 bodies, however, need to be aware that the Nikon version of this lens doesn’t have an integral AF motor, so they’ll be restricted to manual focus only.

The manual focus is very, very good, incidentally. It’s a direct, mechanical movement and doesn’t have the somewhat ‘disconnected’ feel of more recent lenses. There’s a clearly-marked distance scale, and depth of field markers for shooting at f32. Depth of field is a constant problem in macro photography, hence the emphasis on tiny apertures. It is noticeable, though, that diffraction effects are taking the edge off the definition even at f16, though it’s still holding up pretty well and this lens is clearly optimised as far as possible for smaller apertures. It’s one of the known trade-offs in macro photography – outright definition versus depth of field. 

One other point worth mentioning is that on an APS-C digital SLR, this also makes a rather good 80mm equivalent ‘portrait’ lens. Its f2.8 maximum aperture is wider than most kit lenses at an equivalent focal length, so you can get attractive shallow depth of field effects very easily – and with decent definition at the same time.

The finish, build quality and controls are all very good, especially considering the price, and unless you’re dead set on sticking to own-brand lenses for your digital SLR, this Sigma has surely got to be near the top of your list when you go shopping for macro lenses.