Think of a dedicated macro lens and chances are your first thoughts will be of one made by your particular camera-maker. All the big names make a range of focal lengths, usually based on the old 35mm film format with focal lengths of around 50mm, 100mm and 200mm. That’s fine if you have one of the full-frame DSLRs but if you’re selecting the coverage (or angle/field of view) based on one of these ‘classic’ focal lengths for an APS-C size cropped camera, you might just want to consider one of the ‘made for digital’ lenses. Typically these have shorter focal lengths to accommodate the APS-C sensor’s 1.5x-1.6x crop factor, and have been advocated by the independent lens makers especially - they’re usually quick to notice trends and announce new lenses, often well-ahead of the camera maker’s themselves.

The Sigma 70mm f/2.8 EX DG Macro is a good example of this. When paired with an APS-C DSLR it has the same angle/field of view as a ‘classic’ 105mm macro lens. However, it’s not just made for APS-C size digital cameras either, its image circle is large enough to cover a 35mm full-frame SLR, whether that be digital or film. So, the Sigma 70mm f/2.8 Macro is one of the most versatile of its type. As well shooting macro subjects to life size (1:1 magnification) and slightly more with a APS-C sensor, as a short tele, the 105mm equivalent focal length easily doubles as a portrait lens, allowing much tighter crops than a conventional portrait lens.

Sigma’s DG designation indicates they’ve paid particular attention to peripheral illumination, which is critical when using full-frame digital cameras but adds to the size of the barrel and to the cost of manufacturing. The 70mm Macro also boasts a pricey floating focus mechanism, arguably more informatively called close range correction by one rival but the economies of scale from selling the lens to a wide user base means it’s competitively priced. Indeed, the street price is around £375, which is even more surprising given the lens’ terrific optical performance.

Wide open there’s some vignetting but the Sigma is impressively sharp. Close down a stop to f4 and the lens really sings, albeit quite a bit more in the centre than edge. Indeed, with the exception of vignetting, after f4 the performance doesn’t actually improve, instead it declines gently but staying impressively high through to f11. As expected, definition starts to drop by f16 but even then it’s still excellent, with only the effects of diffraction, using the EOS 1Ds Mk III, being noticeable at f22. Thanks to three SLD (Special Low Dispersion) glass elements, chromatic aberration and is so low as to be hardly worth mentioning. And it’s the same story with distortion, it’s not noticeable in every day shooting but there’s a slight trace of pincushion. Sigma’s multi-layer coating is also noteworthy for its suppression of flare and ghosting, being easily on a par with the rival Nano Crystal Coat (NCC) from Nikon and SubWavelength structure Coating (SWC) from Canon.

That’s always a good thing, but it’s particularly relevant with this lens as the front element is quite exposed. A well-designed screw-in type hood is included in the price, which is great for filter use, particularly allowing polarizers, but it’s not particularly deep.

While the lens is quite a bulky affair on a small DSLR with a cropped sensor, such as the Canon EOS 550D, the ergonomics are still very good indeed. Along with the almost rubber–like coated feeling of the matte EX finish, a grip around the middle of the body ensures secure and easy fitting and removal, while the focus ring is both well-placed and smooth in operation. This last point will be of interest to macro-photographers, as AF systems aren’t really suited for ultra-close up use, especially when the subject is off-centre.

At other times autofocus is decidedly useful and the lens is both quick and accurate, if a little noisy in use. Sigma wisely includes a focus limiter operated by a chunky, well-placed switch that sits directly under your left thumb. This speeds up auto-focus operation preventing unnecessary hunting over the whole range, but it’s clever too in that the range is based on the position of the focus ring. When set to ‘Limit’ you can restrict the minimum focus distance to 0.55m for everyday use, or have the lens focus between 0.257-0.5m for macro work. That’s also the case when the lens is in manual focus mode.

If there’s a slight shortcoming to the design of the focus system it’s that the focus-ring doesn’t declutch, meaning it spins back and forth during autofocus, and you can’t switch between the two while it’s still moving. You must wait till it stops and use the AF/M switch. The lens also lacks the more modern IF (Internal Focus) design of rival marques as well as any optical image stabilisation, but if you’re a Sony or Pentax user (from the K10D onwards) the latter point isn’t going to be a concern.

Sigma has an excellent reputation for macro lenses, and yet the 70mm f2.8 EX DG Macro remains something of a hidden gem. While it’s true it lacks some of the more glamorous features of the camera maker’s offerings, if it’s sheer optical performance you value and you don’t want to break the bank, then this lens is a convincing alternative to the usual choices.

Final Verdict The Sigma 70mm f2.8 EX DG Macro is a gem and you don’t have to break the bank for it. OVERALL

Debbi’s passionate about all things photographic: from the latest digital kit to the greatest techniques to capture a scene. She’s been at the helm of the photography portfolio of magazines, websites and more for three years.