70mm f/2.8 EX DG Macro

Sigma have come up trumps yet again with a lens designed for the modern photographer. This time it is a macro lens, which is the ideal focal length for macro photography with a cropped sensor camera, but can also be used on full frame (35mm) cameras.

Specification

• Focal Length 70mm
• Aperture f/2.8
• Angle of view 34.3º
• Filter size 62mm
• Construction 10/9 elements/groups
• Focus type Floating system
• Closest focus 250mm (1:1)
• Weight 527g
• Dimensions 76x95mm
• Mounts available Sigma, Canon, Nikon (D), Sony, Pentax
• Tripod bush No
• Price (SRP) £339.99pBuild and Handling

  Click to see larger imageWith Sigma’s EX range, the build, handling and finish of this lens falls into the higher end of our expectations and this model does very little to disappoint. The matt black finish is now known, through extensive personal testing, to be hardwearing and the body of the lens feels robust enough for it to be put to some serious graft.

  The manual focus ring is nicely torqued and takes almost three quarters of a turn to move through the full focus range. This range however, does take the focus point down to 25cm and a full one to one image size. So it is a true Macro Lens. This does extend the length of the optic by some 52mm and reveals a reproduction ration scale on the single trombone poking out of the front. This trombone displayed no sign of play during this extension, even with some pressure applied.

  A focus limiter switch sits on the side of the barrel and operates on each side of a stop set around the half metre mark, restricting the distance the lens has to travel through during autofocus. It can be switched off to achieve full travel. Being designed as a macro lens, the AF is not lightning, due to the finer pitch of the focussing motor but with the limiter engaged, it is fast enough for most purposes. The is no HSM fitted, so it does make a little noise, but not annoyingly so.

  

  Physically, the lens is no smaller than it’s 105mm cousin, although it has lost the push-pull action of the focus ring needed to activate the manual/auto focus changeover. It has also lost the distance window, with distances now being marked on the focus ring.

  The lens comes supplied with a screw-in lens hood that gives the alternative of using popular sized 77mm filters on the end of the hood, and is packed in it’s own zip-topped semi-hard pouch that includes a belt loop.

  Optical Quality.
  Sigma’s reputation for top quality prime macro lenses is more than upheld here with this 70mm offering. Designed to have a similar useful range as the very popular 105mm lens on a full frame camera, the optical performance more than matches up too.

  The lens proved to be sharp right from the outset at f/2.8 and stays that way right through to between f/11 and f/16 where reciprocity starts to come in and degrade the image slightly. Even this though, is well controlled and there is no massive falloff as with some lenses. Taking modern methods into account, Sigma have restricted the minimum aperture to f/22, leaving the further two stops of its sibling out on the grounds that the image quality suffers too much from reciprocity.

  Distortion, measured with the Imatest™ distortion module is negligible with a reading of 0.17% pincushion, which is visually undetectable.

  Chromatic aberrations are so well controlled that similar, negligible readings were recorded throughout the aperture range and are as good at the edge as in the centre.

  Click to see larger imageI have mentioned before, Sigma’s DG coating, designed to reduce reflections from shiny sensors bouncing around inside the lens, and its positive effect on lens contrast. Well, I’m doing the same again here, as the contrast delivered by this optic is excellent. Colour reproduction is neutral; with no obvious casts and the incidence of flare never reared it’s ugly head in normal use.

  

  The focal length is an ideal one for portrait photography as well as the intended macro use and the nine bladed aperture does make for pleasant OOF backgrounds or bokeh.

  Verdict

  Long enough in its focal length to be useful for many forms of macro photography and virtually the ideal for portraiture (on a cropped sensor) the lens also lends itself to many other short telephoto uses too. Optically it is probably the best of Sigma’s already highly rated macro line-up, coming straight in with razor wide-open images. The lens is also capable of being used on ‘full frame’ sensors and 35mm cameras, so I should think it will find its way into a number of the photographically inclined’s inventories.