Review: Sigma 70mm f/2.8 EX DG Macro

Taken with the Sigma 70mm f/2.8 Macro

DSLR lenses are specialized tools — they can open up new opportunities that point-and-shoot cameras can’t, but they also have some limitations. Usually the first way a new user discovers this is when they try and take very close macro shots that had worked great on their point-and-shoots, and finding out that the fancy new camera can’t focus anywhere near as close.

The good news is that there are a slew of specialized macro lenses for every model of DSLR. The bad news, of course, is that they cost more money. But the good news is that pretty much every macro I’ve ever heard of is exceedingly sharp, even from brands like Vivitar that don’t always inspire confidence. So what would it mean if a company released a lens so sharp that even users of all these other tack-sharp macros were surprised? And what if it were one of the cheapest lenses in its class?

At first glance, that’s exactly what Sigma seems to have accomplished with the 70mm f/2.8. Review after review have noted how sharp it is, even wide-open, from corner to corner. It sounded too tempting to resist, so I picked one up for myself. Here’s what you need to know about this lens:

  • Yes, it’s extremely sharp. Sharp enough to be noticeably better than even other amazingly good lenses, like my 24-70mm f/2.8. It also has nice color transmission and great contrast. I like sharp photos on the principle that you can always make things less sharp later, but it is noticeably unforgiving on human skin — the tiniest crows feet wrinkles show up even at f/2.8. It’s a perfect portrait lens for kids and a great focal length for headshots on APS cameras (equivalent to a 105mm lens, a classic portrait length), but you might want to have a good make-up artist around for adults. On the photo above, I purposefully left the clear-as-day fingerprint on the man’s ring to show you the precision that excessive sharpness requires.

    But remember, all macro lenses are pretty darned sharp. Unless you have a super-high resolution camera, like the new 14+MP APS cameras or the 21MP 1DS Mark III, the difference between them may not be all that noticeable, and other factors might matter more.

  • Good, smooth bokeh This is not true of many of the older macro lenses, and can be important because true macro images often have incredibly narrow depth-of-field. In the image above, the food stands out because of sharpness and clarity, but the specular highlights of the glasses behind blend nicely without being distracting.

  • Underwhelming autofocus It’s hard to make macro lenses with good autofocus, because there’s such a huge range between macro distance and infinity. What you see above is the Sigma 70mm focused at infinity on the left, and focused at 1:1 on the right. As you might imagine, it can’t rack all that lens back and forth very fast, so if your camera hunts through the range to find the right focus mark, you’re guaranteed to lose a few seconds of time, and possibly the photo you wanted. This makes it a much less useful lens for shooting moving objects than an internal-focus design like the Nikon 105mm f/2.8 VR Micro, which racks through its focus range comparatively quickly. The Sigma does have a focus limiter switch, but even then it’s not speedy. To save cost and size, it doesn’t have Sigma’s HSM in-lens focus motor, which means cameras in Nikon’s entry-level DSLR class cannot focus with this lens at all.

    The huge focus extension also means that when you are focused all the way in, you are incredibly close to your subject, close enough to knock your lens hood against it if you’re not careful. If you’re shooting animals who might be scared of a lens in their face, you might want something longer like Sigma’s 150mm f/2.8 Macro.

  • Poor lens hood design. If you like to use lens hoods, you might be disappointed at the outdated screw-on hood, which cannot be fastened to the lens backward for easy storage and which renders the lens cap pretty much useless. If you switch between lenses often, this makes the task of getting this lens ready for flare-free shooting much more onerous than it needs to be.

In short, this lens is an optical marvel, but it is a specialized tool for specialized tasks. The first thing to consider is whether you really need macro, or if you can make do with the close-focusing of your existing lenses. The second thing is to consider whether this lens hits the sweet spot of usability versus cost. You can probably easily find a used manual focus macro for dirt-cheap that performs admirably, but then you’ll lose focus (and maybe metering ability). You can also find a lens like the 105mm f/2.8 VR that’s more usable for non-macro shooting, but it costs a lot more money. If you want fantastic macro performance with autofocus at a good price, or you simply want absolutely ludicrous optical quality over AF speed, this lens could be for you.