Why Sigma APO 70-200mm F2.8?

The 70-200mm F2.8 EX DG Macro HSM II is one of Sigma’s latest lenses, which was first announced in December 2007 for Canon, Nikon and Sigma, with a slew of follow-on releases adding compatibility for the remaining SLR mounts (i.e. Four Thirds, Sony and Pentax; however none of these versions are yet shipping). It’s a successor to the 70-200mm F2.8 EX DG Macro HSM of February 2006, with a refined optical layout offering improved optical performance, and becomes the fourth iteration of the same basic EX design first unveiled in 1999 (which was itself preceded by a well-respected 70-210mm F2.8 for 35mm). The HyperSonic Motor (HSM) focusing system promises fast, silent and accurate autofocus for users of all brands of DSLR, although Pentax users should be aware that this lens is effectively of ‘KAF-3′ mount specification, and therefore won’t focus on bodies which don’t support SDM lenses. Aside from that specific incompatibility, this is a design which will work on almost every DSLR ever made, and is therefore of unusually broad buyer appeal.

Sigma are fond of using a plethora of letters in their lens names (presumably on the principle that when faced with a choice, potential buyers will purchase the one with the most initials) and the 70-200mm declares its credentials accordingly. ‘EX’ stands for ‘Excellence’ and designates Sigma’s premium lens line, with superior build and optical quality, while ‘DG’ means that the lens coatings are optimized for use on digital SLRs, and the image circle covers the full-frame 35mm format. Finally ‘Macro’ is a pointer towards the closer-than-usual minimum focusing distance of just 1m, which compares favorably to the 1.5m more typical of lenses of this class, although it has recently been trumped by the 0.95m of Tamron’s SP AF 70-200mm F2.8 Di LD (IF) Macro.

Of course as one of Sigma’s flagship lenses, the 70-200mm F2.8 boasts a suitably complex optical design, featuring 18 elements in 15 groups, two of which are Extraordinary Low Dispersion (ELD) glass and two Special Low Dispersion (SLD) glass for correction of chromatic aberrations. Other attractions include internal focusing and zooming mechanisms, and a quick-release tripod mount collar which can be removed from the lens in seconds. On paper at least, this is a lens which might interest a huge number of photographers across a range of abilities; so is it worthy of that interest?

Sigma 70-200mm F2.8 EX design history

• 70-200mm F2.8 EX APO – Original version, minimum focus distance 1.8m (1999)
• 70-200mm F2.8 EX DG – Adds ‘digitally optimized’ lens coatings to reduce flare (2005)
• 70-200mm F2.8 EX DG Macro (HSM) – Minimum focus distance reduced to 1m (2006)
• 70-200mm F2.8 EX DG Macro HSM II – Improved optical performance (2007)

Headline features

• 70-200mm focal length range; fast F2.8 constant maximum aperture
• HSM (ultrasonic type) autofocus with full-time manual override
• To be available in Canon, Nikon, Four Thirds, Pentax, Sigma and Sony/Minolta mounts

It is possible to use both Sigma tele converters transforming the lens either in a 98-280mm f/4 (w/1.4x EX) or 140-400mm f/5.6 (w/2x EX) combination.

It is worth to mentioned that I tested the non-DG variant earlier this year but this sample suffered from a rather extreme centering issues. Even worse Sigma was unable to repair the problem.

So the choice is yours. If you are looking for a lens in the 70-200 or 75-300 range, save your money up for a fast 2.8 version with stabilization, you will not be sorry. Those less expensive f3.2-5.6 or lower lenses are just not as practical as a good 2.8 lens. If you can afford the Canon and don’t mind the black and white stripes, by all means get it, otherwise, get this one, you will be very pleased that you did.