This is the specific aperture required to enable the higher precision AF capabilities (most often the center AF point) in some cameras, further aiding in ideal image quality. At 200mm, the wide open center-of-the-frame performance is not quite as good, but this lens is still performing at least nearly as good as the best from an overall perspective.

Sigma 70-200mm F/2.8 DG OS HSM Sports Nikon FX

From 70-135mm, chromatic aberration was quite low, and extremely low in the vicinity of 100mm. It gets quite a bit worse at 200mm, but the average level actually wasn't too bad, as long as we stayed below f/16. Image stabilization has now been available in camera lenses for a long time, but I still love this feature and I often count on it making a clear improvement in my images. Most of the on-lens controls are grouped in a panel on the left side of the barrel. The Focus switches allows for full-time autofocus (AF), autofocus with manual override (MO), and manual focus (MF). There's also a limiter, so you can set the autofocus system to cover the full range or distant subjects (beyond 3 meters) only. The focus ring is ample, occupying the front three inches or so, and has set marks at 70, 100, 135, and 200mm. The zoom is internal—there's no barrel extension or retraction as the focal length is adjusted—which is a definite plus. You're still moving quite a bit of glass around, so a good grip is required—you won't be adjusting this ring with your fingertips. With 11 rounded aperture blades, this lens will create 22-point starbursts from point light sources when narrower apertures are used (f/16 in this case).

Canon shooters should think about spending more on the EF 70-200mm f/2.8 IS III USM when pairing with a high-resolution model or with an APS-C camera. But if you use a 20MP or 30MP full-frame model, the advantages of Canon's lens are lessened. There's a lot to love about this lens. With excellent detail at even wider apertures, great control over chromatic aberrations, very effective image stabilisation and prompt autofocus, it delivers what the professional demands at this level. Great build and weather sealing make it even more competitive, as does that price tag. It's not a cheap lens, but you get an impressive performance for the money. The addition of a Sigma TC-1401 1.4x Teleconverter creates an attractive full frame 98-280mm OS lens with the max aperture narrowing by 1-stop to f/4. The Nikon shows slightly less vignetting over the entire focal length range, has less barrel distortion at 70mm and better flare performance at that focal length as well (the two lenses are more similar at other focal lengths in those regards). Unless one is primarily using manual focusing, a lens' autofocus accuracy is very important for realizing the image quality a lens is capable of producing, especially with the relatively shallow depth of field this lens can produce at 200mm and f/2.8.

Sigma 70-200mm f/2.8 APO EX DG HSM Optical Stabilised

Containing a superset of the classic 85-135mm portrait focal length range, 70-200mm lenses are ideal for capturing pleasing perspectives of people. When using this lens for portraits, I love the bokeh -- my wife thinks it is a bit harsh, though. I will agree that it's no 85 f/1.4 ... Sigma's HSM (Hyper Sonic Motor) lenses are generally fast and accurate in their focusing, and this 70-200mm followed suit. The HSM motor also means you can grab the focus ring at any time and adjust the focus, you don't have to put either the lens or camera into manual focus mode first.

MTF Chart

Since 1982, PCMag has tested and rated thousands of products to help you make better buying decisions. See how we test. Look for the sharpest portion of the frame at f/2.8 with the details showing the least change at f/4 indicating the center of the plane of sharp focus. The pincushion distortion gradually increases until becoming moderately strong at 135mm and very slightly stronger by 200mm. From the charts I’d expect the lens to perform on a pretty high level regarding overall contrast but with limited sharpness at the short end outside the DX image-circle. Astigmatism seems well controlled. But let’s see how this theoretical performance translates into real life results in the sharpness test based on Siemens-stars. In the real world, lens defects do not exist in isolation with spherical aberration and spherochromatism generally found, at least to some degree, along with axial CA.