The Nikon is significantly longer than the Sigma and is the only current comparable lens that weighs more, though only very slightly so. Magnification from wide angle through standard/normal focal length lenses, including this one, is generally significantly increased with the use of extension tubes which are basically as their name implies, hollow tubes (with electronic connections) that shift a lens farther from the camera.

24-70mm F2.8 DG DN | Art | Lenses | SIGMA Corporation

The focal length range is highly useful, as is the wide aperture and the AF system may be my new Sigma favorite.

The good news about the 24-70mm focal length range, considered "normal" and covering angles of view ranging from wide angle through short telephoto, is the great general purpose usefulness it has. The graph below shows the degree of corner shading visible in images from the three lenses at their longest focal length and widest aperture (when it will be most noticeable). Sigma USA's provides a 3-year limited warranty (Sigma's international limited warranty is 1 year and Sigma USA adds a 3-year extension). Full frame lenses always show peripheral shading when used at their widest apertures on full frame cameras and this one is no different. The Tokina has about .5 stops less peripheral shading at f/2.8, though stopping down largely eliminates this difference.

Sigma 24-70mm f/2.8 EX DG HSM Interchangeable Lens Review Sigma 24-70mm f/2.8 EX DG HSM Interchangeable Lens Review

Optically, the Sigma 24-70mm f/2.8 IF EX DG HSM lens is rather weak when used wide-open. This is a shame given that the primary advantage of any fast lens is the ability to take advantage of low aperture numbers – but from f/4 right through to minimum aperture its MTF figures are above the critical 0.25 cycles-per-pixel threshold. Similarly, there is some distortion at all focal lengths but at no stage does the distortion become obtrusive. The two Sigma lenses perform similarly, with the Art having slightly less barrel distortion between 24mm and 28mm and slightly more pincushion from 35mm to 70mm. However, it’s only likely to be noticeable above ±0.5% with linear picture elements running parallel and close to the edge of the frame. The Sigma 24-70mm f/2.8 DG OS HSM Art Lens is available in Canon (reviewed), Nikon and Sigma mounts and the Canon mount version can be used on a Sony E-mount camera body via theThe Canon's rear-positioned zoom ring is a much better design, but for sure you will like the Sigma's roughly-25%-lower price tag better. Sigma USA's 4-year warranty is far superior to Canon's standard 1 year warranty (Sigma's international warranty is also 1 year). Summing this lens up in a paragraph or two is actually quite difficult, as it's almost like I've tested two completely different lenses at once. The first one being an f/2.8 zoom lens, which should be great for low light photography, but unfortunately falls slightly below par in terms of performance, especially at focal lengths beyond 35mm. Here the resolution at maximum aperture just isn't what you'd expect for a flagship lens from any lens manufacturer. So in summary, if you were after a high performance f/2.8 lens, you may find better performance elsewhere. On the other hand, if your photography allows you to stop down to f/4 or smaller much of the time, then this lens is a superb performer. There is no shortage of 24-70mm f/2.8 lenses to compare the Sigma Art option to and that creates a decision-making challenge.

24-70mm F2.8 DG OS HSM | Art | Lenses | SIGMA Corporation 24-70mm F2.8 DG OS HSM | Art | Lenses | SIGMA Corporation

But, you are probably not considering this lens if you only plan to use an f/4 max aperture because in that case, you are better off with the image stabilized The front lens element has a water- and oil-repellent coating that aids in keeping the lens clean and makes the lens easier to clean if something does adhere. But in other cases, I need several paragraphs to explain the complicated image quality a lens delivers. The visual similarities have led to speculation that this is just a re-housed Sigma lens, and while this is certainly a discussion worth having, we think we’ll save that for a separate “ PetaPixel Compares” story. For now, we’ll focus on the merits of the Leica lens alone. Even if the optics are the same as within the Sigma lens, the Leica version does have a slight advantage in the durability department that comes from having a metal housing. It is also slightly heavier than the Sigma lens as a result. Build Quality and Design Framing narrower on APS-C cameras (full frame 36-105mm equivalent angle of view), the 24-70mm lens' uses shift away from wide angle landscapes/cityscapes/nightscapes and environmental portraits toward portraiture including more tightly-framed portraits.If you can accept the loss of stabilization and performance wide-open, the Tokina has an overall performance similar to the Sigma lens, yet boasts slightly higher peak sharpness, excellent transmission, and good control of lateral chromatic aberration. Conclusion: Good value for money for Nikon users 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.