As a member of the EX series of lenses this 3rd generation Sigma lens is designed with the highest level of optical technology and augments its predecessor with the addition of the Hyper-Sonic Motor (HSM) ensuring a quiet, high speed AF as well as full-time manual focusing capability. Housed in compact construction, the Sigma 24-70mm is a large aperture standard zoom lens ideal for all general photography including portraiture and landscapes. Physically, the shortest lens in the category, its overall length is 3.7 inches/94.7mm. With excellent optics, this could be the foremost performing lens in the category with stunning speed, clarity and color. Intricate lens construction includes Super Multi Layer Coating reducing flare and ghosting; the combination of ELD (Extraordinary Low Dispersion) and two SLD (Special Low Dispersion) glass elements and three Aspherical lenses provide excellent correction of all types of aberrations. Superior optical performance is ensured throughout the entire zoom range with the minimum focusing distance being 15in/38cm and maximum magnification ratio being 1:5.3. The rounded 9 blade diaphragm gives a natural look to backgrounds and foregrounds. Mark Amir, Sigma’s General Manager, says, “This new 24-70mm lens demonstrates Sigma’s commitment to producing lenses that offer the elusive combination of exceptional quality and high value and adds to the already wide range of critical lens selection.”
Dramatic improvement at top speed.
This top-drawer lens is fast and compact, with a practical focal-length range perfect for many of the subjects covered by event shooters and photojournalists in particular.
On our FX test camera, the lens did not really show impressive performance, however on DX the results are a lot more solid and convincing.
Center and border sharpness is generally very good, but there’s a visible drop in sharpness wide open and the extreme corners need smaller apertures to show good resolution.
Vignetting and CAs are very low and not really field relevant, except maybe CAs at 24 mm. The only real issue of the lens is it’s unpleasing bokeh. If your intended primary usage is to shoot portraits or seperate the main subject from a blurred and smooth background, you should probably look elsewhere. However, if you can live with or work around this issue or if you shoot stopped down mostly and just need the speed to have more reliable autofocus, the lens is a rather attractive option for a DX camera.