In December 2009, the renewed Sigma 17-70 mm OS, fully named Sigma 17-70 mm 2.8-4.0 DC Macro HSM, was released. The new one is slightly faster (f/2.8-4) and is, equally important, equipped with image stabilization. A lens with a focal length of 17-70 mm is much more universal than a lens that does not go further than 50 mm in the outer zoom position. In portrait photography, 70 mm is in many cases a very convenient focal length. Interestingly, the Sigma 17-70 mm OS is the only lens with that zoom range at the moment. In 2013, this lens has been replaced by the Sigma 17-70 mm 2.8-4.0 DC Macro HSM Contemporary.
FOV Sigma 17-70 mm OS @17 mm
FOV Sigma 17-70 mm OS @ 70 mm
Construction and autofocus
As we are used to of Sigma, the zoom ring turns without play and with just the right friction. The focus ring has a very short stroke and runs very lightly. On the lens, it says “Macro.” The subject has then a size of about 5 to 7.5 cm, but is located a few centimeters from the front lens. That does not work conveniently in practice, because of shadowing. The drive of the auto focus is done with an HSM drive. Focusing is very fast and nearly silent with a Canon 600D; from 15 meters to 1.5 meters in just 0.18 seconds. Even in low light, the AF is accurate.{insertgrid = 289}
Image stabilization
The effectiveness of the built-in image stabilization is measured at a focal length of 70 mm. The effectiveness is about 3 stops.
Vignetting
The vignetting expressed in stops is just too high at f/2.8 and f/4.0. It is remarkable that this does not apply to a focal length of 28 mm while it does for the other focal lengths. Vignetting can be controlled well with some programs.
Distortion
The distortion, expressed as a percentage, is high at all measured focal lengths except for 28 mm. Distortion can be controlled with software.
Flare
The Sigma 17-70 mm is sensitive to both flare and ghosting in strong backlight. In practice, you should take this into account.
Resolution
The resolution, expressed in LW/PH, reaches high to very high values in the center. At a focal length of 17 mm, the difference with the angles is large. At the other focal lengths, the resolution is also remarkably well in the corners. The resolution of the Sigma is higher at all focal lengths except outer wide angle than the resolution of the Canon 17-85 mm 4-5.6 and the Canon 15-85 mm 3.5-5.6. The Sigma is also a bit more luminous.
Chromatic aberration
The chromatic aberration is high at 17 mm and at the other focal lengths remarkably low. Chromatic aberration can be controlled with the right software.
Conclusion Sigma 17-70 mm 2.8-4.0 DC Macro OS review
Pros
- Very good resolution in the center at all focal lengths for a lens in this class
- Good to very good resolution in the corners, except for 17 mm
- Practical zoom range
- Very fast autofocus
- Solid touch
- Good price to quality ratio
Cons
- Very poor sharpness at 17 mm in the corners
- High distortion at 17 mm
- Sensitive to backlight
- Chromatic aberration at 17 mm on the high side
The Sigma 17-70 mm 2.8-4.0 DC Macro OS HSM has a much more interesting zoom range than the Canon 18-55 mm kit lens. Those extra millimeters on the telephoto side allows this lens to work as a portrait lens. The resolution is, except for the wide angle, higher than the resolution of the Canon 17-85 mm 4-5.6 and the Canon 15-85 3.5-5.6 mm. The performances in terms of distortion, susceptibility to ghosting and vignetting are very average but the lens is more luminous than its competitors. Despite the slightly higher purchase price, the Sigma 17-70 mm OS offers value for its money because of the high resolution.
