Sigma 17-70mm f2.8-4 DC Macro OS HSM


I took this lens with me two days ago when I went to a trip with my friends. I took some really nice photos with this lens.

(All photos below are straight out from camera, only minor brightness and contrast adjustment have been done)

Beautiful colours


Good bokeh. With aperture of f2.8–4 this lens will produce a nice Out of Focus background and/or foreground to bring subject into attention.


Good sharpness (at least sharper than kit lens)


Good Macro (close up), I took this photos with lens zoom all the way to 70mm, f4.5. The distance of the end of the lens to object is no more than 10cm.



Good 17-70mm zoom range makes this lens a good all rounder lens to use. I planned to shot only a couple of photos with this lens but found myself shooting with this lens longer than planned.

Cons: The only problem is the focusing. Often I find the lens struggle to lock into focus with low contrast objects or in low light situation. Maybe I got a bad copy. But surprisingly it focuses good when taking macro photos.
It would be nice too if it has constant f2.8 aperture.

Pros and Cons aside, this lens is capable of producing nice photos. All the photos above are JPEG files straight out from my 40D.

Specification
Diaphragm blades: 7 (rounded diaphragm)
Minimum focus distance 0.22m (8.66”)
Internal focus, front ring doesn’t rotate when focusing.
Metal mount, weight 520g
Comes with hood.
Filter thread 72mm