Minolta 28-85 3.5-4.5, KM 18-70 3.5-5.6.
Decent price, F/2.8, useful focal length range, flower hood, internal focus, quick and precise AF.
72mm filters, chintzy focusing ring, F/2.8 only at 28mm, strange flash behavior.
I picked up this SIgma on closeout at a local camera shop and it’s a decent sample.
The lens has a plastic build, rubber zoom ring, plastic focusing ring, and metal lens mount. it feels solid mounted on the 5D. The zoom ring moves well with no hitches, and there is no zoom creep. The focusing ring is another story. It lacks the nice rubber ring of the zoom ring, and though it is ribbed for good feel, it would be much better with some rubber. The ring is a little clicky too, but nothing out of the ordinary for mechanical coupled lenses. The bayonet mount flower hood is easy to use and doesn’t interfere with filters. The 72mm filter threads mean expensive filters but you can use polarizers very easily.
The autofocus is surprisingly quick and accurate for a lens of this class. Quieter than the Minolta 28-85 original by far.
Focuses down to about two feet, but no macro capability.
The lens takes acceptable pictures of decent sharpness and color quality. The DOF is incredibly shallow at f/2.8 and the images do not have the best of sharpness. The lens hood does a good job at controlling flare, but this version of the lens lacks the new digital coatings and I’m not sure how much of a difference it makes as far as flare goes. Stopped down, like most lenses, its sharpness is very good. Distortion is another story and is the achilles heel of the lens. 28mm has edge distortion, but not as bad as the 28-85 Minolta. Still, shooting a golf green at 28mm shows a curved pin – not too fun!
Color and contrast seem decent enough. I also haven’t really noticed much chromatic aberration. There is some at the tele end, but it’s not as bad as the kit lens. That’s really the story of this lens – it’s an acceptable performer. It doesn’t really excel except perhaps at offering f/2.8 at a nice price.
One last word, though – I’m not sure if this is the 5D or the lens, but I’m banking on the latter. When you use it with the flash, its behavior with selecting apertures in either program or shutter priority is kind of borked. Using P or auto mode, it will default to F16. Using S mode, it will always use the widest aperture regardless. This yields some… interesting results with the on-board flash. WIth the 3600HS, the F/16 setting actually produces pleasingly exposed images in close quarters. It may just be the chip on my lens, and Sigma service might fix it. But so far I will use only aperture priority when using the flash.