Sigma 180mm F3.5 EX IF HSM Macro Lens for Pentax-AF Camera

Rating:
Summary: Not great
Review: I feel that this lens seems a lot slower then my others. Since this is not a lens that I must use since I have a better lens at the same focal length I rarely use it. I don't recommend it but others might like it.

Rating:
Summary: Sigma 180mm/3.5HSM (Nikon)
Review: I shoot nature semi-professionally, and use a lot of pro Nikkor glass. This lens is among the highest in optical quality that I have worked with. The images remain sharp and contrasty at all apertures (remember that DOF is very shallow at 3.5 and 4), and the bokeh is very nice opened up. The color may have a slight warmness compared to Nikkor's 60mm/2.8. I have been banging this lens around in the field for a month or so; the build quality seems excellent, and the tripod mount is nicely balanced. Focusing is silent, fairly fast, and very accurate on F5, N90s, and N80. The manual focus (primary mode in macro photog.) is nicely dampened for an AF lens. I am shooting transparency film on a tripod with a cable and focusing stage.
All in all this is a fine optic and it is priced reasonably.

Rating:
Summary: Better choices are available.
Review: Unless you need the extra distance afforded by the 180mm focal length of this lens (i.e. you want to work father away from your subject), your money would be much better spent on Canon's 100mm f2.8 USM macro lens. Canon's 100mm macro is also capable of 1:1 reproduction and offers better optics and build quality. More importantly, Canon's lens costs less than this Sigma lens. Save your pennies and work with a shorter focal length -- you won't regret it. This lens, while capable relative to the rest of Sigma's products, is not in danger of producing really impressive results.