Another New Lens!
Picked up another new lens today, a used Sigma 24-70mm, f2.8. While this lens is significantly cheaper than my Canon 17-85mm IS/USM, I think it was a good purchase. It provides an f2.8 aperture over the entire range of the zoom, it has a very wide and smooth manual focus ring, and its large diameter (82mm at the front) makes it easy to grip firmly for stabilization. On the downside, it is heavy (over 700g), and the focus servos are extremely loud. But really, this lens just begs to be manually focused all the time. Besides, my camera makes it a point to let me know when it's in focus.

In reading some reviews, I can see that reviewers mention the same points I raised, but the verdict is also that the optical qualities of this unit are great. Some say it's comparable to an equivalent Canon L-series lens. I'm a little skeptical about that, but I'm happy to read that the corners stay bright and sharp.

I first tried this lens at a bowling alley lit only by blacklight. I was very impressed by how much light it took in, with the range of tone and colour. As someone who avoids flash at all costs, I'm glad to own this lens now.