This is the first time I've gotten to the zoo with my new zoom for the Pentax. I was pleased with the performance of the lens. Most of the shots were at the widest aperture, with some as low as 1/100. The length and weight of the lens makes it a bit hard to manage, though I think the heft of the thing actually does help to steady the camera at low speeds. I'll need some more practice at coordinating zoom and focus functions, and some kind of brace would be nice.