Summary: This lense is worth 3 times the price. I shoot in manual a lot and it gives clean,clear and sharp pictures.I would say it is my favorite lense. I rarely take it off. In low light you have to take your time. It is great for medium to bright light. At a full 300 it still stays sharp. Using auto focus will depend on your camara and how good it is but in manual it is amazing.
Summary: I like this lens. It has worked perfectly on my NIkon D40. The focus is quick and sure. I prefer to use a tripod. So, vibration reduction is not needed. My shots of birds are very sharp with this lens. I am very satisfied with the results.
Summary: The Sigma 70-300 is an exceptional lens. In general, the lens provides exceptionally sharp photos. More specifically, one of the features, that of providing macro focusing between 200-300 focal length range, is especially beneficial. My only previous experience with macro focusing has been with a lens that required being quite close to the object being photographed.
Summary: I was looking for a zoom lens that wasn't expensive since I'm not a professional but I do enjoy taking a lot of outdoor pictures and macro shots and when I saw this on Amazon, I was sold! I have an older Pentax K10D and this works great for my uses. Since most of my shooting takes place during the day, I have no issues with lighting since this lens does require good lighting to perform well.
Summary: It is really great for the price. It works with reasonably fast in Auto mode. The picture quality is very good. It was surprisingly produced good results as I was not expecting that quality from a low priced lens.