Excerpt: I have had the Sigma 50-500mm for a few years now and I am well pleased with the lens and the quality. The only thing that needs work is that the AF searches a good bit at times, it is worse in low light or really "cluttered" capture areas such as a bird in a thicket, etc.
Pros: Durable, Easily Interchangeable, Rugged, Strong Construction
Excerpt: I have used this lens for everything from nature to modeling shoots. It's very sharp and in AF-C mode is great for action shots. One drawback is the weight, the thing is built as solid as a brick. I like to shoot hand held and this makes for a long day holding this lens.
Pros: Consistent Output, Durable, Fast / accurate auto-focus, Nice Bokeh, Rugged, Strong Construction
Excerpt: Really gives the zoom needed to bring that far away item up close and personal.Rather heavy so will be a lot more to lug around. Wish there was some better way for more zoom without all the added weight.
Summary: This is an impressive lens at less than half the cost of the Nikon offering. I take a lot of cityscape photos and I'm several miles from the subject, yet when properly focused, this lens captures details of signs on the highway and the structures of the buildings are clear and crisp.
Summary: I have not been happy with the auto focus. I have used this lens with both a cannon T3 and a cannon 70D. The problem is it will no come into focus. I have contacted sigma asking if there is anything that can be done about this. I have not yet gotten a reply.