Summary: I've owned the Tamron 200-500mm telephoto lens since 2010 and have used it several times at a zoo or landscape shots. Last night I used it for my grandson's baseball game on my Nikon D800 and was very impressed with how fast it focused which I thought was as fast, if not faster, than the Nikon 80-200mm which I usually use for his games.
Summary: At first i was disappointed that focus was more soft than expected at the extremes of zoom (200to 230. And 475-500) HOWEVER.. Between 240mm and 470mm of zoom it is one the finest pieces of glass in my lens stable! And it performs extremely well throughout that range in conjunction with a Tamron 1.4 teleconverter as well! Also, its performance with a 2x converter is very good between 2250mm and 425mm. It is absolutely an indispensible part of my regularly used kit!
Summary: I knew this when I bought it. I use it for getting the shot of dogs running Lure Coursing which is an outside event. I have several Tamron lens. I love the old ones best they seem more compatable with Canon bodies I have. Also they seem clearer and better lens in general. Not as happy with the newer ones.
Summary: Good response when focusing, needs plenty of light, you will need a tripod to use in wildlife. I am not super happy with it but I can't afford the Nikon product. The Tamron does the job, I am not happy since I do wildlife photography and not good when birds are in motion.
Excerpt: Strong lens, I have just received this lens and have used it twice for my son's football game. Best results are at F8 , and between 300 and 400 mm. I used this lens from the press box and was able to get excellent action shots.
Summary: This lens is worth what they ask for it. That is, it does not compare with the sharpness one would expect from a brand Nikon lens but the picture quality is fair. Don't expect too much bokeh or low-light capabilities. For shooting outdoors at reasonable speeds, this is a great lens.
Excerpt: I live in an area of southwestern Iowa which is rich in wildlife. There are several pair of nesting eagles that I am frequently able to photograph. Along with a wide variety of other wildlife to photograph.
Pros: Durable, Easily Interchangeable, Fast / accurate auto-focus, Rugged, Strong Construction