I am planning to buy a Sigma 150-500mm lens. So before buying this I want to know about this lens..... I will be using it for bird photography.
Is it a good lens for medium range wild life photography?
1. Quality of photos with this lens?
2. Sharpness quality of this lens?
3. Auto focus quality of this lens?
4. I am using D90 body, so is it compatible with this?