Tamron 200-400 Telephoto zoom was designed for the professionals. I bought it for around 400 dollars and loved it. I kept using it until I bought a Nikon VR lens 80-400mm. I sold the Nikon at one point and used this again. Then unfortunately it got some fungus inside and I wanted to open the top glass myself. In the process I damaged the top glass. But still all functions are perfect and autofocus works. I tried it as a soft focus portrait lens. It works but then again the use is limited. So I decided to sell it and some one can change the top glass and put it to perfect use. So bid accordingly. If you can change the glass and remove fungus, it can well match Nikon, Canon or Pentax in sharpness and overall quality.