A little over a year ago while out in the Shenandoah National Park I came upon two black bears busy digging around a tree stump across a creek. Both bears were was so engrossed in their activities neither bear cared that a small group of photographers were shooting away from the other side. At that time I did not have with me any lens longer than a 105, but as I looked around, I saw almost every photographer with long Prime lens, 300, 400, 500 both Canons and Nikons shooters. Here I was with a great photo opt and I came home nothing to for my encounter. I was out that day with macro in mind, but thinking my longest lens was a 200mm anyway. This set in motion my desire to seek a longer lens something at least 300mm or longer.
There are a LOT of choices in the 300mm and longer range available and one could list half a page of various zooms that reach as far out as 500mm for under $1500.00. I have been down the lower budget zoom range before and in some situations they are fine for what they are but have draw backs in performance. As I began looking for a longer lens I laid my requirements out along with my maximum budget restraints; the resulting choices narrowed considerably. First I am not a professional who depends on photography for my income and secondly I was having a difficult time justifying almost 6K for a Nikon version of a 300mm prime. In the end I made my choice based on what I consider good quality at a more affordable price at near pro performance. After several days of reading, watching, waiting, stressing, My decision was to go for the new Sigma 120~300mm 2.8 Sport edition. Let me state had I the capital (cash) I would have went for the Nikon 500mm f4, and certainly one day I will have that lens.
Buy this wonderful lens: Buy a Sigma 120-300mm