Canon 70-200mm f/2.8L IS USM - $1800 http://www.bhphotovideo.com/c/product/544676-USA/Canon__70_200mm_f_2_8L_IS_USM.html Canon Telephoto EF 200mm f/2L IS USM - $4,800 http://www.bhphotovideo.com/c/product/542292-REG/Canon_2297B002_Telephoto_EF_200mm_f_2L.html#specifications I have been using a 7-300mm zoom. I have never shot with a fixed lens. What is your opinion on using a zoom versus a fixed? In this case, I assume the price difference is due to the difference between f/2.8 and f/2. However, I always hear photographers say you need 2.8. There isn't too much mention of using anything lower. Thanks.