I just got my new 70-200 2.8 (non is) in the mail today. I got it used on ebay but it was only used for a month and not that fruequently. When i got it i was so excited. This is my dream lens. I shot a lacrosse game with it. It is fantastic. It came with a filter the manual warranty and case for a great deal. I like it but how should i be sure there are no problems with it that i dont notice right away??? like how do i know it is being used to its full potential and how do i know its focusing right etc. One question was that i was shooting and it jumped off focus and back into focus real quick with a kinds thump noise like the IS version does when IS is enabled. Is this ok. I was also shooting on normal AI focusing so maybe it could track it well enough.
Thanks