I just bought this lens used at a camera store tent sale for $75 for my Mark III. I wanted a zoom lens for my 8 year-old son's first season of football. I hope this works well for me. The only other lens I have to use is my 85mm prime, so I'm curious how much farther I can get with this. If the distance is negligible, then they said I could return it within 30 days. Does anyone have any experience with this for outdoor sports photography? I'm also curious if this lens is worth keeping in my camera bag even if it's not ideal for his football shots. Any insight anybody has to share about this lens would be appreciated! Thanks!