Is this a fixed 300mm lens, or what is referred to as a prime lens? I can't see anywhere in the specs and features where it shows a minimum focal length.
There is a switch on the lens that gives you two choices 6 meters to infinity or full range which is about 8 feet to infinity. I find in the full range the auto focus takes longer to focus.(it still fast) The only thing I shoot that close is a gray card for white balance and my color chart. My main use is high school football at night (very poor lighting condition, wide open, iso 3200 and shutter speed of 250 it gets the job done) and wild life. My 200-400 just not fast enough for the football games without getting lots of noise. Great lens that I have never regretted buying.