I put the lengthy TC300 2x converter on the 300 4.5 ED-IF,tripod mounted it, and took three frames at a fairly slow speed (1/125th at f/5.6) or 1/125 at f/11 equivalent. I am near the minimum focusing distance here. When the actual focal length is 300mm x 2, it's nice to have a precise manual focusing system, and this lens really does have a GOOD manual focusing action. In its day, this was a very nice lens,and its mechanical design makes it a nice lens in actual use. Performance with the TC300 Nikon converter is quite good, although the image does dim considerably when that 2x convertr is affixed.