Since no one will buy my 90mm I have been playing with it on the G1 and the OUFRO extender. Does anyone know the the formula to calculate minimum focus distance for this? I plan to do some macro work. The bokeh is wonderful with this set up and easy to focus, though I can see where a tripod will be necessary. This was handheld, 800 ISO, f/2. The background is a textured wall. But is very smooth with this set up. About 8 inches away from the magazine. Focus was on the word The. Not sure I sized it right. I am not experienced in web photo posting. Frank