I'd like to trade my 300mm for a decent flash/ambient meter or maybe a small studio strobe. When I bought this lens, the aperture blades were showing a little oil on them and was sticking. I sent the lens to Focal Point for a cla, and they did an excellent job. The glass is mark free, no fungus and maybe a few specks of dust inside if any. Hard to tell. I've got the receipt from the cla. I find I don't shoot long, mainly wide to up to 105mm. Let me know if you are interested. Thanks