How do I tell if the 100-400 meets a professional’s standards as a “sharp copy”? Are there some images (or a specific calibration target) I could shoot at fixed f/stops and fixed focal lengths, to make that determination? For example, if I mounted a newspaper page on a board and set it up on a stand, put the 40D/100-400 on a tripod at measured distances, is there some test you could devise that I could shoot in RAW, download into LR, export to ??, and send you given size images for a “sharpness” determination?