Have the lens bought, I have no test charts but wintery bare trees with bare branches photographed so that, in each of the imprinted focal lengths. Loaded on the computer and there format-filling looked at on the monitor: from the center to the edge everything visible sharp. What more do you want. Have the images with the old-fashioned Olympus IB (like with better than the modern Olympus Viewer 3) reworked. With 50 units and 25 units more sharper contrast, any glare and any blurring is gone. Goes well with the Olympus Macro Converter. A whole photo equipment in a single objective: great! Greetings: Toivo