I recently acquired an EM5II with 12-40 f2.8 Pro. I noticed the bottom corners, especially the bottom right corner, is not as sharp as the other corners. Granted this is at 35 - 40mm @ f2.8. I've always heard people rave about this lens so just wondering if that may be within normal tolerances for this lens? Please see these examples below. Shot on tripod with IS off.