The lens arrived today and when I got home from work I unboxed it. The descriptions most have posted about the lens are accurate if not underrated. I pulled out the 12-60mm f/2.8-3.5 and did a quick comparison look. The first that hit me is the 12-60 is only little larger, not the significant difference I expected. And the 12-40 is about the same size as the 12-50mm, only a little larger diameter. I was in a room where the exposure was ISO 200, 1.3 sec, f/2.8 so the EV would be just a little under EV3. This setup focuses quick and accurately on anything I pointed the camera at! Without a doubt in the realm in the realm of today's top pro cameras. As it was already dark outside I thought I'd check the S-AF close focusing ability. I mounted the 12-40 and my just repaired FL-600R flash on the EM-1. And snapped a couple of shots after trying to make sure I was as close as the lens could automatically focus. The target, a nickel on some black leather. The American nickel is .835 inches in diameter (21.2mm or just a little larger than 13/16"). EM-1 set to muted picture mode, Auto WB, ISO 800, 1/20, f/2.8, 12-40mm f/2.8 lens at 40mm, flash bounced, imported into Lightroom 5.2 using all default settings, no adjustments made except Lightooms sharpen at export for screens. The first photo was originally 4306 x 3456 resized to 1,000 x 750 for the web. The second is a crop of 997 x 748 without any resizing.