Heads Up folks!! I acquired this lens after all the good reviews, excellent photos, and internet hype. Well, be warned....this lens and ones like it, seem to have a technical flaw when used with a NEX or a6000. Can't tell you if full frame A7's will have this issue. I'm a bit surprised that Brian didn't have flare aberrations on his a6000. (Adapted Lens Showcase) My copy is the silver front focus barrel, black bodied, AUTO Mamiya/Sekor 55mm f/1.4. No A/M switch, and a silver aperture ring. M42. These are single-coated. And have a large flat rear element. The rear element seems to be reflecting bright light off the Sony sensor and casting a green flare onto the center of the photo. It does not move, it's fixed. Therefore not flare as we know it. As long as it's bright light conditions, the green blob is present. Stopped down to f11 or f16, it is quite focused. You can turn the focus ring until you see a perfectly focused hexagon from the iris blades! This is the first such experience with legacy lenses on my mirrorless body. I suspect other lenses with flat rear elements will potentially cause the same problem. I suspect the coating can not cope with a digital sensor. Film was darker and didn't have a glass aliasing filter in front of it either. A real shame....this lens is built wonderfully and the optical performance is superb.