I have the older f1/4 EF that I use adapted to an M6. It's way soft under 2.2 or so and basically unusable for any non-flat objects under 30 feet at wide-open a

I have the older f1/4 EF that I use adapted to an M6. It's way soft under 2.2 or so and basically unusable for any non-flat objects under 30 feet at wide-open as the shallow DoF will blur a cheek if the nose is in focus. That said, it works magic at night.