rook2c4 wrote:
The EXIF data indicates that you used spot metering. Apparently, you spot metered off the darkest spot in the scene (the very center of the flower), and the camera adjusted exposure accordingly. Spot metering for this is okay, but make sure you choose the spot wisely. Near the edge of the flower, for example.
Even before reading this post, I knew the OP used spot metering. It only makes sence that would happen. Otherwise changing in post could do it.