Coneflower.. halo?

[slh]

As you can see, there is a halo around some of the petals on the flower. Does anyone know what caused this? It almost looks like movement or camera shake but then wouldn't the whole flower be distorted? At a ss of 1/1000, I would think that any movement would be froze. It was a little breezy, shot under some tree's in slight shade. This is sooc, no pp at all.



Camera Sony DSLR-A230
Exposure 0.001 sec (1/1000)
Aperture f/1.2
Focal Length 50 mm
ISO Speed 100
Exposure Bias 0 EV
Flash Off, Did not fire

One other thing, I used a Pentax SMC 50mm f1.2 with an adapter for Sony. I haven't had this problem with other shots. Maybe should have set the lens at f2 or 2.8.

Steve