what causes the blur on the ring
is it normal?
can it be prevented?
Answer sorry, again, I can't tell. and why is there a pizza hand in the picture...
But my guess is that the camera is not focused on the ring. You can prevent this by focusing the camera on the ring. Pretty easy with an digital SLR, not so much with your basic square camera, but it can be done, you just have to play with it.
You can take the photo into photoshop and use the sharpen tool in it, but don't do it too much.
)