SX50 bird fiasco. Help.

BobT wrote:

The window glass could cause some of the problem, yet I have captured razor sharp images in the past thru that very same window. Now, the size of the AF box seems like something of more importance to me. But I can't seem to reduce it's size. The color of the box goes from white to yellow(what's the difference there?), but no size change. What am I not doing?