QUOTE(darthbaboon @ May 16 2008, 09:54 AM)
Did you just step out of an air conditioned room? If so, that anomaly would be called "condensation" on your lens

This happened a lot to me when I bring my camera out of air conditioned room to outside. It gives quite a nice blur effect sometimes

. Another question, will the condensation cause any harm to the camera and lens? How to prevent it? One example picture