User Activity

 I have noticed that when camera focal length shows 4mm, I always get rounded corners. Is there anything I can do to avoid it.
I am trying to learn to use Av mode and experiment with various settings. One thing I have noticed is on Av mode, camera always increases ISO value. Same shot taken in automatic mode and Av mode get ISO value of 200 and 600 respectively. Is there any...
While checking the ISO settings, I came across the menu entry called Rate of change. What does rate of change do? I could not find any explanation in the manaul