Manual Camera Settings

This is an under-exposed picture, I used 400 for the IS. The shutter speed I used for this picture was 1/60. 

These two pictures are correct as it's not 
under-exposed or over-exposed. I used 800 
ISO and the shutter speed was 1/25.










This picture is over-exposed as the ISO was 400. The shutter speed that I used was 50.