Understanding Exposure Mode

A-DEP: Allows you to select your f/stop. It uses the distance between the object and camera so the whole picture is sharp. It selects your shutter speed for you according to the aperture you picked.

Av: Allows you to choose your aperture, the camera selects the shutter speed according to you aperture choice

M: Allows you to You basically get control over all the features including the aperture and shutter speed 

P: Allows you to choose from a combo of already set shutter speeds and apertures.

TV: Allows you to select the shutter speed of your choosing and selects the aperture for you.

A DEP 1/40 4.5

Av 1/20 8.0

M 1/30 5.6

P 1/30 4.5

Tv 1/5 14