Just clarifying how his works. By default exposure is automatic, but if you tap the 'sliders' icon for settings the options pop out from the left. You can then change shutter by turning RH side dial. If you press in the dial the adjustment changes to ISO. You can see which is 'live' because it shows blue. Now the less obvious bit: if you tap settings again the options panel goes away but it's back in auto. If you want to stay manual so as to be able to adjust again if need be - without the panel visible - just drag it to the left and it stays in manual. When not in manual mode the wheel acts on exposure but not necessarily in the best way depending on conditions and what you want to do. It will soon bump the ISO much higher than you might choose for example.