SET the ISO
ISO – refers to the brightness sensitivity of the camera, it’s a bit like gain. The
higher the ISO number the less light you need for correct exposure, the lower
the ISO the more light you need.
The standard setting for the Cannon 600D is 400 ISO. If you go to 800 ISO it
requires half as much light for the same exposure – so the equivalent of
adding 3db’s of gain. High ISO’s (like gain) will result in more nose and grain
and as a rule try not to set the ISO higher then 1600. The camera will go up to
6400 ISO, but this should only be used in extreme circumstances in very low
light. On sunny days set the ISO to 100.
ISO is set by pushing the ISO button and scrolling the adjacent thumb wheel –
the screen on the back of the camera will show you what the ISO is set too.
Don’t use ‘Auto’ ISO mode.