ISO

ISO Flash

ISO 50

ISO 400

ISO 5000

Iso is the film speed. Iso is how fast the light gets in your pictures. The difference between these couple of pictures is the lighting in them. With an ISO low it is dark and sort of blurry but then when I put the iso higher the picture kept getting more light in them. I would chose ISO over flash because with a flash your subject can be disturb with the flash and with ISO your subject can stand and not blink because of the flash. You would have to be careful with ISO because the picture may come out too blurry if you put it too high or too low.