ISO

FLASH
ISO 50

ISO 400

ISO 5000

The ISO is the film speed and the film speed is how fast the light comes in to the picture. The pictures that flash was not used came out gritty, but softer. The top picture is an average photo using flash, but the one under is a change in ISO to 50, then 400, then 5000, the higher the number the brighter and more blurry the picture becomes. At times changing the ISO would be better then using flash so that the true colors of the image are not drowned out. In the flash photo you hardly notice the Christmas lights, but in each other photo you can see the color of the Christmas lights and the subject, instead of having to choose one or the other. When using a fast ISO you must be careful with how blurry and gritty the picture may become.