ISO: Film Speed

Picture #1: ISO 5000

Picture #2: ISO 400

Picture #3: ISO 50

Picture #4: Flash (auto iso)

ISO is the film speed, how fast the camera gives out light. The Higher the ISO then faster the camera gives out light. So in picture #1 the ISO is 5000, that means the light came out very quickly. In picture #3 the ISO is 50 so it told the camera to let out the light slower, thats why its so dark. When you have ISO the majority of the time the photo may look alittle better when compared to a flash. A flash in the dark it just makes the emphasis very very bright white color and makes your background dark. It just depends on whats kind of effect you are going for, I prefer using the ISO compared to the flash it makes you picures visibly more attractive. When using a fast ISO you need to make sure that you photos dont have that snowy, grainy, pixilated effecft. Unless thats what you are looking for:)