Hiya
I have found out that there is a optimum ISO for each camera out there. Now being a newbie to photography I would have thought that iso 100 would be the optimum for all cameras but apparently not. From what very little I know each make and model has a optimum iso that is not necessarily iso 100, its called a "native" iso. Can anyone explain this and how would I know what mine would be for a canon 550d??? Thanks!!!!