I have a Nikon 5100 and the option to change the ISO settings on Auto mode isn't available. The option is grayed out and it's stuck on auto. The ability to change ISO setting is only available when your in P, S, A or M mode. Does anyone know how to change it so that I have ISO control in auto mode as well?
There is no way to change the cameras ISO when you are on the preset Auto mode. This is typical of all cameras. This is because by being in Auto you are telling the camera that you want it to control all the settings. Hence the greyed out ISO control.
You can try changing the camera mode to P (Program) which is still an auto mode; but it gives you slightly more control over your settings. E.g. Changing your ISO.