undercoverbrother
Senior Member
ISO is part of your exposure triangle so you need to set A, S and ISO in a correct combination when shooting. If the shot is too dark, you can up ISO, open the lens or lower the shutter.
To add: to make things a bit easier, there's an exposure indicator you see in the viewfinder or on the top LCD. If it is filled to the left, the shot is underexposed, if it starts filling to the right, it is overexposing. It'll differ depending metering.
not sure if these help, OP sorry if these are irrelevant to your post. let me know and i will make my own thread. I just saw a link between the two which may help out others.