I shoot a lot of macro images with flash and custom light mods. Most often I set my camera to F/18 and 1/200 of a second with 1/4 flash power.
Every time the light changes I need to adjust my ISO. I've tried AUTO ISO but since I'm focusing very close, the camera doesn't get the exposure metering right with my flash and light mod.
I wonder why the camera can't apply AUTO ISO after the image was taken such that the image get the right amount of brightness?