I own a D7200 and am still learning how to use all of its features. I just noticed the camera is consistently choosing high ISO (3200-6400) indoors under low light conditions even when the built-in flash is ON. I observed this behavior in both A and M modes with auto-iso. If the flash is OFF, camera would chose more or less that same ISO, but that is understandable. But I couldn't really understand why it is still using same ISO with flash.
When I set ISO manually to 100-200 with flash ON, I am getting very decent results with no noise. The default behavior of camera of choosing high ISO is generally producing similar overall looking images but with very high noise (because of the high ISO).
Is there a way to set camera properly to choose lower ISO when flash is ON?