I just ran I just ran the cross of dumb mistake in wanted to share it here possibly help others to avoid it . My go-to digital camera is a NikonD800 and I usually have it set toP or(program mode), which I kiddingly call professional mode. When in this mode I typically have the auto ISO feature turned on and limited to ISO 3200 to give it more flexibility. This has now caused a problem. When I go back into the studio I don't rely on the camera's meter but use the flash meter instead, going back to manual mode visit the shutter speed two 1/60s us M and the f-stop to whatever the meter told me. In this case I didn't realize that's the auto ISO feature cranks the sensitivity all the way up to numerals ISO3200 because of the dim conditions in the studio and the images are totally overexposed. raising the f-stop or lowering the flash power did not help. The only way to get to a proper exposure is to manually set the ISO to the same value that is set on the meter. So, the auto ISO setting on the camera can be a problem. It took me a while to wrap my brain around that one so maybe my experience will help you to avoid this mistake.