>>3269246It is the ambient light sensor. Both phones, face up on the same table in the same office.
It could be caused by anything, from differences in how the phone's protectors worked and then, subtle changes in how light scattered in the room.
The Camera's own meter was halfway between the both of them so I suppose it's in the realm of reasonable error.
One good thing about the old Spotmatics is that, for whatever reason, they're one of the few cameras of the era with proper voltage regulation in the metering circuit (It's a wheatstone bridge, IIRC) so it'll work merrily at modern voltages with Alkaline batteries,
