Hi, I struggle to understand what's so good about flash and TTL, particularly on my M6. From what I understand, TTL tell the flash how much light to burst depending on the amount of light measured by the metering system. Am I correct? But then, what about distance? If the metering reads the subject is mildly lit, it'll tell the flash to burst a mild amount of light, right? But what happens if the subject is really far? The burst of light will not lit the subject enough, right? Does the M6 (and other camera TTL systems) take into account the focusing distance?