>>3576061think of it like a wooden door on hinges, an ordinary door
you must think that, regardless of shutter speed, both doors start fully open to the same degree, this is false.
a low shutter speed has a very wide open door
a high sutter speed has a more narrow open door, more akin to an ajar door.
it requires more light because the gap of an ajar door lets in less light than a wide open door.
