And now, completely inside the brick silo, shooting straight up the stair support pole, we’ve got even less available light! At 18mm ISO 800, at f6.3 (for more depth of field), our shutter speed was ⅓ second–much slower than the handholding rule allows without OS, and we’ve got a sharp frame, showing just some subject movement as another lighthouse climber descends the stairs. Without OS, this frame would’ve been a blurry mess!