60%, auto=on. With auto=off the brightness goes way up. So the folks with the brightness at 50 or less probably have auto=off.
I concur with Zetaprine that the iPad 3's screen brightness goes way up when you turn OFF auto-brightness.
With "auto brightness" turned ON, i need to set my iPad 3 at 60-65% brightness.
With "auto brightness" turned OFF, I need to lower the brightness down to 45-50% in order to match the prior "auto brightness" ON setting.
That said, which auto brightness selection better preserves battery power:
setting "auto brightness" to 'on' or 'off'?