Samsung UN46ES6500G E-Manual page 199

Light
for PDP TV
is set to On, you can manually adjust
the minimum screen brightness.
N
If the
display brightness may change
(become slightly darker or brighter)
depending on the light intensity
in your room. You can control the
screen's minimum brightness with
the Min. Backlight
function.
: When the
Eco Sensor
Eco Sensor
is set to On, the
/ Min Cell Light