If Auto Light is enabled, display illumination will turn on automatically whenever the watch is positioned at an angle of 40 degrees or more when it is dark.
Important!
Auto Light may not operate properly when the watch is at a horizontal angle of 15 degrees or greater from horizontal as shown in the illustration below.
Auto Light may operate unintentionally and run down the battery if the watch is blocked from light by your sleeve.
Electro-static charge or magnetism can interfere with proper auto light operation. If this happens, try lowering your arm and then angle it towards your face again.
When moving the watch you may note a slight rattling sound. This is due to operation of the auto light switch, which determines the current orientation of the watch. It does not indicate malfunction.
Note
Auto Light is disabled when any one of the conditions below exists.
Alarm, timer alert, or other beeper sounding