Light Check uses the light sensor on your phone to read the light level. It can be used to read the brightness of any computer monitor or TV as well as the light output of any light fixture.
To read the output of a light fixture in Lumens hold your phone one meter from the light with the screen facing the light. The Lux reading will give you the lumens.
By laying it on the screen of your TV or monitor over a pure white area it will give you the the light output of your monitor. Very useful when your display needs to be accurate for photographers, designers, editors, or fans of accurate images.
To measure your monitor put up a white field. Start Light check and press Reset. lay your phone on the screen with the light sensor on the white. Pull the phone away and read the Max reading. That should be your monitor's reading. This will work best if the lights in the room are dimmer than the monitor.
The accuracy of the readings will vary depending on the accuracy of your phone's sensor.