Android App: Low Light


Low Light is an Android application available at the Amazon's Appstore. The program comes with nine preset levels selected to match human perception. They are sufficient for most cases. For finer precision, you can use the slider which is also designed to produce perceptually even changes. The preset buttons are also the markers on the slider scale: if you tap on the slider between the buttons 64 and 128, you will get the brightness of 96. With this design the desired brightness is always one tap away. There is no need to program the presets and no need to remember what values were there.
With Low Light, you can schedule brightness changes at two times of day. For example, schedule full brightness in the morning and low brightness in the evening. The app can also set the desired brightness after the device was in sleep mode for the specified time or more.

"Start At Boot" option allows to keep Low Light running and your scheduled events active.
No root is required.

Low Light Demo is available at the Appstore. It provides the same functionality as the full version but expires after one week.

The Basics

Please be very careful with low (1-32) brightness settings: the screen can become unreadable in bright light. If this happens, take your device into dark environment or reset it by holding the power button.

Using Low Light is as easy as using the system's brightness control. When the app is running, tap on the left corner of the top bar. When the drop-down list appears, tap "Low Light" - this brings up the main window. Tap a brightness button, then tap anywhere outside of the Low Light window and you are back where you started but with the new brightness applied.

To close the main window you can also use the back button (left arrow) on the bottom bar or the blue application icon on the left.

In some cases the top bar is not visible. If there is a small up arrow in the middle of the thin bottom bar - tap on it, and both top and bottom bars will appear. In Kindle Fire Reader just tap in the middle of the screen to bring up the bars.

The application integrates seamlessly with the system's brightness control: you can use it as before. But obviously you still have to use Low Light to get to the low settings.

Note the Settings button in the right corner. Use it to configure the options, to go to the help screen or to quit the application.


There are three types of events which can be used to set the brightness:

1. Wake-up Event.

On wake up from sleep the application checks time spent in the sleep mode, and if this time is longer than the time set by the user (and if the option is enabled), brightness is set to the specified level. This is useful when you leave your device at low brightness in the evening: after it sleeps for the preset time or more, it will be at full brightness in the morning. If you set the time to 00:00,  brightness will be set every time the device wakes-up.

2. Time of Day Events

One can also schedule brightness changes at two preset times. Your device can be set to full brightness in the morning, and in the evening it can be set to a low level comfortable for night reading. Scheduled brightness changes can happen while the device is active or in the sleep mode. When the brightness is changed by Low Light, a short notification informing of the change is displayed.

How these events work together:

in short - at any given moment you see the result of the latest brightness setting event (of course if you did not change the brightness since then manually). Time of day events happen at the preset times and the wake-up event happens when the screen is turned on. For example: brightness was scheduled to be set to 128 at 5PM, the device was sleeping at 5PM, wake-up event was configured to set brightness to 255, the wake-up happened at 6PM. Then the resulting brightness is 255. Obviously if the the setting at wake-up was disabled, you would see brightness of 128.  

3. Boot time

"Start At Boot" option allows to keep Low Light running and your scheduled events active. After the reboot brightness is always set to the maximum. This option can be useful as a recovery in the case the brightness is too low and the device needs to be restarted. Please note that reboot follows complete powering-off of the device, not just putting it to sleep by short press on the power button.

Quit button stops the application and cancels all scheduled events.

General Info

Low Light design takes into account human perception of brightness. It is a very complicated subject which is still being studied these days, but its major feature is that humans are sensitive to relative, not to absolute changes of brightness. For example the change of brightness from 1 to 2 is perceived as strong as the change from 128 to 255. Here we assume that the changes happened in two different lighting environments in which the settings of 1 and 128 were most comfortable. The brightness units are determined by the device hardware.

This feature is used in the selection of presets: they cover the whole range evenly in terms of human perception. The neighboring presets differ by a factor of 2. Since the full range of brightness provided by the hardware is 255, we have total of 9 presets. We find that these presets are completely sufficient, and smaller brightness steps are not really necessary. Nevertheless if you ever want a finer precision you can always use the brightness slider. It is also designed to produce even changes across the whole range. The preset buttons are also the markers on the slider scale. For example: if you tap on the slider between the buttons 64 and 128, you will get the brightness of 96. With this design the desired brightness is always one tap away. No need to program the presets, no need to remember what values were there.

Another feature of brightness perception is that it is subject to adaptation. This is quite evident when you come from bright sunshine to a dark room. You will progress from being almost blind to being able to see things around quite well. Because of light adaptation there is no such thing as "the preset" for night reading. Your most comfortable setting will change as you get adapted to the current setting. More than that: the optimum depends on the content you are looking at. White text on black background and black text on white background would require different settings. Also for video you would like to use higher brightness than for reading.

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  • Full range of screen brightness settings, can set values lower than the system's brightness control

  • 9 brightness presets selected to match human perception

  • Brightness slider is optimized to produce even changes across the entire range

  • Runs in a small panel allowing to see most of the screen behind it

  • Provides fast access to settings via status bar notifications window

  • Can set brightness at 2 scheduled times

  • Can set brightness on the device wake-up