Android and iPhone 4 auto-brightness virtually useless, claim researchers

Nobody thinks much about the auto-brightness feature on a smart phone. But you should do, as screen brightness is one of the main ways to run down the battery. Unfortunately for iPhone and Android users, a new report has come to light claiming the auto-brightness feature on these handsets is "close to functionally useless".

This is because smart phone manufacturers haven't made the effort to develop and test the relevant software and hardware properly, according to new research from DisplayMate, which recently tested the displays of several high-end smart phones.

The automatic-brightness feature on a smart phone works by using a sensor in the bezel next to the screen that measures the ambient light. Software is used to raise or lower the screen brightness depending on what the sensor reads. If you're using the smart phone in the dark, for example, the display should be dimmer.

DisplayMate tested the feature on the iPhone 4, HTC Desire and Samsung Galaxy S. It concluded that all the phones had serious operational errors and bugs when it came to the auto-brightness function. It even went as far as saying Apple, Samsung and HTC had made little effort to make them work.

"It's clear that most manufacturers are using ad hoc implementations instead of methodical science and engineering, which is shameful and shocking. As a result most smart phones are operating without auto-brightness because consumers disable them when they don't work properly," said the report.

This is a problem when it comes to battery life, as many people often set their smart phone to have perpetually high screen brightness. This means it runs down the battery of the phone much quicker than it should.

The iPhone 4 auto-brightness feature made the display too bright at lower ambient light levels, and too dim at higher outdoor levels. There is also a serious bug where the light sensor locks onto the brightest light source and sets the brightness of the screen to that value, continuing to display at that level until you switch the phone off.

The problem with the Galaxy S and Desire is that they only have four fixed automatic-brightness levels between pitch black and direct sunlight, rendering the feature effectively useless. They also have operational bugs that need fixing.

Considering the immense impact on the battery, do you think these manufacturers should put more focus on making sure the automatic-brightness feature actually works? How do you monitor the brightness of your phone to ensure you don't run down the battery too fast? Or do you even pay attention to this setting at all? Send us your tips.