Does the Grayscale Feature in iOS 8 Extend Battery Life?
The grayscale feature in iOS 8 can have a minor impact on battery life, but it's not a guaranteed way to significantly extend it. The primary benefit of using grayscale is to reduce distractions and potentially decrease screen brightness, which can save battery life. However, the actual improvement in battery performance varies based on how you use your device and other settings.
Understanding the Impact on Battery Life
In general, the biggest factors affecting battery life are screen brightness, background app activity, and overall usage patterns. If you want to maximize battery life, consider lowering screen brightness, closing unused apps, and managing location services in addition to using grayscale.
Why Grayscale Might Not Save Battery Life in iOS 8
Unless Apple decides to switch to AMOLED, there is no power saving using the grayscale feature on iOS because iPhone/iPad are using LCD screens. Enabling grayscale mode will not significantly impact power savings on iOS devices with LCD displays, such as the iPhone 6 and later models.
I haven't read anything stating that you would get better battery life by using grayscale mode. As described in other answers, the screen is still having to use all three colors to make gray tones. This means that the backlight is still active, and the process does not lead to substantial power savings.
Technical Explanation: LCD vs. OLED
The reason behind this is as follows: In OLED-based screens, simplistically speaking, each individual pixel provides its own lighting. In contrast, LED/LCD-based screens have a screen-wide backlight that illuminates or shines light through all the pixels at once.
OLED is like having light switches in each room of your house, whereas LED/LCD is like having one master switch for all lights in your house, regardless of whether the room is being used or not. As a result, on OLED-based screens, blacks mean the pixel is off, and no power is consumed by that pixel. However, on LED/LCD-based screens, black pixels still mean the backlight is on to illuminate all other pixels, leading to minimal power savings.
Conclusion
While the grayscale feature in iOS 8 can offer some minor benefits by reducing visual distractions and potentially lowering screen brightness, it is not a guaranteed way to significantly extend your device's battery life due to the underlying technology of the LCD screen. For maximum battery savings, focus on other strategies such as lowering screen brightness, managing background app activity, and optimizing usage patterns.
It's important to note that future iPhones could potentially sport AMOLED displays, at which point grayscale mode might offer more significant power savings. However, for now, grayscale mode remains more of an accessibility feature than a power-saving tool.