I like to read in iBooks with the brightness turned down, but I have to re-adjust this every time I open the app. Is there a way to make my brightness setting "stick"?
On the off chance you weren't already aware, you can modify the system-wide brightness by double-tapping the home button and swiping the "shelf" to the left.
iBooks can set a lower brightness than the system will allow outside the application -- so if you frequently set it lower than the system's lowest setting, you'll have to make that change every time you open the app. As you can see in the screenshot below, when the iPad is at it's lowest system brightness, the iBooks brightness bar is at about 20%.
It is well documented that iBooks uses a non-documented, private API to modify brightness and you can clearly see some of the side effects of this since that setting does not stick and is confusing since it doesn't stick across sessions because it is not using the main settings but instead temporarily overriding them.
Only Apple can say whether this behavior is by design or a bug, but as a user you might want to officially send them some general feedback as they clearly felt it was a good enough to ship. You can also leave a review for iBooks in the App Store but that's generally less effective than a bug report or direct feedback about a problem. If enough people request a change, it stands a better chance of change in an upcoming releas.
I have been asking myself the same question for quite some time. Sadly I couldn't "fix" it.
The iPhone/Pad goes back to the brightness you have in the Settings every time, and in fact, the iBooks app, changes the brightness of the whole phone/pad, but as soon as it's "suspended" and "woken" it reverts back to the settings you had in the settings.
There is a way to actually make your entire screen go darker
- Go to settings > General > accessibility > zoom > toggle on
- Double tap with 3 fingers on the screen
- Hit the drop down bar at the bottom of the window
- Choose filter
- Low light
- Hit full screen zoom
- Double tap again
To make it as fast as sonic do these steps: Settings > General > Accessibility > Accessibility shortcuts > Zoom Triple tap home button for low light