Make the iPhone Screen Dim

As of iOS 5 there is a public API in the UIScreen class. It has a brightness property that can be set. For those instances where you may want to go dimmer than the actual backlight allows, there is a wantsSoftwareDimming property that will automatically place a translucent layer that will give the appearance of being more dim than can be done in hardware. This is very similar to the method you came up with with the translucent UIView. It should be noted that using your solution or the software dimming API should not be used with many animations since you will pay a performance penalty with all the alpha blending.

See UIScreen Class Reference

Dim iPhone Screen, but don't let it sleep

I'm pretty sure there's nothing in the official SDK.

[(id)[UIApplication sharedApplication] setBacklightLevel:0.3f]; // or whatever value

works, but is of course undocumented. The recent experience with UIGetScreenImage indicates that perhaps the right strategy with useful but undocumented APIs is to use them and see what happens.

Failing that, has anybody ever measured if the phone's power consumption goes down if it's showing a black image, or does it not help unless you can turn down the backlight?

How do I prevent the iPhone screen from dimming or turning off while my application is running?

Objective-C

[[UIApplication sharedApplication] setIdleTimerDisabled:YES];

Swift

UIApplication.shared.isIdleTimerDisabled = true

How can I dim the view in an iPhone application?

Ok, the way I did this was too create another view and set the opacity very low. Then I add this view as a subview.

How to call the UI for screen brightness

Have you tested [[UIScreen mainScreen] setBrightness:0.1]; for values from 0.0 to 1.0 over a noticeable time span? Does the brightness change? Do you get the UI?

Adjust the main screen brightness using Swift

https://developer.apple.com/documentation/uikit/uiscreen/1617830-brightness

From the docs the proper answer for Swift 3+ is:

UIScreen.main.brightness = CGFloat(0.5)

Device brightness with video on screen affecting white color

After communicating with Apple support, we discovered that the video_full_range_flag was not being set by ffmpeg. Re-encoding the videos using the following ffmpeg command worked: ffmpeg -i input.mp4 -map 0 -c copy -bsf:v h264_metadata=video_full_range_flag=1 output.mp4.

Make the iPhone Screen Dim