The current torch brightness level.
- iOS 5.0+
The value of this property is a floating-point number whose value is in the range 0.0 to 1.0. A torch level of 0.0 indicates that the torch is off. A torch level of 1.0 represents the theoretical maximum value, although the actual maximum value may be lower if the device is currently overheated.
You can observe changes to the value of this property using Key-value observing.