The Lightning Mode uses the internal light sensor to detect lightning events. It has 3 parameters:
Sensitivity: This value determines the sensitivity level of your device for lightning. The higher the value you set, the more sensitive it will be. You can move the threshold bar by holding and moving circle with arrows or use "+" and "-" buttons.
You can see the light level of environment without starting the mode so you can adjust the sensitivity threshold according to light level bars. When a light event detected which exceeding the threshold value, it will be shown as "Orange" bar in this screen.
Trigger: This mode has 2 different options as "USB" and "ShutterPort". When you choose USB, your camera will be triggered through its USB communication port using the USB camera connection cable that comes with your Flex. If you choose this mode, your camera must be connected to your Flex over Camera Control Port.
If you see that lightning capturing is not fast as you expected through USB port triggering, you can also use remote triggering port of your camera. In this case you have to choose ShutterPort. So, your camera will be triggered through its remote triggering port using the shutter release cable which you buy separately. If you choose this mode, your camera must be connected to your Flex over Camera Trigger Port.
You can check the following page to purchase a shutter release cable.
Exposure: This value defines the exposure value for each photo. You can select the exposure value from exposure list or set a custom exposure (if your camera is in Bulb mode and your camera support Long Exposure function).
Once you set the parameters and press start button, a status screen will be opened as below.
You can stop the mode by touching Stop button 2 times. When you touch first time, the lock will be opened and when you touch it second time, mode will stop.