Auto exposure mode assumes that the user trusts his device to adjust the brightness of the picture. But at the same time has some set of tools to slightly adjust the automatic result.
Automatic mode does not involve locking the shutter speed and ISO separately. These two parameters work in tandem. There are some devices where you can use “duct tape” to lock one of the parameters, but in this case, there is no need for that as the application is designed more for manual control.
1.5.1.1. Automatic exposure compensation controller
If the manufacturer of the device allows it, the automatic exposure can be corrected either to the plus or minus. The range depends on the device, but usually does not exceed ±2 stops.
Logically, increasing the value to the plus side, increases the exposure, makes the image brighter, and decreasing the value to the minus side, decreases the exposure, makes the image darker.
It's worth noting that automatic exposure can have a larger range of shutter speeds and ISO. This is one of the reasons why it's not easy to combine automatic mode with manual mode. We have no idea why the manufacturer does this and why they don't give the same range of settings for manual control.
1.5.1.2. Exposure mode button
Pressing this button switches the exposure mode to manual.
1.5.1.3. Automatic exposure lock button
The user has the ability to "freeze" the shutter speed and ISO value.
The locked exposure gives a more professional feel to the video.
On some devices, you may see a wrong response to locking the exposure. In particular, on Samsung Exynos devices you can observe a decrease in the brightness of the picture in the case of locking. This is a problem exclusively of a particular device.
1.5.1.4.. Automatic exposure information window
In this window you can see what values the automatic exposure control selects for shutter speed and ISO.
1.5.1.5. Fast access to expo-peaking buttons
There are two buttons for quick access to exposure control: zebra and false color. You cannot activate both exposure controls at the same time; each one disables the previous one.
Note that these buttons do not overwrite the settings selected in the menu. Every next session, the settings from the menu will be applied and the expo-peaking selected with these buttons will be reset.