You can set the Camera app to save your pictures and videos directly to your SD card to keep the internal storage of the device free for app data.
To Save to SD Card
1. Open the Camera app.
2. Open Settings.
3. Storage > select SD card.
Note: If you do not see the option to select the SD card as a storage location and have the SD card inserted, please make sure your SD card is formatted as a portable storage device.
To Format the SD Card
1. Go to Settings.
2. Select Storage.
3. Press the name of the SD card.
4. Press the three points in the upper right corner > Press "Format as portable"