Kindly follow the mentioned steps to resolve the issue in your device.
1- Set the high camera resolution (Open camera > on the top of the screen ratio option is available (next to the timer option) > select 3:4 H for higher resolution).
2- Turn on the Auto Flash (If Available in the Device).
3- Reset the Camera (Camera > Settings > Reset of camera setting).
4- Software update via FOTA or Smart switch PC suite.
For further assistance, register your concern in Samsung members application (Open Samsung members app >> click on “+“icon > send feedback >> error report / ask question).
Team Samsung Members