If you trigger a shot in Smart Mode and the scene is too dark, Arsenal will take a series of calibration shots to determine the best exposure settings.
If your camera is set to AV mode you will receive a message indicating to move your camera to Manual mode.
After you move the dial into Manual mode on your camera, trigger the shot through the App. Arsenal will run through some calibrations to determine the best settings and then complete a final shot.
If you need to cancel the shot, hit the trigger button again once.