I did a photo shoot using Dji phantom 4 with application PIX4D at a height of 50m. when I input into the software PIX4D, there are two points (yellow box) shooting passed without shooting. why does it happen?
if the connection between the controller and the drone is broken, images are not taken anymore because the Capture App is responsible for triggering the drone’s camera. However it continues the flight as the waypoints are uploaded to the drone before taking off.
So, probably you lost the connection at a certain point during the mission (and, looking at your flight-plan, it happened when your drone was in the farthest position) and for that small time-range the Capture App was not able to trigger the drone’s camera.
If you’re using the iOS version of the App, you can avoid this behaviour activating Safe mode in the mission settings. When using the Safe mode, pictures will be taken regardless of the connection because the location of when the camera is triggered is uploaded at the beginning. However, the drone stops to take each pictures which makes the flight longer in this mode.
The mode can be changed if you go to: Home screen > Grid Mission > Settings
I hope this helps.