UFO Sighting in Escondido, California on 2017-07-31 00:00:00 – I was taking picture of sunset took 4 pictures this object is in only one

I pulled over on san pasquale rd to take pictures of a beautiful sunset i never saw anything but when i showed the picture to my dad a week or so later we noticed a vey clear object in one of the pictures he is a member and thought i should send them to you. it is disc shaped dark in color to large to drone you would see propellor to small to be man helicopter what ever ti is its fast it is only in 1 of 4 pictures and i never saw anything flying around.