the use of mirrors : 1. take a 4K camera mounted on the plane , mount in front of the camera 3 mirrors and get 4 pictures from different angles and with good resolution (do crop needed video).. 2....if there is no servo with 360 rotation but you need to look back-you can put mirrors on the sides of the camera so that when you turn to see the picture from behind ....3 it is possible to make a survey under the plane and on the chassis (this is true for classics) .....actually a lot of options especially if you use the rotation of two servos and a camera with zoom ...mirror 1.5 mm cut with scissors in a bowl of water ...the weight of the mirrors with a video no more than 2 grams