I think I can write a script what is able to recognize the exact weight of the flying object. I will calculate the rate of falling based on different observation like airfriction, rotation speed, speed decrease etc. With my model I can extract a probability number which I use to make a decision. Easy job. Opencv, tensor flow, some tracker software and php and of course a 16k 4000fps 3d camera will do the job. I am kidding. You are right.