This is the Heisemberg's principle of indetermination

I ask you a question

Why do the photons of light suddenly change direction after the slits ?

Because of the collision with the edges of the slits, maybe ?
Nope ,if so, they should be absorbed

It is because of the Heisemberg's principle

when the the photon is in the slit , you know both its position and the module of the speed but according to the Heisemberg's principle you can not know both position and speed with an unlimited degree of accuracy, thus the photon must change...direction

As you see that has little to do with " measuring tool "

It is the mistery of quantum physics