What is cinematography? 
It has to do with the science or art of motion pictures.
I like motion pictures
So do I, especially when the motion picture is perfected to an artistic level. Science and art are very prevalent.
When was the first motion picture?
I'm not sure, but it was likely not made on an electronic image sensor since they are very new.
OK
Also, a lens is usually used to repeatedly focus the light into the sensor.
Really?
Yeah, they focus the light reflected from objects into real images.