My mouse as an optical encoder

Well let's see how this works out on the video upload to Google. I am showing that an optical mouse can be used as a rotary position encoder for a stepper motor. I have a box full of these and have many uses for them. The neat thing here is that I can change the wheel size and get better precision of resolution.
The video got through okay and shows that I can sense position of a wheel with great precision. The video is a bit low on production value, but I hope it gets the point across.