V4L has a control command that allows regular users to send commands to the driver via their API, available in the v4l-utils package. Instead of using the old CPiA driver modern distros use the gspca driver framework which still operates under Video4Linux. As time moved on driver rewrites began and things got shuffled around. I happen to own a QX3 and in the past was able to use the old guides for the old driver to turn the illuminator lamps on and off in older releases of various Linux distros. Some samples of image quality attainable can be found. The resolution and speed of the CMOS chip in the QX3 is quite poor by modern standards but it does function adequately for a basic educational model. This particular microscope has a CMOS imaging chip with a lower lamp for transmitted light to come through a specimen and an upper lamp for light to be reflected off of it, each of which is independently toggled on and off by software. Years ago Mattel released an educational toy microscope called the Intel Play QX3, and later the QX5.
