The Logitech Quickcam Express was taken apart to reveal an electronics board with integrated camera chip and
a mounted lens. The lens is located on the board with a plastic
spider in which it is screwed. Screwing the lens in and or out
adjusts the focus.
For the CentreCam application a fixed focus is used. Trial and error
showed that this camera would focus in as close and 5 mm but about a 20 mm
focus point is ideal for the CenreCam.
The picture opposite shows the camera components.
The lens and spider has been removed here and the CCD camera chip is
clearly seen.