As mentioned in other threads I am doing some discovery on some equipment that was left in the home I purchased. One of the more impressive items is the (outdated) Vidikron Vision One attached to the ceiling in my new home theater. On top of the projector is what looks like another projector, but I haven't had a chance to take a closer look at it (figuring out how to safely use the Chief Lift now). Does anyone know what the top, front lens is? I've included a front and back photo for help.
Ironically I figured it out when screwing around with the CRT last night - it is used for auto convergence. Unfortunately I receive an error when using it (eg "Magnitude"). As you can problem notice I don't get around to calibrating the machine as much as I want.