Nobody in the next lab knew how to use the epi-fluorescence illumination (the boss is away) but we figured it out. Basically: turn on the power supply, get the cells in focus while waiting for the little controller screen to say the lamp is warmed up, then slide the filter holder back and forth to find the filter that lets you see glowing cells.
The only trick was finding how to increase the size of the illuminated area to fill the screen (it was small off-center patch of light). I know enough about microscopes to know that it's never a good idea to randomly twiddle knobs to see if things get better, I had to do quite a bit of RTFMing and Google-searching to figure out that one of the mysterious rods on the top of the microscope controlled the opening of a hidden something called the 'luminous field diaphragm', and that the even more mysterious knurled rods beneath it could be used to center the illumination.
That let me discover that a hemocytometer does not work well with epi-fluorescence; I think the glass actually glows. I'm now quizzing the old-timer microbiologists in search of something called a Petroff-Hausser counting chamber, designed for bacteria. If that fails I'll just mix a known concentration of 1 µ polystyrene beads with the cells so I can calibrate the volume of whatever area I'm counting.
3 hours ago in Variety of Life