The various sun photometers, radiometers and cameras on the table are used every day at solar noon when the sun is not blocked by clouds. See Wikimedia and www.forrestmims.org for 25-year charts of total ozone, total water vapor and optical depth (haze). Mims' original LED sun photometer (placed in service during fall 1989) is in his left hand. Two Microtops II are in his right hand. One is among the very first (1997) and the other is the only MicroTOPS II with LEDs as photodetectors. The photo was made by Minnie C. Mims on 4 Feb 2016 with a Sony a6000.