Astronomical midday (Photo voltaic midday, Zenith) — in relation to your celestial body, as an example on the Sunlight, zenith is the best position achieved because of the Solar in the entire process of visible motion in orbit, relative to the observer. Viewing the Sun through light-weight-concentrating optics for instance https://werkbankkinder53197.wikijournalist.com/4625286/coast_transmission_for_dummies