I have a round of 20-some glass discs coated with GEL substrates need to mount for solar exposure as close to the Summer Solstice here to test some caching theories.

I used spring saps from cedar, american storax and wild cherry with a tester for wild lettuce gum on at least one disc to see if I get, as I believe, specific outer spectral gateways which can be opened easiest on the equinox & solstice; each bearing different path initiators. I can then look to see which gel if any offers storage and recall specific to its construction materials.

I wanted to test on the Spring Equinox but was not able to get gel materials constructed in time. I need to build some permanent jigs for better everythings.

I have found some of the calculators from here useful for mounting purposes - https://lightingcalculator.org/light-beam-angle-calculator/