I know we got lots of dirt cheap microscope enthusiasts here, but at a recent event (funded by GOSH and Sloan from the event funding giveaway) @alex9000 showed the cheapest and quickest way i have seen to have 30 5 year old kids build and use their own microscopes in minutes l!
tape the lens over the widest angle camera lens on the back of your phone
let the kids loose! Since you are using phones, i had some of the kids send their observation straight to inaturalist. They could auto-ID many things! This included some citronella ants, that made us curious if the ants smelled or tasted like lemongrass, and within about 5 minutes, an ant-licking craze started and the kids had a blast.
(I don’t think i posted this here before, but sorry for double posting if i did!)
Ha! Quite some classics here!
The laser lenses work perfectly fine for many “macro” applications… go even cheaper by just adding a drop of water and use the spherical meniscus to magnify