I've never formally studied it. My pet subject is CS tbh. It's just a lens I found one day, picked it up and started inspecting things through it, found it usef

I've never formally studied it. My pet subject is CS tbh. It's just a lens I found one day, picked it up and started inspecting things through it, found it useful, pocketed it and moved on. Comes in handy a lot along with several others I've collected over the years.