Classification of HSO rimless lenses

Antlia filter, H-alpha, SII, O3

These d31.d36, 50R, 50s, 65s are frameless filters, which makes it difficult for professionals to distinguish which one is.

Many users often come back to me after they buy it and ask me which piece is what specification

We specially applied a layer of colored paint to the extinction ink of the filter

50. White, R, red, G, green, B, blue

H. Red, s, green, O, blue