It is becoming a very interesting discussion!
about ausastronomer: "The Pentax XW's, which use multi layer partial phase coatings, have a transmission > 90% across the entire visible spectrum; and in the critical range from 500 nm to 620 nm they achieve almost 95% light transmission (96% @ 550 nm [green light])."
But....this is the transmission for each single optical surface, correct? It means a light loss of 4-5% x each optical surface, I suppose. I cannot belive the light comes out from the eyepiece with a total of 5% light loss. (if you say YES
I will buy some XW just tomorrow!!!).
about the warm colors of Clave', I agree,
about mplanet62: very interesting link! I hope this new coating will work fine for astronomical optics as well, because, it is not exactly the same thing of a terrestrial optic. But if it works, I will buy some other "TV eyepiece" with this coating!
Cheers
Fabrizio
PS I love Brandon eyepieces as well as Clave' and Zeiss eyepieces
PS2 can you help me?: what is the light transmission of the best diagonal mirror?