Just now received my new set of 36mm 6nm narrowband Astronomiks, these are a new line from Astronomik and the following tested specs are printed on each filter case:
Ha: 6nm @ 97.8% transmission, good to F3.1
OIII: 6nm @ 93.5% transmission, good to F3.4
SII: 6nm @ 97.4% transmission, good to F2.4
I'll whack'em in asap and see how they work under Moonlight
Mike