http://www.sover.net/~maierpho/
They have remarquable prices for narrow band filters... $35 for a 10 nm
passband
filter !
I called them and chatted a bit... I think that they are great... I
needed a passband
filter at 656 nm which would work at 45 degres... they are actually
measuring a filter
for me to check the transmission !
-- Benoit