First attempt with linear filter grating.

[OlDoinyo]

I would think thar reflective gratings would not have such a tendency to have bandpass issues. But I don't know a source for such a thing.

[Cadmium]

Bandpass issues?

[OlDoinyo]

I was referring to the sharp rolloff below 320 nm. Or perhaps no one cares, I don't know--Baader filters and digital sensors don't do well down there anyway.

[Cadmium]

So you were referring to the usual UV-A bandpass filter and stacks, not the narrow bandpass filters like I used in the Sparticle, most of which are 10nm wide,

and can be found with narrow bandpass' down below 320nm and 300nm even.