Quote Originally Posted by Mark Fisher View Post
It means that a blue camera filter will only get you part way there, but it may be far enough for the look you want. To really mimic the spectral characteristics you'd need a bandpass filter like those at Edmund optics.....the off the shelf filters tend to be small and very pricey.
A blue dichroic has a pretty sharp cutoff around 470nm. For something a little shorter, perhap the Hoya B370 would be better - The dichroic filters would be around £18 for a 25mm Ø unmounted, a B370, expect to pay upwards of £35 for a one off.

I've used UQG in the past, and they can cut custom sizes out of a range of specialist glass, but expect to pay accordingly.