@ Chris:
This was done with the YOC-6-3 excitation filter (3mm thick) combined with the blue filter block. The YOC-6-3 works with ultraviolet excitation, see below curve.Your Beautiful front-page image - what wavelengths is that working with?
According Crystaltechno (a producer of similar filters) the curve should look like this:
The barrier filter in the filter block itself (with Lomo always separate from the excitation filters) has a transmission bandwith from 420 to 500 nm. This is basically blue light, while the actual picture shows more than that.
...What do you think?
Below photo was done with the same combination. The colours are not completely consistent with those in previous homepage image. This may be because of -besides different post-processing- it's a different fern and the relay collector lens was upgraded by an additional concave lens in the front.