Your note seems to have been truncated (or perhaps I'm truncated (mentally)) but if I got the drift of what you were saying was that the examination of any spectral data relies on the spectra of the illumination. -- and of course you are correct! LED illumination is not as narrow as the catalogs would infer by the stipulation of a nm frequency of illumination. In fact it can be all over the place. This is one of the reasons I am in the process of building a simple reflective/transmissive spectroscope, which at the moment is in hiatus while I concoct a means to position a scale in it (could buy it but this is more fun).
The fluorescent illuminator was constructed possibly out of jealousy of those with "in scope" means of fluorescent illumination. A profound failure by comparison but at least I can get some long wave capability with minimal effort. Let me know if I addressed this satisfactorily.