Re: Spikes in the reflected spectrum

Erik Nikkanen wrote:

> There has been talk of spikes in the light source.  What I would like to
> know is if there are spikes in the reflected spectrums of pigments or
> materials that are illuminated with smooth light sources.
>
> Do the spikes tend to be mostly illumination related phenomena?
>
> Erik

Dear Mr. Nikkanen,

During the past two years I have been measuring thousands of color samples
with the goal of producing a commercially available database. During these
measurements the most "spikey" of the common reflective samples are those
with fluorescent colorants. This would be "white" objects with fluorescent
whitening agents and fluoresent colorants such as DayGlo. There are,
however, some rare earth reflective standards, such as erbium oxide and
holmium oxide which I have used in the past that have some extremely narrow
bandwidth "spikes" which are used for checking spectrophotometer wavelength
accuracy. Labsphere makes these as Spectralon(r) standards.

Robin Myers