The three wavelengths used for cycling were selected by examining
the wavelengths where ambient illumination was relatively
low to see if a subset of these wavelengths could be used to detect
all anomalies of interest. The 475, 520, and 675 nm wavelengths
were selected based on an understanding of wavelengths appropriate
for detecting organic residues (Wiederoder et al., 2012). When
the device was tested in produce plants, the wavelengths were
found both to be necessary and adequate for detecting all
anomalies of interest, including defects in HDPE and SS surfaces
(Wiederoder et al., accepted for publication). It should be noted