Oldal 66 [66]
SRS-99
be — essem SRS-80
- —~— SRS-75
—— SRS-60
- - - SRS-50
—— —-——_—$_——— SRS-40
f° /Meenlepherical % Reflectance
/
|
|
104" szültem —————— = SRS-20
— ———— — SRS-10
— a SRS-05
) | = ,RS-02
nw 400 4400 400 1000 1200 1400 tex 1600 noe 2200 2400 Aw)
Wavelength (nm)
Figure 2-18. The reference grey scale (Spectralon) and their reflectance spectra.*° The grey scale
shows constant reflectance in the UV-VIS-IR sensitivity range of a silicon-based CCD/CMOS sensor.
Spectralon diffuse reflectance standards are manufactured by Labsphere”’ and are available
individually, with typical reflectance values ranging from 2% to 99%, and are also available in
sets. Although the inclusion in the frame of a number of these standards within this range is
considered beneficial and would be recommended, it is realized that these are not
inexpensive items. The minimum requirement in order to carry out the post-processing
methods proposed is thus the 99% Spectralon diffuse reflectance standard (Figure 2-19).
Figure 2-19. The 99% Spectralon diffuse reflectance standard."
The Spectralon diffuse reflectance grey scale is not commercially available at present and is
custom-made, from patches of Spectralon material from the following reflectance values
(white to black); 99%, 75%, 60%, 50% 20%, 10% (two of these) and 2%.
Version No. 1.0 58 Date : 14/10/2013