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Figure 2-17. X-Rite ColorChecker Passport which has replaced the X-Rite ColorChecker Mini.”°
The targets themselves come in a range of sizes and formats, from the full-size
ColorChecker Classic (20.9 x 27.9 cm), preferable for large works, to the now discontinued
ColorChecker Mini (5.7 x 8.2 cm), which has been integrated into the ColorChecker
Passport” (Figure 2-17) and is used for close-up shots or smaller works. Note that the frame
of this new version exhibits luminescence, and should be masked off for use in the
acquisition of luminescence images.
The manufacturer suggests that the typical lifespan of a ColorChecker target is two years.
However, it is important to note that prolonged exposure of these targets to radiation,
particularly UV radiation, will fade the ColorChecker patches and alter the Lab values, thus
affecting the colour calibration procedure.
— Spectralon diffuse reflectance standards
The Spectralon diffuse reflectance standards referred to in Chapter 1 carry out several
functions, including luminance calibration of reflected images, and detection of the presence
of ambient stray radiation in luminescence images. These standards are recommended due
to their durability, chemically inertness and their certified spectral flatness over the UV-VIS¬
NIR spectrum (Figure 2-18).
Version No. 1.0 57 Date : 14/10/2013