The digital infrared reflectogram
has poor optical qualities. In addition
to a low resolution, each camera has
a distinct pattern of linear and tonal
distortions. Once the image has
been digitized, the tonal distortions
can be corrected on the computer.
The right eye from Portrait of a Man (1) is examined with IRR and digitally captured (2). A standard monochrome greycard (3) is also documented with IRR, which exposes the exact tonal distortions of the camera (4). Since both images are digital data, it is possible to subtract these distortions from the IRR of the eye, to correct the distortions (5).
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