This paper discusses one of the steps of the photometric calibration procedure: the correction of the brightness decrease observed from the center of the picture to its periphery, commonly called the vignetting effect, as illustrated in Fig.
When using HDR techniques and fisheye lenses for luminance measurements, it is necessary to correct for the vignetting effect in order to obtain reliable data.
Different methodologies have been explored in the literature to determine the vignetting effect of lenses.
Anaokar and Moeck [2005] determined the vignetting effect of a nonwide angle lens for a single aperture (f/7.9).
In an evaluation of the potential of HDR photography as a luminance data tool, Inanici described the way to determine the vignetting effect of a fisheye lens [Inanici 2006].
Another study determined the vignetting effect of a similar fisheye lens [Jacobs and Wilson 2007].
Researchers using HDR techniques as a luminance data acquisition tool determine the proper vignetting corrections to apply to their lens.