Comparison of the Vignetting Effects of Two Identical Fisheye Lenses

AbstractHigh dynamic range (HDR) imaging techniques are increasingly used by lighting researchers in building applications to capture luminances in the field of view. This paper deals with the photometric calibration and more particularly with vignetting effect correction, which is one of the steps necessary to ensure reliable data. The vignetting effects of four similar devices (two identical fisheye lenses successively mounted on two identical cameras) were first determined for several apertures. The symmetry, noninfluence of the color of the target, and the similarity of vignetting between the devices were evaluated with root mean square error. Finally, the mapping function of the fisheye lens was checked. This study shows that the vignetting filters determined for one device (a SIGMA 4.5 mm F2.8 fisheye lens mounted on a CANON 40D camera) can be reasonably used by other researchers using similar photographic materials (that is, the same brands and models).