Patent attributes
One or more slit arc-shaped (vertex) illuminators (SAVI) have unique interactions when illuminating objects, especially convex or concave curves on spheroidal objects such as the human face creating proximity dependent enhanced dynamic illumination. When multiple SAVI are used, with adjoining vertices, adjustments made to the intensity of individual SAVI dramatically change the visual appearance of convex and concave radial curves shapes on the subject. In portrait photography, the illumination balance of opposing SAVIs offers novel controlled distortion that adjusts facial contours to achieve a desired effect, e.g., apparent thinning or other esthetic goals. When photographing different human skin types (light vs. dark tones) the arc geometry of the beams also manipulates the BDRF (Bidirectional reflectance distribution function) rendering evenly distributed illumination boundaries while also avoiding distortions (toroidal or curvature flattening) associated with other illumination shapes such as squares, rectangles, or circles.