Mechanical_vignetting

This updated version more precisely reproduces the distinctive distortion and peripheral darkening characteristic of fisheye lenses.
In this release, both optical vignetting and mechanical vignetting have been recalibrated to achieve a more natural and realistic balance between light falloff and physical shading effects.

Optical vignetting: Smooth edge darkening caused by lens geometry and the angle of light incidence.

Mechanical vignetting: Stronger and more abrupt darkening created when peripheral light rays are physically blocked by lens barrels, filter frames, or hoods.

Enhanced gradient transitions from the center to the edges, along with subtle chromatic shifts, bring greater realism and allow the effect to work seamlessly for both photographic and illustrative renderings.