The 0.4X Super Fisheye Adapter provides an extreme fisheye effect and a high degree of barrel distortion without vignetting It exaggerates depth by pulling nearby objects closer and causing distant objects to recede into the horizon. Advances in high-index / low-dispersion optical glasses . new barrel materials . and anti-reflection coatings . along with the latest in computer-aided-design / computer-aided-manufacturing Crystal optics AR coating reduces light loss and flare to less than 1% per surface BAB (Internal Black Almite Barrel) Black matte satin finish which reduces reflections. BRG (Black Rimmed Glass) Reduces the chance of light reflecting off the edge.