An essential tool for extreme sports and dramatic action shooters. The 0.4X Pro Fisheye Adapter offers an extreme fisheye effect and a high degree of barrel distortion. It exaggerates depth by pulling nearby objects closer and causing distant objects to recede into the background. Advances in high-index / low-dispersion optical glasses, new barrel materials, and exotic anti-reflection coatings, along with the latest in computer-aided-design / computer-aided-manufacturing, are combined to produce lenses of unprecedented quality. Diamond-cut from crystal-clear, water-white optical glass, Opteka lenses are ground and polished to a precise precision. Because all Opteka lenses are designed and manufactured with the highest possible degree of consistency, you can swap lenses mid-shoot with no discernable variation in color or effect. The unprecedented purity, color saturation and repeatability of Opteka lenses virtually eliminate the need for lab color timing corrections caused by other lenses. This puts more creative control where it belongs - in your hands. Opteka lenses stand up to the most rigorous demands on the stage and on location. Opteka's hard anti-reflective (AR) coating offers protection specially formulated to resist flaking, peeling and scratching. This proprietary AR coating also reduces light loss and flare to less than 1% per surface, compared to untreated glass which has a light loss of 4% per surface. Opteka lenses allow you to shoot with total confidence!