Product No. 52131
When used with a 77mm diameter wide-angle zoom lens, the lens corrects image aberration and distortion*. The lens helps reproduce clear images when mounted on a compatible lens for interchangeable lens cameras (full-frame SLR cameras). * Field curvature and distortion are rectified by approximately 2 f-stops value.
Patent Pending 2015-136497
WHAT ARE & WHY USE INTERNAL CORRECTION LENSES
Fisheye Dome Port 240 / Optical Dome Port II 165 / Optical Dome Port II 230
Canon EF17-40mm F4L USM / Canon EF 16-35mm F4L IS USM / Nikon AF-S 16-35mm F4G ED VR※ / Nikon AF-S Nikkor 18-35mm F3.5-4.5G ED
※Only Fisheye Dome Port 240
[Lens Construction] 1 element in 1 group (AR-multi-coated on both sides)
[Dimensions (WxHxD)] 85 x 8.4mm / 3.3 x 0.3 inches
[Weight] 48g / 1.7oz
[Construction] Optical glass (AR-multi-coated on the both sides) and corrosion-resistant aluminum alloy.