0.7X Focal Reducer for EdgeHD8/ HD11Scopes&Optical Tubes 0.7X Focal Reducer for EdgeHD8/ HD14 Scopes&Optical Tubes Features: EdgeHD8" The 0.7x Reducer Lens for EdgeHD8 from adds one full f-stop of exposure speed and broadens the field of view of the 8" configuration of EdgeHD optical tube. This telescope accessory has a fully multicoated optical path featuring high-transmission lanthanum glass elements with blackened edges, delivering color faithful images that are contrast-rich and crisp from center to edge. A 105mm back focus distance accommodates additional imaging accessories and a wide range of cameras, including the Nightscape CCD and DSLRs. The 0.7x Reducer Lens has an aluminum housing that is precisely machined to ensure exact spacing and alignment of the optical elements. EdgeHD 11" The EdgeHD .7x Reducer Makes Your EdgeHD 1100 One Full F-Stop Faster Than f/10, Reducing Your Exposure Time by One-Half to Capture the Same Brightness of Object 5-element lens design Maintains similar flat-field performance as native Edge HD optical design Increases Field of View by 43% to Better Capture Wide Field Images Threads Directly onto the 3.25" threads of the EdgeHD which Reduces Mechanical Vignetting and Allows for use with Larger (Full Frame) Sensors and Off-Axis Guiders