New Bintel 0.5x focal reducer is threaded to screw onto any 1.25 inches eyepiece barrel and provides a nominal reduction in magnification of 0.5x. Double the amount of sky on your DSI chip! This reducer will be of particular interest to anyone with DSI or Starshoot type imagers where it is difficult to fit much sky on the chip of the imager. The actual focal length reduction will vary a little over or under 0.5x depending on where the focal reducer is placed in the optical path. For years people have purchased Barlow lenses to double the magnification of their eyepieces. Now you can halve the power of any eyepiece you own. The reducer features 2-element fully multi-coated optical design and blackened lens edges in a black anodize aluminum filter cell. It also has additional filter threads, so you can screw/stack additional filters on to this reducer. Included is a 25mm extension tube to allow variation in the effective reduction. Without 25mm extension tube reduction is around 0.7x With 25mm extension tube reduction should be close to 0.5x original image scale. Some Newtonian and refractor telescopes may have difficulty reaching focus with the reducer attached to an eyepiece. For example: Focal reducer without extension tube requires 10mm in travel to reach focus. Focal reducer with 25mm extension tube requires 35mm in travel to reach focus.