Bintel's new 2 inches 0.5x focal reducer is threaded to screw onto any 2 inches accessory thread (2 inches eyepieces or photographic adapters)and reduces the effective focal length of your telescope by 0.5X. Double the amount of sky on your CCD 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. The reducer features 2-element fully multi-coated optical design and blackened lens edges in a black anodize aluminum filter cell. Filter threads allow you to screw/stack additional filters on to this reducer. Requires about 20mm of focus in rack. Supplied with protective dust caps on front and rear.