GSO 0.5X Focal Reducer 1.25″ with 25mm Extension Tube

Focal Reducer Product Details GSO’s popular 1.25″ 0.5x focal reducer screws on to any accessory such as eyepieces, camera adapters, etc. that accepts standard 1.25″ threaded filters and provides a nominal reduction of 0.5x. Use of this focal reducer effectively halves the focal ratio of your telescope, resulting in a wider field of view and significantly shortened exposure times for astrophotography. For example, use of this reducer will convert an f/10 telescope into an f/5 scope. The 2-element reducer features fully multi-coated optics in a black-anodized aluminum filter cell. It also has additional 1.25″ female threads so you can screw/stack additional 1.25″ filters on to this reducer. This focal reducer will work well for visual use too when coupled with the right kind of eyepieces and telescopes; it is not recommended for very fast scopes or very wide angle eyepieces for visual applications. Note that the use of any optical element like barlows and focal reducers changes the focus point of your telescope, requiring additional in-focus or out-focus travel. The exact amount of focus travel required will depend on the optics and mechanics of your specific set-up (telescope, diagonal (if used), barlow/reducer, and eyepiece). Hence, be aware that you may not be able to reach focus with all eyepieces or in all configurations with a given barlow/reducer. In our tests, when screwed into an eyepiece, this focal reducer required approximately 8mm of additional in-focus travel so please make sure that your focuser can accommodate this travel requirement. Focal Reducer Specifications Focal length (estimated) = 101 – 103mm (3.98 – 4.06″) Total item length (including external thread) = 13mm (0.51″) Total item length (excluding external thread) = 10mm (0.39″) Clear aperture = 22mm (0.87″) Weight = 15gms Made in Taiwan Sales Package 1.25″ GSO 0.5X Focal Reducer – 1, 25mm Extension Tube – 1