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GSO's 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.


Free aperture22.5 mm
Optical systemmulti-coated doublet
Reducing factor0.5x (depending on the projection distance)
Function0.5x Reducer for Visual and Astrophotography
Max. distance to the camera sensorapprox. 55 mm

1.25" filter thread (M 28.5 x 0.6) on both sides

GSO 0.5x Focal Reducer 1.25" with 25mm extension tube

Sales Tax Included
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