Astromania 0.5X Reducer for Photography and Observing - 1.25" Filter Thread (28.5x0.75MM) on Both Sides - Reduces The Focal Length for Visual and Photographic Use

85mm focal length, reduction factor of about 0.5X, depending on spacing. 0.5x focal reducer effectively halves the focal length of a telescope, enabling lower magnification, a wider field of view, and shorter exposure times for astrophotography. 2 lenses for better correction - cemented together and coated, black-anodized aluminum housing. Mounting threads - 1.25" filter thread (28.5x0.75MM) on both sides: Threads into eyepieces, camera adapters, and other accessories with standard 1.25" threads, and can be stacked with additional 1.25" threaded accessories. Intended for use with with longer-focal-ratio telescopes and eyepieces of narrow to moderately-wide apparent fields of view. International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions.