Several other telescope manufacturers make focal reducers matched to their telescopes; among them are Vixen (www.vixenamerica.com) and Takahashi (www.takahashiamerica.com). General-purpose focal reducers are made by AstroPhysics (www.astro-physics.com), Optec (www.optecinc.com), Lumicon (www. lumicon.com), William Optics (www.williamoptics.com), and other vendors. Lumicon, in particular, makes large-diameter focal reducers to reduce vignetting with larger telescopes.

Before buying a focal reducer, check carefully whether it is designed to work with an SLR camera body (some have A too small) and whether it corrects the aberrations of your type of telescope, since refractors, for instance, are quite different from Schmidt-Cassegrains. Test it carefully when you get it and make sure it works as intended.

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