Astromania 0.5X Focal Reducer for Telescope, Fully Multi Coated Field Corrector Imaging Accessory for Telescope Eyepiece Visual and Photography Use -

Astromania 0.5X Focal Reducer for Telescope, Fully Multi Coated Field Corrector Imaging Accessory for Telescope Eyepiece Visual and Photography 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 with 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 inch filter thread 28.5x0.75 mm on both sides; threads into eyepieces; camera adapters; and other accessories with standard 1.25 inch threads; and can be stacked with additional 1.25 inch threaded accessories Free light transmission: 22.5mm lens aperture; can be used with additional spacers available separately to achieve further focal reduction Intended for use with with longer focal ratio telescopes and eyepieces of narrow to moderately wide apparent fields of view Astromania 0.5X Reducer halves the focal length of your telescope, giving you a much wider field of view. You can use this, for example, for doing astrophotography using an astronomy webcam. Using the reducer is ingeniously simple - it is threaded for attaching to a 1.25" filter thread, which lets you easily screw it into any 1.25" eyepiece or 1.25" camera adapter. Screw the Astromania reducer into the filter thread on your camera and so double the size of the photographic image field. This lets you take images of much larger areas of the lunar surface, for example. The reducer is also great for taking videos of the Moon using your webcam. You can obtain even larger image fields with your astronomy webcam if you attach an extension tube (e.g. 25mm) between the reducer and camera.Screw the reducer into a 1.25" eyepiece and you have a smaller magnification and hence a significantly larger field of view. You can use the reducer if you don't have the correct eyepiece. The reducer is optimal for achieving a focal length of up to about 25mm.