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Askar F3.9 Full Frame Reducer for FRA400 / FRA500 Astrographs

by Askar
$249.00
SKU FRA400-7XR25

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Askar provides a F3.9 full frame reducer for FRA400 Astrograph, further reducing the focal length and thus shortening the exposure time on its original 400 focal length and f/5.6 focal ratio design basis. The reduction factor is 0.7×, and the reduced focal length is 280mm, which can satisfy most deep-sky astrophotography. The back focus is standard 55mm. The reducer has built-in M48×0.75 thread, easy for the attachment of 2" filters.