The 0.75x reducer can bring Askar 71F's focal ratio down to F5.2. This is a standard reducer with field flattening capabilities as well. A shorter focal ratio allows the OTA to have a wider field of view and faster exposure times, making it suitable for capturing large areas of nebulae, star clusters, and faint, fast-moving celestial objects. The 0.75x reducer adopts a triplet design and supports a 44mm full-frame image circle. The overall weight is 0.23 kg. The back focus from the M48 thread is a standard 55mm. Both end threads are M59*1. The 71F photographic extension tube has two sizes of M54*0.75 and M48*0.75 adapters, which can be directly and easily connected to the 71F 0.75x reducer for use. At the same time, the adapter has a built-in M48*0.75 2-inch filter thread, which can be directly installed and used. The overall CNC machined, both end threaded metal caps prevent ash when not in use. Specifications (After attaching) 71F Focal length 369mm (After attaching) 71F Focal ratio f/5.2 Lens Number Triplet design Back Focus 55mm(from the base of M48 male thread) Weight 0.23kg Rear-end thread type M59*1
