The SkyWatcher 0.86x coma corrector was originally designed for the SkyWatcher Quattro 150/600 Newtonian tube, but it can also be used with other bright 800 mm and 1000 mm focal length tubes for astrophotography.
Newton telescopes (astrographs) for photographic use are "one-armed" giants without a proper coma corrector. Without this accessory, the stars will only be point-like in the centre of the image due to the high brightness, but will soon become distorted as you move outwards. The multiplier of 0.86x increases the brightness from F4 to F3.44, while the reduced focal length also increases the area imaged. The coma corrector can be used up to APS-C sensor size.
The distance between the sensor and the corrector is the usual 55 mm.The camera end of the coma corrector is equipped with an M48 thread for camera attachment, while the other end has a threaded connection for 2" filters.