Using the Bintel focal reducer 0.5x will approximately halve the focal ratio of your telescope, resulting in wider fields of view and cutting down on exposure times.
Best used on scopes with longer focal lengths where wider fields are required or desired. In a typical Schmidt Cassegrain at f/10 it will reduce it down to f/5.
The actual focal length reduction will vary a little over or under 0.5x depending on where the focal reducer is placed exactly in the optical path. Additional spacer can be used to shorten or lengthen the focal reduction.
The reducer features 2-element fully multi-coated optical design and blacked lens edges in a black anodize aluminium filter cell. It also has additional 2" female threads (M48x0.75) so you can screw or stack additional 2" filters on to this reducer.
It can be used visually, however it is best suited for imaging.