The SkyWatcher 90/900 refractor on an AZ-3 mount is essentially a classic astronomical instrument, optimised by the manufacturer for daytime nature observation.
While the astronomical version comes with an equatorial mount, the spotting scope version is mounted on an AZ-3 alt-azimuth mount, which is highly stable and features slow-motion controls—essential at high magnifications. Another difference is that the telescope is equipped with an Amici prism, providing an upright, correctly oriented image similar to that seen through a spotting scope.
The supplied 10 mm and 25 mm Barium eyepieces provide magnifications of 90x and 36x, respectively, while additional optional eyepieces can be used to achieve other magnification ranges.
The SkyWatcher 90/900 refractor is well suited for sightseeing, nature observation and observing passing aircraft. With a T2 adapter, it can also serve as a quasi-manual 900 mm telephoto lens for DSLR cameras.
Of course, if you purchase a mirror diagonal separately for your spotting scope, it can also be used for astronomy. Although alt-azimuth mounts are primarily optimised for daytime observation, the Moon and planets are still well worth observing. For this purpose, a 2x Barlow lens is recommended, providing 180x magnification with the supplied 10 mm eyepiece. This is also the telescope's maximum theoretical magnification.

