Sky-Watcher BK 804 AZ3 80/400 telescope

Light and compact astronomical telescope with a diameter of 80 mm and a short focal length of 400 mm. The combination of these two parameters gives a telescope with quite unusual proportions, short, with a very large lens speed of F/5 while remaining light and causing no problems when mounted on the AZ3 mount.

Optical System
The 804AZ3 is a refractor telescope, equipped with a two-element objective lens (achromatic doublet). It is a telescope with rather uncommon optical parameters. A focal length of 400 mm with a diameter of 80 mm gives a lens speed of f/5. Such a telescope allows you to achieve the full spectrum of magnifications using available 1.25" eyepieces.

Mount
The telescope uses an AZ3 alt-azimuth mount. It is a fairly large but at the same time lightweight design that allows the telescope to rotate vertically and horizontally, which is very convenient for landscape observations. The low weight of the mount allows the whole set to be carried easily. On both axes, the mount has slow-motion controls that allow gentle movement of the telescope's field of view.

This mount comes with mounting rings for the telescope; after removing them and purchasing an optional 1/4" adapter, it is possible to mount a standard camera or a spotting scope.

Eyepiece focuser
The telescope is equipped with an eyepiece focuser in the 1.25" standard. It is a rack-and-pinion focuser (the so-called Rack&Pinion focuser). This focuser ends with a mount with a locking screw for the diagonal. A 45" prism diagonal in the 1.25" standard is included in the set. The telescope provides an upright, non-inverted terrestrial image. This focuser is compatible with the Sky-Watcher focuser motor drive.

Technical data:
Optical system: achromatic refractor
Mirror diameter: 80 mm
Focal length: 400 mm
Lens speed: f/5
Limiting magnitude: 12.2 mag
Eyepiece focuser: 1.25"
Mount: AZ3 alt-azimuth
Optical tube weight: 1.5 kg
Manufacturer: Sky Watcher, Taiwan