Sky-Watcher 90/900 EvoStar AZ-3 Телескоп

The lenticular telescope is intended for beginner astronomy enthusiasts as well as for people looking for equipment for landscape observations. With a diameter of 90mm, it is a telescope that offers greater possibilities than the basic models with a diameter of 60mm or 70mm. The greater stellar range and better resolution allow you to see more objects with better image quality. It is a telescope with f / 10 aperture and 900mm focal length. The telescope with the AZ3 assembly is a light instrument that can be easily packed in a car and taken to the dark, rural sky. Equipped with a 1.25 «prism cap, it allows you to obtain a non-inverted terrestrial image.

Optical system

The BK909AZ3 telescope is a classic achromatic refractor. The lens diameter is 90mm and the focal length is 900mm. The aperture of the lens is equal to f / 10. It is a typical achromatic doublet made of two elements with different refractive indexes, covered with anti-reflective coatings. On the side of the eyepiece lens, in the optical axis, there is a 45-degree prismatic cap that gives an inverted image and 2 Kellner eyepieces with 10mm and 25mm focal lengths. The telescope’s equipment should be supplemented with two eyepieces: short-focus (6-7mm) for the Moon and planets, and another with a focal length of approx. 40mm in order to obtain a wider field of view and greater image clarity.

Installation

The telescope uses the AZ3 azimuth mount. It is quite light but at the same time stable construction that allows you to rotate the telescope vertically and horizontally, which is very convenient for landscape observations. At the same time, this mount is well suited for astronomical observations. The low weight of the assembly allows you to easily carry the entire set. In both axes, the assembly has micromovements that allow you to gently shift the field of view of the telescope, thanks to which we can follow the object as it travels through the sky. This assembly, together with the telescope, has mounting clamps, after removing them and buying an optional 1/4 «adapter, it is possible to hang an ordinary camera or landscape spotting scope.

Spectacle lift

The telescope is equipped with a 1.25 «standard eyepiece extractor. It is a rack lift (the so-called Rack & Pinion lift). The extract is completed with a mounting with a screw that secures the angle cap. The 45-degree prismatic angle cap, standard 1.25» is included in the set. The telescope gives an image of the earth, not inverted. This lift is compatible with the drive for Sky-Watcher lifts.

Astronomical observations

Solar system:

Sunspots (with an appropriate filter), details on the lunar surface — larger than 2 km, stripes in the atmosphere of Jupiter, shadows of the moons on the planet during transits, Cassini’s break in the rings of Saturn, in good conditions 4-5 moons of this planet. Uranus visible as a tiny disk at high magnification, Neptune as a point object.

Celebrities:

About 1.1 million stars across the sky, up to about magnitude 11.5-12, binary and multiple stars separated by more than 1.5 «angularly.

Deep Sky Objects:

Dozens of globular clusters, emission nebulae, planetary nebulae and galaxies, all Messier objects and brighter NGC objects (with many brighter objects visible detail) most of the galaxies remain blurry spots — a larger telescope aperture is needed to observe them.