An achromat or an achromatic lens system is understood to mean a lens system in which the focal length is the same at at least two wavelengths. This reduces the effects of chromatic aberrations and spherical aberrations.
The most common type of achromat is the achromatic doublet, which consists of two lens components that exhibit different degrees of dispersion (color dispersion).
Usually one component is concave (concave) and made of flint glass, and the other is convex (convex) and made of crown glass. Of these two, crown glass has the lowest dispersion.
Other low dispersion glasses can also be used for this purpose. The two lens components were mounted close together, usually even glued together; together they are designed in such a way that the chromatic aberration of one compensates for that of the other.
Celestron Astromaster 70AZ
The AstroMaster 70 AZ is the entry-level model of the series that still offers the possibility to easily track an object in the sky.
The 70mm aperture and azimuthal mount make it an excellent travel companion for your first forays into the starry sky. Enjoy Saturn, the bands of Jupiter and the overwhelming amount of stars in star clusters such as M13 and M15. This telescope is also interesting for the advanced amateur astronomer as a travel telescope and can also be used for observing terrestrial objects. The Astromaster 70AZ comes with two eyepieces of 20 and 10 mm, red dot viewfinder, the Celestron Planetarium Starrynight software and an accessory tray.
The Celestron StarSense technology is the latest trend in telescopes. Forget complicated star charts, inaccurate planetarium apps and computerized montages. With the StarSense Explorer DX102 refractor and its 102mm aperture with optical XLT coating you enjoy improved light transmission and the StarSense technology makes locating objects very easy, fast and accurate.
Within minutes of setting up the telescope, you’ll be navigating the universe with confidence. Place your phone in the unique StarSense dock and launch the StarSense Explorer app (compatible with Android and Apple). After aligning your phone with the telescope’s optics (a quick 2-minute procedure), StarSense Explorer generates a list of all currently visible celestial objects and the exploration can begin.
This 150mm refractor\lens telescope is ideally suited for moon and planet observation with a lot of sharpness and contrast. The 150mm aperture without any form of obstruction makes this telescope a very bright telescope. Somewhat brighter nebulae are therefore also excellent to admire with these binoculars. With some adjustments and filters you can also use the telescope for astrophotography. The companion Advanced VX mount sets a standard for medium-sized telescopes and offers many of the features found on Celestron’s most advanced equatorial mounts.
The Advanced VX mount is designed to deliver superior performance while taking advantage of Celestron’s most advanced technologies: All-Star Polar Alignment, Celestron PWI Telescope Control Software, SkyAlign and Permanently Programmable Periodic Error Correction (PPEC).