Calibratings the optics of amateur or semi-professional telescopes requires patience and specific technicl capabilities. It is necessary to point the telescope towards a bright, fixed star and then perform a tuning of mirrors and lenses. When not having a motorised mount or when having to perform the calibration during the day or indoors, a device producing a circular, calibrated dot of light is required. Sinai, together with important firms in the sector of semi-professional astronomy, designed an array of devices for calibrating telescopes. The devices for calibrating the optics are called "artificial stars" and are available in three different models:

Fixed Star: produces a pure white luminous dot of fixed intensity and a calibrated diameter of 50µm. Being battery-operated it is compact and easy to deploy. It is useful when calibrating newtonian or Dobson telescopes.

Adjustable Star: produces a pure white luminous dot with adjustable intensity  and a calibrated diameter of 50µm. The device is switched on and tuned via a graduated knob with 10 levels of intensity. Being battery-operated it is compact and easy to deploy. It is useful when calibrating newtonian, Dobson, Schmidt-Cassegrain and other telescopes.

RGB Star: produces a pure luminous dot of fixed intensity and a calibrated diameter of 50µm. The dot can be of any of the three basic colours (red, green or blue). Being battery-operated it is compact and easy to deploy. It is useful when calibrating refracting telescopes for having a correct evaluation of the chromatic aberration.