Calculation of parameters and characteristics of telescopes using different eyepieces and visualization.Settings:- language (Russian, English, Hungarian, Spanish, German, French, Romanian, Croatian, Italian, Sinhala, Norwegian, Persian, Polish, Japanese, Portuguese, Korean, Catalan, Dutch, Arabic, Greek, Malay, Luxembourgish, Hindi, Indonesian , Ukrainian, Hebrew, Sardinian, Czech, Swedish, Finnish, Chinese, Bengali, Tamil, Slovenian, Turkish, Bosnian, Thai, Bulgarian, Vietnamese)- scale- text font size- input by the slider- comparison of telescopes- bookmarks- Moon phases- help- swipeTelescope:- List of telescopes- Diameter- Focal length- FocuserEyepiece:- Eyepiece list- Focal length- Field of view- Barlow lensCamera:- list of cameras- pixel size- image size- matrix size- BinningCalculations:- Magnification- Stellar magnitude- Field of view- Maximum field of view- f-number- Diameter of exit pupil- Angular resolution- Size of craters on Moon- 2D, 1.4D, 1D, 0.7D, 0.5D- Sun- ISSPlanets:- Mercury- Venus- Earth- Mars- Jupiter- Saturn- Uranus- Neptune- PlutoAsteroids:- Ceres- Pallas- Juno- Vesta- Ida- GaspraSatellite:- Moon- Titan- Io- Europa- Ganymede- Callisto- Titania- RayMessier:M1, M8, M13, M16, M17, M20, M27, M31, M33, M42, M45, M51, M57, M58, M63, M64, M74, M78, M81, M82, M83, M88, M97, M99, M100, M101, M104, M108NGC:891, 2359, 2392, 2440, 4565, 4631, 5189, 6302, 6543, 6960, 6979, 7000, 7662IC:1805, 1848, 2118