![]() ![]() The Crayford is similar in appearance to a Rack and pinion focuser, but has no teeth on either the rack or the pinion. The Crayford focuser is a simplified focusing mechanism for amateur astronomical telescopes. The telescope is equipped with an electronic 2" Moonlite CS Crayford focuser. Also, for astrophotography, the image does not rotate in the focal plane, as occurs with altazimuth mounts when they are guided to track the target's motion, unless a rotating erector prism or other field-derotator is installed.įocuser - Moonlite High Resolution Stepper Motor Equatorial mounts differ from mechanically simpler altazimuth mounts, which require variable speed motion around both axes to track a fixed object in the sky. The axis of the mount is equipped with a motorized clock drive, that rotates that axis one revolution every 23 hours and 56 minutes in exact sync with the apparent diurnal motion of the sky. In astronomical telescope mounts, the equatorial axis (the right ascension) is paired with a second perpendicular axis of motion (known as the declination). Such an arrangement is called a sidereal drive. The advantage of an equatorial mount lies in its ability to allow the instrument attached to it to stay fixed on any object in the sky that has a diurnal motion by driving one axis at a constant speed. This type of mount is used for astronomical telescopes and cameras. An equatorial mount is a mount for instruments that follows the rotation of the sky (celestial sphere) by having one rotational axis parallel to the Earth's axis of rotation. It's a direct drive mount with high resolution encoders, resulting in no backlash, no periodic error and perfect tracking. The ASA DDM60 Pro is on of the most accurate German Equatorial mounts. Fine adjustment is achieved with a Starlight Instruments 2" Feather Touch focuser with 1.5" travel and 10:1 reduction. The star diagonal in which the blocking filter is installed, is equipped as standard for 1.25" eyepieces and with a T2 camera connection. The Blocking filter is the B1200, that provides a smaller vignetting for imaging. With the matched collimation lens set, the LS60THa is corrected for on axis coma, astigmatism and de-centering aberrations and provides a full spherically corrected flat-field Solar-Telescope. The Pressure Tuner system adapted the Etalon to varying altitudes and atmospheric pressures for optimal performance. This Pressure Tuner system allows a better Etalon adjustment than other systems. An internal etalon with air-pressure tuning adjustment allows for a <0.7 Ångstrom bandwidth. The LS60THa is a Solar Telescope with 60 mm aperture and 500 mm focal length. These telescopes were branded and sold as Robtics, Astro-Tech, Orion and under a few other brand names. In about 2009, Guan Sheng Optical (GSO) corporation, a wholesale optical manufacturer, introduced a line of significantly less expensive Ritchey–Chrétien telescopes. The RC offers good off-axis optical performance, but examples are relatively rare due to the high cost of hyperbolic primary mirror fabrication. As with the other Cassegrain-configuration reflectors, the RC has a very short optical tube assembly and compact design for a given focal length. When focused midway between the sagittal and tangential focusing planes, stars are imaged as circles, making the RC well suited for wide field and photographic observations. The Ritchey–Chrétien design is free of third-order coma and spherical aberration, although it does suffer from fifth-order coma, severe large-angle astigmatism, and comparatively severe field curvature. Since the mid 20th century most large professional research telescopes have been Ritchey–Chrétien configurations. They have large field of view free of optical errors compared to a more conventional reflecting telescope configuration. A Ritchey–Chrétien telescope (or RC) is a specialized Cassegrain telescope that has a hyperbolic primary mirror and a hyperbolic secondary mirror designed to eliminate optical errors (coma). I reduced it with a Astro-Physics CCDT67 reducer, so now it has a focal lenght of 1380 mm with a focal ratio of f/5.5. The Robtics RC10 is a Ritchey-Chrétien Reflector telescope, with a diameter of 250 mm and a focal length of 2000 mm, this results in a focal ratio of f/8. Home Location, The Netherlands Telescope - Robtics RC10 ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |