Περιγραφή
Skywatcher offers a wide range of Newtonian telescopes under the Explorer label. The telescopes are available individually or in combination with a variety of mounts.
BD as in “black diamond”: the Explorer BD series of telescopes are very popular with amateur astronomers because they offer high-quality parabolic optics at a very reasonable price. Many amateur astronomers started with an Explorer BD, and many have remained true to their Newtonian to this day.
The Explorer PDS offer the same mirror optics, but are optimised for astrophotography: a more favourable focal position, thinner secondary mirror support and a focuser with gear reduction for focus adjustment.
With a 200mm aperture, this telescope opens up new details in deep sky observing for the observer as compared to smaller telescopes. With 78% more light gathering ability compared to a 150mm telescope, even the delicate spiral arms of many galaxies and additional structures in other nebulae can be observed. Globular clusters, such as the famous M13 cluster in Hercules, can be resolved at their edges to a large degree. The parabolic primary mirror is diffraction limited, allowing sharp images of the object. The very high-contrast optics are optimised by the use of a small secondary mirror and thin secondary mirror spider vanes, allowing sharp and bright planetary observing even at higher magnification. The OTA has a solid 2-inch Crayford focuser for a low image shift focusing – of particular importance at high magnifications and for astrophotography. The use of 2 inch eyepieces allows the maximum possible field of view to be exploited. The telescope has an f5 aperture ratio, putting it in the class of ‘fast’ Newtonian telescopes, so this telescope is particularly well suited to astrophotography.
The OTA is also visually a real gem, featuring an elegant design for the both OTA and finder scope in an aesthetically pleasing shimmering black.
The advantages in a nutshell:
- relatively high light gathering power thanks to 200mm aperture
- resistant to the effects of vibration and wind
- diffraction limited parabolic primary mirror
- high-contrast image due to thin secondary mirror spider vanes and small secondary mirror
- well suited to astrophotography due to the ‘fast’ optics
