![]() By using a telescope with long focal ratio, it is in fact very difficult to capture the weakest details of the objects, even with a long exposure. Therefore, they usually don’t need high magnification (many objects are framed with telescopes with focal length between 500mm and 1000mm) but it is important to use a fast focal ratio (not higher than f/8). These objects have very low brightness and their apparent dimension in the sky may also be quite big. Telescopes for deep-sky objects (galaxies, nebulae or star clusters) Telescope for lunar and planetary astrophotography: Celestron C9.25 Schmidt-Cassegrain with ESATTO 2″ robotic focuser. Schmidt-Cassegrain telescopes are also great for this kind of objects since they provide a very good optical quality, easy to use (since they’re easy to collimate) at still an affordable price. They offer not a wide flat field but a high contrast in its center (which is where we most need it as a planet will always be small against the extent of the telescope framed field). Furthermore, longer-focal length instruments are preferable, because, by adding a planetary camera, it makes easier to obtain high magnifications (a specific Barlow lens is usually applied in the telescope focuser, in front of the camera to increase the focal length, above 2000mm). Among the variety of telescope models, the Maksutov-Cassegrain telescopes are great. The pictures will be averaged to reduce noise, allowing us to apply special filters and improve the contrast level.Ī large-diameter telescope is the most suitable to capture images of the planets, the Moon and the Sun, because it allows high-magnification and, therefore, it captures smaller details. ![]() ![]() In this instance, the technique requires to use the so-called “planetary cameras” with the telescope to record a video on the computer: the video will be composed by different frames and processed by softwares specifically designed for astrophotography (such as Registax or AutoStakkert!) in order to select the best images (namely the images less affected by atmospheric turbulence). These objects are very bright and, in order to obtain excellent images, it is necessary to increase magnification to capture all the smallest details (for example Jupiter’s clouds, Mars polar cap or a thin Moon rima). Telescopes for planets, Moon and Sun at high magnifications Let’s see now how to capture different objects and which telescopes are the most suitable for each situation. Deep-sky astrophotography (galaxies, nebulae, star clusters): since these objects have low brightness it’s important to capture the higher amount possible of light and therefore images are captured with long exposure times (several minutes or hours).Planetary astrophotography (planets, Moon, Sun): objects such as planets or a detail of the Moon surface have a small apparent dimension and, therefore, images have to be recorded with high magnification.Astrophotography is in in fact divided into 2 main classes: However, in order to obtain high-quality images, different acquisition techniques are used and telescopes with different characteristics are suggested. It’s possible to use a standard DSLR or mirrorless camera (properly connected to a telescope) to capture the first images of any celestial object. The best telescope may not be the most powerful, but one you will use the most: find out what is the telescope for astrophotography suitable for you. Because of this, when we have to select the best telescope for our needs we have to choose between a specific-purpose telescope (do we need to photograph the planets or deep-sky objects?) or a more general one. When we use a camera to take a normal picture, we can select the magnification which best suits the object of our image, switching from wide-angle shots (for example 20mm focal length) to higher magnification shots (for example 200mm focal length). This freedom of choice is not possible in astrophotography as, due to telescopes special optical design and the specific characteristics of the objects they are used for, they need a fixed focal length that can be varied with the use of additional accessories but only to some extent.įor example, apart from expensive solutions mostly for professional use, a short focal length telescope, which may be used to photograph deep-sky objects, can hardly be used to capture images of the planets or the moon.
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