What is focal length of Schmidt-Cassegrain telescope?
The primary mirror of an SCT usually has a focal length only about twice its diameter. For example, an 8″ telescope would have a primary mirror focal length of about 16″. This focuses the light to a point 16″ in front of the mirror.
How do you focus a Schmidt-Cassegrain telescope?
The focusing knob, which moves the primary mirror, is on the rear cell of the telescope just below the star diagonal and eyepiece. Turn the focusing knob until the image is sharp. If the knob will not turn, it has reached the end of its travel on the focusing mechanism.
Which is better Schmidt-Cassegrain or Maksutov Cassegrain?
The main difference between Schmidt-Cassegrains and Maksutov-Cassegrains is the corrector lens at the front of the telescope. Both scopes use spherical mirrors which induce spherical aberration. Also, Maksutov-Cassegrains usually have longer focal ratios than SCTs, making them less well-suited for deep-sky photography.
What is the best focal ratio for a telescope?
For such objects, a focal ratio of f/10 or more is ideal. But if you want to see wide views of star clusters, galaxies, and the Milky Way, a lower focal ratio is better. You get less magnification, but you see more of the sky. Wide field telescopes have a focal ratio of f/7 or less.
What is a Schmidt Cassegrain telescope good for?
The compact design makes it very portable for its given aperture, which adds to its marketability. Their high f-ratio means they are not a wide-field telescope like their Schmidt camera predecessor, but they are good for more narrow-field deep sky and planetary viewing.
What can you see with an 8 inch Schmidt Cassegrain telescope?
4. Celestron NexStar Evolution 8 Schmidt Cassegrain Telescope. The NexStar 8 telescope also has a 200mm lens and offers spectacular views of the moon, planets, and deep sky objects.
Do Schmidt Cassegrain need collimation?
Precise collimation is essential to good performance for any Schmidt-Cassegrain telescope. For SCTs, it’s done by small adjustments to the tilt and position of the secondary mirror in its cell.
