بعد أن استمتعت بمرآة تلسكوبية صغيرة في صباه، قررت أن أخصص عيد ميلاد مهم للاستثمار في تلسكوب جديد بمواصفات معقولة. القدرة على النقل هي عنصر رئيسي، لأن التلسكوب لا يمكن تركه خارج المنزل ويجب نقله بين المنزل أو المخزن للاستخدام. بينما لا ينبغي أن يكون كبيرًا مثل تلسكوب دوبسون، لا أمانع في أداة أثقل طالما يمكن فكها إلى أجزاء ويمكن تحميلها بسهولة في السيارة للرحلات إلى الميدان.
أنا أفكر حاليًا في نماذج من مجموعة Celestron Nexstar Evolution، وخاصة مقارنة مزايا النموذجين 8 بوصة و 9.25 بوصة. اهتمامي الرئيسي هو المراقبة العامة وليس التصوير الفلكي العميق، لذلك أود أي ملاحظات أو تجارب قد تساعد في اتخاذ هذا القرار.
I’d recommend an 8″ model and suggest trying a used one first. SCTs involve some compromises, so it’s worth getting a feel for them before investing $3,000.
What’s your budget?
I’m not a big fan of Celestron mounts. If you can afford more than a Nexstar, I’d recommend a 9.25″ Edge HD with a Losmandy G11 mount, though the mount is pricey. If that’s too much, consider a Skywatcher mount instead.
Don’t forget to budget for eyepieces.
If you want to go all out, the C11 is magnificent – mine was my 60th birthday present.
Keep in mind the focal length of these scopes. They’re not as versatile as you might think. Trying some scopes at an astronomy club would be helpful. I love my C11, but my refractors get more use due to their wider field of view.
It’s a misconception that an SCT is lighter than a Dobsonian of similar size. I’ve owned both, and the Dobsonian was much easier to set up. A 10″ Dobsonian has a tube and mount each weighing about 12 kg, while a 9.25″ Nexstar includes a 10 kg tube, 12 kg tripod, and 7 kg mount. Additionally, the SCT costs roughly five times more.
While I agree about the weight, the compactness of SCTs is a significant advantage. Depending on your constraints, this could be a very important factor to consider.
More aperture is generally better. I own the 9.25″ Evolution, which is a great instrument. It also comes with a sturdier tripod than the 8″ model.
The 9.25″ is near the mount’s maximum capacity, so expect occasional vibrations. I agree with the recommendation to get a reducer for wider fields of view. You can control it with the included hand controller or via smartphone using the built-in Wi-Fi.
Keep in mind the tube is significantly heavier than a Dobsonian’s, so be prepared for that.
For the 9.25, I recommend two essential additions: a reducer and a 2″ diagonal. The 9.25 offers a larger illuminated field and significantly less vignetting with 2″ eyepieces, especially when using a reducer, making it more capable for deep-sky objects. Its slower primary also provides better optics.
For portability, I’d recommend the 8-inch model. I know some people who are starting to find their 9.25-inch scopes less manageable as they get older.
It depends on your age and how futureproof you want the scope to be. If you’re over 60, consider a smaller 8″ model. If you’re 50 or younger and in good health, a larger 9 1/4″ may be suitable. I often see listings where people sell their larger scopes because they can no longer manage them physically.
If you have space for a wheeled cart, you can choose any size you prefer.
The 9.25 is somewhat of a trap. The 8 is quite lightweight, and the aperture difference is minimal. A C11 would be the only worthwhile upgrade, as it’s only a couple kilograms heavier than a C9.25 but offers a significant aperture gain over the C8.