Celestron C5 會係支好既便攜望遠鏡嗎?
睇spec話得2.72kg
好似好輕咁
Celestron C5 會係支好既便攜望遠鏡嗎?
Re: Celestron C5 會係支好既便攜望遠鏡嗎?
如果主要是用於目視, 而便攜是主要考量, 愚見認為是好的選擇。
強項: 輕便, 性價比高
弱項: 焦比偏高, 反差偏弱
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- 夸克星
- 文章: 3847
- 註冊時間: 週四 09 10月, 2003 21:06
Re: Celestron C5 會係支好既便攜望遠鏡嗎?
Not at all good.
The focal length of C5 is 50 inches, or at 1270 mm giving a minimum amplification around 40X. You cannot go lower because the baffle tube reduces the field of vision. Theoretically a 5 incher should offer a minimum amplification of 20X, at exit pupil of about 6 mm, maintaining no energy loss to the human eye and provide a maximum field of view of about 3 to 4 degrees, depending on which type of eyepiece under use.
This means that a C5 is unable to perform in the rich field application which is easily handled by a RFT Newtonian. A C5 excels in high power but unable to perform in rich field application, making it a mediocre choice to view, say , the total solar eclipse.
The focal length of C5 is 50 inches, or at 1270 mm giving a minimum amplification around 40X. You cannot go lower because the baffle tube reduces the field of vision. Theoretically a 5 incher should offer a minimum amplification of 20X, at exit pupil of about 6 mm, maintaining no energy loss to the human eye and provide a maximum field of view of about 3 to 4 degrees, depending on which type of eyepiece under use.
This means that a C5 is unable to perform in the rich field application which is easily handled by a RFT Newtonian. A C5 excels in high power but unable to perform in rich field application, making it a mediocre choice to view, say , the total solar eclipse.
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- 中子星
- 文章: 1692
- 註冊時間: 週日 11 9月, 2005 01:34
Re: Celestron C5 會係支好既便攜望遠鏡嗎?
I agree, it is a scope for causal observation in a light small package.Chanlunlun 寫: ↑週三 30 8月, 2017 10:32Not at all good.
The focal length of C5 is 50 inches, or at 1270 mm giving a minimum amplification around 40X. You cannot go lower because the baffle tube reduces the field of vision. Theoretically a 5 incher should offer a minimum amplification of 20X, at exit pupil of about 6 mm, maintaining no energy loss to the human eye and provide a maximum field of view of about 3 to 4 degrees, depending on which type of eyepiece under use.
This means that a C5 is unable to perform in the rich field application which is easily handled by a RFT Newtonian. A C5 excels in high power but unable to perform in rich field application, making it a mediocre choice to view, say , the total solar eclipse.
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- 主序星
- 文章: 153
- 註冊時間: 週六 23 8月, 2014 12:04
Re: Celestron C5 會係支好既便攜望遠鏡嗎?
How much $ C5 now?
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