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Chanlunlun
週五 13 10月, 2017 11:04
版面: 自製天文望遠鏡 Amateur Telescope Making
主題: 「大牛裁半行動」(40厘米口俓F4.5,兩米身長縮致80厘米)
回覆: 31
觀看: 1150

Re: 「大牛裁半行動」(40厘米口俓F4.5,兩米身長縮致80厘米)

Dears, I don't understand why you need to fold a 16 inch f/4.5 telescope. Folding Newtonian is nothing new and had been existing since long ago but they just appear in small aperture. Anything larger than 6 inch aperture is non practical due to the exceedingly large size of the plane mirror required...
Chanlunlun
週一 02 10月, 2017 19:14
版面: 天文攝影 Astrophotography
主題: 龍門新拍星點的 M8M20
回覆: 4
觀看: 253

Re: 龍門新拍星點的 M8M20

Can Dragon Door be comparable to Yina Mountain ?
Chanlunlun
週六 02 9月, 2017 10:19
版面: 天文攝影 Astrophotography
主題: 2017美國日全食
回覆: 8
觀看: 303

Re: 2017美國日全食

Arch national park + milky way = my dream. I went to Salem for solar eclipse and there were plenty space for free camping both in the central park or in our privately discovered park next to our hotel. A friendly park ranger could also helped us to arrange the camps in the site if in case we heeded ...
Chanlunlun
週四 31 8月, 2017 11:03
版面: 廠製儀器 Factory Equipment
主題: 新手買望遠鏡請教!
回覆: 4
觀看: 415

Re: 新手買望遠鏡請教!

Only at cloudless nights.
Chanlunlun
週三 30 8月, 2017 10:32
版面: 廠製儀器 Factory Equipment
主題: Celestron C5 會係支好既便攜望遠鏡嗎?
回覆: 3
觀看: 293

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 en...
Chanlunlun
週三 09 8月, 2017 08:42
版面: 天文活動消息 Astro Activity News
主題: 2017年美國日全食
回覆: 21
觀看: 1476

Re: 2017年美國日全食

For telescope of this size, it is heavy - 2.2 kg for a 4 inch RFT. While building this telescope 30 years ago, the dominating design philosophy was to use as much metal as possible for rigidity and so you could see that the telescope is using aluminium end rings, bronze focuser and other metallic pa...
Chanlunlun
週二 08 8月, 2017 09:59
版面: 天文活動消息 Astro Activity News
主題: 2017年美國日全食
回覆: 21
觀看: 1476

Re: 2017年美國日全食

明天就耍出發,心情異常興奮,沿途會帶着4吋的RFㄒ,郵輪上覌星和覌看食甚。 [樂奔]
Chanlunlun
週六 05 8月, 2017 06:40
版面: 天文活動消息 Astro Activity News
主題: 2017年美國日全食
回覆: 21
觀看: 1476

Re: 2017年美國日全食

Thanks Mr. Tang.

Where will you go ?
Chanlunlun
週四 03 8月, 2017 10:33
版面: 天文活動消息 Astro Activity News
主題: 2017年美國日全食
回覆: 21
觀看: 1476

Re: 2017年美國日全食

現在距離出發日子尚有6天,正是未出發先興奮。將會帶同4吋RFT一支觀看食甚時的太陽,另20號晚上亦可用作 Salem 郊外觀星之用。
Chanlunlun
週二 25 7月, 2017 19:01
版面: 天文活動消息 Astro Activity News
主題: 16吋鏡今晚出動PTC
回覆: 0
觀看: 179

16吋鏡今晚出動PTC

今晚天氣出乎意料地好,唔出動對自己不起。
Chanlunlun
週二 11 7月, 2017 06:07
版面: 天文攝影 Astrophotography
主題: 2007年內蒙NGC7331高清版
回覆: 4
觀看: 421

Re: 2007年內蒙NGC7331高清版

Never underestimate the power of C8. Excellent shot, first class image by a mediocre C8.
Chanlunlun
週日 02 7月, 2017 14:26
版面: 天文活動消息 Astro Activity News
主題: 天文攝影之應用及深入討論研討會(2017_7) 額滿已截止報名
回覆: 10
觀看: 891

Re: 天文攝影之應用及深入討論研討會(2017_7)

PMed. But I have no idea whether it is a successful PM or not because I am a low tech guy.

So I posted here again.

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