有 50 筆資料符合您搜尋的條件

CHYeung
週一 02 3月, 2009 15:38
版面: 廠製儀器 Factory Equipment
主題: canon 400mmF 5.6L vs maxvision ED102 F 7
回覆: 5
觀看: 2442

THe 102 mm f/7 has a focal length of ~700 mm which is much longer than the 400 mm f/5.6 and this impose a much higher requirement for the equatorial mount.


CH Yeung
CHYeung
週四 26 2月, 2009 20:52
版面: 廠製儀器 Factory Equipment
主題: [團購]透紫外/紅外濾鏡 (David, Xiaoer, noodle, simonii, A/45, Raymond)
回覆: 102
觀看: 21938

Wah! Please check PM

Dear Wah!,

Please check PM.


CH Yeung
CHYeung
週二 24 2月, 2009 14:44
版面: 廠製儀器 Factory Equipment
主題: Vixen SXD 腳架
回覆: 14
觀看: 3650

溫度太低,GP 的軸會轉不動,但 GPD 沒影響。
CHYeung
週四 19 2月, 2009 10:44
版面: 廠製儀器 Factory Equipment
主題: [團購]透紫外/紅外濾鏡 (David, Xiaoer, noodle, simonii, A/45, Raymond)
回覆: 102
觀看: 21938

Re: 我都要

CHYeung 寫:我都要

UV-pass 2mm x 2
IR-pass x 2
智通濾鏡框 x 6

如有其它 cut-off wavelength 的 IR-pass filter, 我都會考慮要。

楊志雄
Dear Wah,

I confirm my order but with a little change.

UV-pass 27.6 mm diameter 2 mm x 2
IR-pass 27.6 mm diameter, 720nm x 1
IR-pass 27.6 mm diameter, 850nm x 1
智通濾鏡框 x 6

Thank you.
CHYeung
週三 18 2月, 2009 14:09
版面: 廠製儀器 Factory Equipment
主題: [團購]透紫外/紅外濾鏡 (David, Xiaoer, noodle, simonii, A/45, Raymond)
回覆: 102
觀看: 21938

我都要

我都要

UV-pass 2mm x 2
IR-pass x 2
智通濾鏡框 x 6

如有其它 cut-off wavelength 的 IR-pass filter, 我都會考慮要。

楊志雄
CHYeung
週三 11 2月, 2009 13:48
版面: 天文攝影 Astrophotography
主題: 請高手指教:元宵節月亮
回覆: 5
觀看: 2892

What focal length are you suing? Is it 300 mm (the logest end of your lens)?

If you are using a 300 mm camera lens, the image is just about 3 mm in diameter and this is it.
CHYeung
週一 09 2月, 2009 12:54
版面: 天文物理 Astrophysics
主題: 韓國人造太陽成功發電
回覆: 19
觀看: 15722

noname2002002 寫:希望中國有朝一日都能參加呢一類的前緣研究...
China has a similar setup and had started test runs since September 2006.

<http://english.peopledaily.com.cn/20060 ... 07241.html>
CHYeung
週五 23 1月, 2009 16:21
版面: 二手交易場 Second Hand Area
主題: 有野賣 (Cheap cheap 地)
回覆: 12
觀看: 7254

alget 寫:You are welcome!

寶源光學曾經在澳門生產過相機, 想不到還有生產望遠鏡. :roll:

是1970至1980年代的產品嗎? 造型相當古典, 看起來很穩重呢. :D
寶源光學的廠房當年設於北角英皇道(今天是港運城側的香港大學 SPACE 校舍)和鯽魚涌英皇道(今天的 太古坊英皇道的部分?)。當年規範很大,除生產自家品牌,亦代工生產攝影機和雙筒望遠鏡。當年(七十至八十年代初)在鴨寮街很容易買到寶源光學的次品雙筒望遠鏡物鏡。
CHYeung
週一 20 10月, 2008 17:57
版面: 廠製儀器 Factory Equipment
主題: 卡式顯微鏡
回覆: 10
觀看: 6441

The objective can be mounted onto a microscope to replace the ordinary objective. You may also use it as an extreme close-up "lenses" but you have to find out the designed "tube length". The tube-length is the distance between the optical center of the optical system and the conjugate focal plane, i...
CHYeung
週六 18 10月, 2008 12:07
版面: 廠製儀器 Factory Equipment
主題: 卡式顯微鏡
回覆: 10
觀看: 6441

This reflecting microscope objectives are mainly for the IR range.
CHYeung
週一 29 9月, 2008 14:49
版面: 氣象地理 Weather & Geography
主題: 如何測量經緯度?
回覆: 38
觀看: 22235

In 1761, the British inventor, John Harrison had already produced his 4th marine chronometer (H4) that is accurate to 5 seconds for the journey from England to Jamaica, corresponding to an error of 1.25 minutes in longitude or 1 nautical mile in distance. His fifth marine chronometer (H5) was tested...
CHYeung
週一 29 9月, 2008 12:09
版面: 氣象地理 Weather & Geography
主題: 如何測量經緯度?
回覆: 38
觀看: 22235

Longitude measurements are done by measurement of time of meridian transit of heavenly objects. Time is kept by a "highly accurate" marine chronometer. http://en.wikipedia.org/wiki/Marine_chronometer Latitude is determined by the zenith distance of heavenly objects when they transit the local meridi...
CHYeung
週一 29 9月, 2008 11:14
版面: 自製天文儀器 diy Astro Equipment
主題: 白電油
回覆: 2
觀看: 4174

五金舖

售賣火水、石油氣、潤滑油等的石油產品分銷商
CHYeung
週四 25 9月, 2008 14:42
版面: 天文話題 Everything about Astronomy
主題: [另類理論] 利用孙氏定律准确计算星球个层次物质
回覆: 49
觀看: 15568

好奇問: 我想信佢唔會放棄佢套理論, 同時好難說服佢, 一般人對他的言論恐怕不會有興趣...... 大家為什麼依然願意花時間去回應他呢? :roll: I responded because his theory is a very good example of pseudoscience. By responding to his post and challenging him will demonstrate to those less knowledgeable what is behind a genuine scientific theory. I do not expect ...
CHYeung
週四 25 9月, 2008 11:36
版面: 天文話題 Everything about Astronomy
主題: [另類理論] 利用孙氏定律准确计算星球个层次物质
回覆: 49
觀看: 15568

Re: 请问地球O点至空气大气层边缘最近距离12869.3882(公里)

你认为小学生能计算出来吗?地球O点至空气大气层边缘最近距离12869.3882(公里),也就是和恒星的氢氦大气层相交的最近距离。假如对着月亮发射火箭,[ size=18]从地球O点至12869.3882(公里)就是空气大气层的界点,超出12869.3882(公里),就是氢氦大气层[/size] ,这些小学生都能计算出来?请问金星氢氦大气层你计算是多少公里?知识不要仅限于书本上,书本也是人们在不断地探索中总结出来的,虚心使人进步,骄傲使人落后。尊重别人就是尊重自己。要以理服人。 孫先生, 你的文章中有很多名辭並不是常用的,我和其它同好都不能理解,請你一一詳細定義及解釋,如 空气大气层边缘 氢氦...

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