香港天文論壇

1. anyone....西區 2. Tennom....上環 3. johncamposhk...工地舂坎角 住TKO 4. ambcyli.....堅尼地城 5. Koichi....鴨利洲 6. SIUSIU...香港仔 7. PaulNg...天后 8. Subaru...港島東 9. A/45...薄扶林 10. Raymond Tse Mid-Levels 11. 物理小子...宿舍: 薄扶林 家: 將軍澳 12. Tinping...港島東 13. cyf.... 西環 14. sodium 田灣 15. 星閃閃-----堅尼地城 16. HoWing...宿舍: 西貢 家: 鴨...

Wah!! 寫:超罕見的傳說中的魚眼, 阿米巴兄見到就快快考慮買返來收藏!
順便俾我地開開眼界啦~~~~

http://cgi.ebay.com/Nikon-2-8-6mm-Fishe ... 286.c0.m14

Wah! 很久不見了!

我相信您應該記得"泥坑"不是我杯茶...6mm確實少見(相信是NASA版本),一般"泥坑"220度魚眼都是8mm的。

Subaru 寫:

Tarepanda 寫:1. 原來Starshing係跟Kingarthur去影,難怪啦,好久不見他上來
2. 支105我都用近1千的價格買,有塵,但拍人的效果确實不錯的
但唔知係咩版本

1. 咦, 有內文?
2. 有由最早期的Sonnar design, 跟住轉了Gauss的P, PC, 到價最硬的PC AI, AI及AIs.

價最硬冇唔係S-接口的PC嗎？

astroboy 寫:我想知道望遠鏡個Optical system o係個Prism 之前會唔會過熱或者heat up 影響個optical path?

Herschel prism should only use with refractor. If reflector are used, the secondary mirror might heat-up and crack!

... Herschel wedges are inherently unsafe. What make the Baader product "safe" is the built in ND 3 filter. However, if you remove the filters for photography or any other purposes, the strong light beam can be dangerous. ... YCH It is not the ND3 filter that make Herschel wedge safe; if a ND3 is u...

謝謝你既資料: >dynamic range< 或者可否說是contrast普遍是CCD/CMOS 的問題,唯有希望佢地已經研究得較好, 見有其他一些討論都幾實用; 不過最令人欣喜既係佢地表示會普及應用, 如果唔用冷卻可以影到三兩分鐘已經好好了。 ps 點解咁耐先將研究作普及化...係咩原因, 分享下等...可以了解多一d都好 :) Sorry to reply in English. I can only input Chinese by writing pad and that is very slow. Dynamic range is not the same as contrast...

sbod 寫:

Skyobs 寫: On the other hand, the year 2006 73P photo was taken with a 0.6m Cassegrain telescope (a big one!) in Tuen Mun. Was there a Space Museum site? Or which organization?

這是一個謎.
http://www.bthc.edu.hk/~astronomy/ccd1.htm

装在近内河货运码头的科学馆货仓.................

有冇好睇呀............

Subaru 寫:

Amoebahydra 寫:嘩..........Astrophysics

從鏡主的表情已經睇到: "吃吃, 邊個支鏡夠我支靚!"

唔........呢個都係！ 哈哈

小心講解，細心聆聽............

高橋 CN212...........

嘩..........Astrophysis

XR250 寫:我師傅現身PTC

都唔知您兩師徒䏲勿..................

LAB 方法我是從這裹學習的。一個color space就能寫一本書絕對不簡單；LAB對弱光color noise處理非常有效。

Dear YL,

Spectacular view with your 24-in Newtonian, especially when observing the blue and red colour nebulousness of M42.

Thanks for sharing

Patrick