香港天文論壇

靚到....啞左

咁即係用高ISO係好好多？
我岩岩睇完一個article話用高ISO之後開long exposure noise reduction
部機就會拍dark frame
咁樣高ISO都唔會話花曬

等我下次開高ISO先

anyone 寫:nice shot !

77mm P2 filter 值得購買，我用緊，覺得幫助幾大！

請問再何處拍攝？

如果只係為左影star trail而買既話我又覺得唔值
仲有咩其它用途？
連EQmount影nebula既話可能都會，但未有咁黑既地方比我玩
張相係我住果道既後花園影既

Wah!! 寫:收細光圈到 F10 是為了什么目的?

因為想拖長黎影，同埋支鏡corner to corner最好應該係F/8-10
第一次影，唔知用3.5既話會唔會冇咁好睇
不過呢張相去到corner果時D星星就見倒係一粒粒咁排起黎
ha
遲下再玩過

鄧登凳 寫:手痕

照片有不少不動的點, 應是相機的死點, 另一片紅也應是相機的問題, 請問你有沒有dark frames?

我都唔知點解照片上有不動既點
但平時影相又唔會有事ga bor~
右上角既紅係個moon黎既.....
我仲有約100張相有個moon pass 過，我唔想要，但又唔想唔要咁多相，所以就留少少光
我冇dark frame，咩黎ga？

鄧登凳 寫:

Rocco 寫:Nov8

ISO 1000
F/10
13sec x 500

周圍太光，唔知有冇filter(77mm)可以隔一隔佢呢？

尋晚影果時唔夠電，影得4個鐘
加上落雨，留左部機係出面
好彩部機冇事=_="

有 light pollutions suppression filter by IDAS. Listed price US$329. See http://www.sciencecenter.net/hutech/prices/filters.htm

香港可問tan14有沒有貨。

都幾貴
我岩岩先買左佢既2 inch

Nov8

ISO 1000
F/10
13sec x 500

周圍太光，唔知有冇filter(77mm)可以隔一隔佢呢？

尋晚影果時唔夠電，影得4個鐘
加上落雨，留左部機係出面
好彩部機冇事=_="

MANDII 寫:

Rocco 寫:

MANDII 寫:Any update progress to get the Jupitor in Canada ?

not really....observing Jupiter and its moon is my homework.....lol
the weather is getting cold and cloudy lately.....
i think my next target is star trail =)

外国落雪了？ star trail 系米即系望天打挂呀,哈哈。

未落雪
但成日都陰天
star trail係望天打掛打足成晚 xDDD

MANDII 寫:Any update progress to get the Jupitor in Canada ?

not really....observing Jupiter and its moon is my homework.....lol
the weather is getting cold and cloudy lately.....
i think my next target is star trail =)

M45既blue係幾多wavelength? 睇圖既話hydrogen beta都pass 係short wavelength既blue (即violet)唔pass 咁差幾遠？ Hydrogen beta 係氫既發射線，發射星雲會出多 D。反射星雲如 M45 等將藍光散射，未必有固定波長既發射線。 喔 明白 一時間講到我好混亂，上堂學過既野都亂曬 咁Lumicon既violet係block得多所以影響倒去影M45 M42我睇過人地既評語話IDAS其實已經唔錯，係會冇咁紅，要用PS改 咁樣我明啦 thanks 上堂又點夠實戰咁實際呢 冇錯，不過成年前學既野唔多唔少都比返D prof 啦~哈

M45既blue係幾多wavelength? 睇圖既話hydrogen beta都pass 係short wavelength既blue (即violet)唔pass 咁差幾遠？ M45 is a reflective nebula, dust reflecting light of nearby stars. Stars are very hot bodies which have "black body radiation" (a strange name for something which is not black at all), it is full spectrum ligh...

昇仔 寫:

Rocco 寫: M45既blue係幾多wavelength?
睇圖既話hydrogen beta都pass
係short wavelength既blue (即violet)唔pass
咁差幾遠？

Hydrogen beta 係氫既發射線，發射星雲會出多 D。反射星雲如 M45 等將藍光散射，未必有固定波長既發射線。

喔 明白
一時間講到我好混亂，上堂學過既野都亂曬
咁Lumicon既violet係block得多所以影響倒去影M45
M42我睇過人地既評語話IDAS其實已經唔錯，係會冇咁紅，要用PS改
咁樣我明啦 thanks

M45既blue係幾多wavelength? 睇圖既話hydrogen beta都pass 係short wavelength既blue (即violet)唔pass 咁差幾遠？ M45 is a reflective nebula, dust reflecting light of nearby stars. Stars are very hot bodies which have "black body radiation" (a strange name for something which is not black at all), it is full spectrum ligh...

昇仔 寫:或者講得簡單一 D，lumincon 畀好少藍光過，冇錯可以 cut 左 Mercury lamp 造成既一 D 光害，但同時天體既一些藍光亦無法得到，而呢個影完之後係無法用圖像處理方法補償的。如果你拍 M42，當然多 D 紅光好，因為發射星雲，但係如果你拍 M45，星雲反射藍光多，你就唔好望 lumincon 會出得好。

M45既blue係幾多wavelength?
睇圖既話hydrogen beta都pass
係short wavelength既blue (即violet)唔pass
咁差幾遠？

但Lumicon係唔比blue pass though, 所以係1, 個graph name錯野？ 我讀remote sensing果時唔係用relative transmission呢個字....@@ The blue verticle line on the Lumicon graph, does not represent blue light. It should be the hydrogen beta emission line (at 4861 A). Around 486nm, it is bluish green light. Blue is below 455nm whi...