親子觀星會

討論區 => 觀測分享 => 主題作者是: yao 於 2013-07-07 17:44:12



主題: 沙鹿的星空
作者: yao2013-07-07 17:44:12
器材:ED 22X70(未來會用25x100,4inchf10refracotor,C11...............)
時間:大部份是前5,6天所觀測;少數是約2星期前
天氣:狀況觀測前下午6點有下10幾分鐘的雨
         透明度definetly above avage
       NELM:about 4?(both eyes not fully correted for near sightness,or else it might just well above 4
a useful tool for me alone,yet it might be meaningful to whoever sees this report.To be
                 a suggestive of more precise,the outline of Ophiuph stars is deemed distinct,inclusive of   those more elusive ones,such as nu/omicron/xi.(one of those three only sporadically seen)
銀河:只要和無銀河的中天摩羯座相比,過中天的西下銀河仍易見延伸至天鷹座以上只是無法太清楚的分清濃淡
地點:bortle scale red room
       東海與弘光間(近弘光)
       120餘公分寬的可見南方天空陽台
         無直接光源干擾但有些許側方光
觀測方式:全程不用手電筒
首先是器材:ED 22X70(未來會用25x100,4inchf10refracotor,C11...............)
時間:大部份是前5,6天所觀測;少數是約2星期前
天氣:狀況觀測前下午6點有下10幾分鐘的雨
         透明度definetly above avage
       NELM:about 4?(both eyes not fully correted for near sightness,or else it might just well above 4
a useful tool for me alone,yet it might be meaningful to whoever sees this report.To be
                 a suggestive of more precise,the outline of Ophiuph stars is deemed distinct,inclusive of   those more elusive ones,such as nu/omicron/xi.(one of those three only sporadically seen)
銀河:只要和無銀河的中天摩羯座相比,過中天的西下銀河仍易見延伸至天鷹座以上只是無法太清楚的分清濃淡
地點:bortle scale red room
       東海與弘光間(近弘光)
       120餘公分寬的可見南方天空陽台
         無直接光源干擾但有些許側方光
觀測方式:全程不用手電筒
首先是盾牌座的區域此時已過中天2小時.I figure it is of much pleasure to scan through this region by means of nothing but a 22x70,this is a case in point where wide field APOV can truely uncover the grandure of the richichness of this untold beauty-the Scutum,as for all intends and purposes,the aera is littered with cluster,scattered with stars and, if easily seen at all?, riddled with some dark nebulae.這盾牌座的區域我用隨機尋天的方式將明亮的天體一一找出最容易的是
M11:它的星星密集區似乎是在西南方.至於要分辨形狀似乎很難下一次.我看看能不能分解出個別星星或中央的一顆7等亮星
M26:再其次亮度為M26.當然比起M11差的多,不過因為它剛好是8.0等.這8.0等算是一個雙筒鏡觀測的基準意義上就像肉眼極限星等的5.0等這類mark.還好8.0等在我看來just a piece of cake(pun intened).梅西爾中段亮度如果你的儀器&地點&經驗這三者加起來你還很難看到這就糟了
NGC6712:這個球狀星團絕對不叫做考驗.有時它甚至有比M26還亮的錯覺.不小的市視直徑加上不算小的表面亮度,位置亦不難找各位不要忘記它阿
除了這三個容易找且容易看到的深空之外其他有一些憑藉耐心應該有辦法在看到一些只是有一些似有非有的疏散星團還要在確認一次
note 1:It seems no denying,in this case,where there are more numerous star than you can count,it is advantageous to uterlize as wide a AFOV as is possible.
note 2:Gloublar cluster seems to be more readily made out from background than open cluster on grounds that the former has a  more brightness contrast set against background star.
note 3:Scanning the the Scutum in a relaxed fashion provide a better/more pleasurous way than purposely searthing for something seeningly significant,such as M11.
to be continue & many to come


主題: 回覆: 沙鹿的星空
作者: yao2013-07-09 14:35:10
對了,其實我的22X70觀測幾乎都用手持(日後加以說明)

其實盾牌座的區域用高倍率大口徑雙筒觀測是很過癮的
由於盾牌座是個小星座
因此我是用掃瞄的方式
將盾牌座其中的亮天體一一找出
除了上述3個亮天體外
其他都比較暗些
不過我可見M11附近還是有些天體還是有辦法看到
只是要再確認幾次
或是等待更好的透明度
或是再把觀測優質化一些(日後加以說明)

接下來是射手座區域以下(有些M24北方天體不在射手座)
M24:Usually I start with this swath of stars approximately 1.5 degrees in span.It is thought of by me as the geometric center of heavenly bodies within reach of a mere 22x70.M24,hard it is not,but rather magnificient/imposing it is.If memories serves me well,someone counts up to 100 plus stars with ease using 20x80 or something like that.I have not tried this feat,but it might be doable but seriously under this circumstances I ind of doubt it.Nevertheless,diffuse nebulae in and around NGC6603 is a easy pray,using of course nothing bot a humble 22x70.What a sight it is and indeed it is and it was,but will it still be so,that still hangs in the balance considering the ever glowing and growing LP(not pun intended) found here.
M24的雲氣用22X70是輕而易舉的
星星加雲氣使M24成為夏天最壯觀的天體
聽說有外國人用大望遠鏡花1.5小時看個別星星的顏色
不過我沒特別去注意
說實話22X70應該也辦不到
M24往北方依序可見M18,M17,M16
往西南方可見M8,M20,M21(M23 not far away)
往東南方可見M22(M28 not far away)





主題: 回覆: 沙鹿的星空
作者: yao2013-07-09 15:27:16
往東方可見M25

M24之後向北首先映入眼簾的是
M18:單就M18本身來說是還蠻亮的(至少也知道比8.0等的M26亮了不少)
          不考慮周邊的星星其實也蠻漂亮(M25的周圍有半圈以上的亮星將它包住,很特別)
        The cluster s reluctance to fully resolve into diamond specks would be in vain through small       scopes at medium power,at lease it is what I thought following my initial and repeat but not so serious obervation.

M17:The famous swan-shaped/check mark asterim is hard or next to impossible to tell.Larger in   comparison to M16 and in particular M18.Smaller in area,it to a great extend more than make up this by furnishing us the higher surface bright than M8.The 惠更斯 area in the heart of the M42 is ever
 higher than it .It is almost safe to say it is the second highest surface brightness diffuse nebulae,trailing by M8.I have in hand several LP filters,excluding H-alpha,which seems promsing to this to say the least.
Condensation to SW,bright and odinarlily bight regions easilly distingushed.Nebulae easily seem.
Hard to tell its indivisual members???I guess not.
下次我拿光害濾鏡試看看(Oiii pits sagainst UHC)
以後有機會仔細看看能否以肉眼直接看到M17(M8光其中的疏散星團應該就比M17亮)

M16:Judging from data accquire,all I perseived is nothing but open cluster embedded in nebulosity.
The open cluster is, howeer,still more than worth being looked at.
Not easy to see its indivisual members???I guess not.




     
   


主題: 回覆: 沙鹿的星空
作者: yao2013-07-16 06:34:26
M25,M8,M20,M21,M23 (I will find some time to describe them)

22x70 teams up with/in conjunction to 22x60

第一組
天蠍座NGC 6638 非常易見(sizeable,graddually brighting towards the center)
相比天蠍座NGC 6541 未看但因該只遜半籌

第二組
天蠍座NGC 6281 非常易見(about exactly a  dozen stars not hard to be seen,lacks rest of background stars,not sure if  sighs of  background grow or not)
相比天蠍座NGC 6242  易見 略遜一籌(maybe the same size as M26,not round,rectangular in shape)
天蠍座NGC 6231  北半天球珠寶盒 the northern gewlery box imcrediabe/marvelous/fabulous/unmatched
but sometimes stars too bright to my taste
天蠍座Cr 316 imcrediabe/marvelous/fabulous/unmatched in another fashion,struts its unmourous 10th-magnitude stars,must be larger than 1 degree, 1.5 degree reasonable)

第三組
M19 next time I will look for its oblate shape(of all messier gloublars)
NGC6293 surely be detected halh of,if not most of duration,locationeasily confirmed
NGC6284 border on invisibilty,seems further more precise location will fish it out

第四組
M9 harder to notice than M19
MGC6356 a lot like NGC6293(surely be detected halh of,if not most of duration,locationeasily confirmed)
NGC6342 same as NGC6284,maybe harder than NGC6284,needs better sky or more work

more on Scorpious..........



主題: 回覆: 沙鹿的星空
作者: 星空旅者2013-07-16 09:40:50
你的手真穩,我用12x50就已經不太能接受了~~~


主題: 回覆: 沙鹿的星空
作者: Zoar Chuang2013-07-16 10:01:00
一起來挑戰梅西爾馬拉松吧~
 ;D


主題: 回覆: 沙鹿的星空
作者: yao2013-08-11 17:32:53
先跳tone一下至M33

前兩天半夜在自家透天頂樓看仙后座;M31/32/110;M33等星體
其中M33由三角座西南角的阿法主星向西掃約2度可見兩顆亮星
再由兩顆亮星向西北西掃約2度可見一菱形的4顆亮星邊長約一度多(比兩顆亮星約暗1至2等)
這4顆亮星北方頂點的那一顆較其它4顆約暗一個星等

在這4顆亮星之中
已不只是隱約可見一團霧氣
霧氣真的有一直超過滿月的大小
雖然很久沒拿22X70看滿月的大小
但霧氣真的有一直有接近這4顆亮星圍成的一半面積
反正只比M31小
單位面積亮度可能只有M31核心的1/4
但單位面積亮度可能有M31邊緣的2至3倍

M33 is definetly seen as moderately bright, but is so gauged as it is as high as +70 degrees and more.

偶爾可見似乎東南還是西南邊較亮
反復看了約10次
一次約1至5分鐘
每次都可見M33

M33在沙鹿真的滿令人驚豔的 :o


主題: 回覆: 沙鹿的星空
作者: yao2013-09-18 16:40:27
上個月左右看的幾個天體

M15:以飛馬座epsilion為起點很容易找,而且很容易看到東邊有一顆6等星.屬於較亮的球狀星團,視直徑也較大.

        M15中間有一個行星狀星雲需要大口徑才能看出來

M2:這個球狀星團還是以飛馬座epsilion為起點才比較容易找
       飛馬座epsilion為起點往南35度可見三顆(5至6等星)飛馬座3,4,7呈等腰三角型
       飛馬座3,4,7往南4度可見兩顆(5至6等星)寶瓶座25,26
      寶瓶座25,26為基線往南南西2度可見M2
     
     不建議由寶瓶座beta出發來找
     
      M2約65等整個星團比亮度相近的M15小的多
      也因此變成一個小而亮的球狀星團
      以球狀星團而言單位面積亮度非常非常的亮
      比M15好看

M30:在視野3度的22x70中很容易看到一圈魔羯座亮星33,35,36,zeta....
        From there sweep your field toward 3 degrees ESE, M30 is cuddled by a 6th magnitude star   
         Capricornus 41 0.? degree to the east.
        在夏季銀河之射手座M8可略見的晚上
          M30呈現出非常明確的中心區與邊緣區
          中心區直徑約M30的12至13
        邊緣區直徑約M30的12至23
        中心區亮度surface brightness per aera約為邊緣區2倍至3倍
          非常的超寫實
          比M2還好看
          但只要沒有這麼理想的條件下只見的一個mill-of-the-run球狀星團m30


主題: 回覆: 沙鹿的星空
作者: yao2013-09-18 16:44:25
更正: 中心區直徑約M30的1/2至1/3
        邊緣區直徑約M30的1/2至2/3


主題: 回覆: 沙鹿的星空
作者: 曹大貓咪2013-09-18 18:24:56
下次若看完整個梅西爾可以出本小冊,給大家福利!


主題: 回覆: 沙鹿的星空
作者: yao2013-10-23 17:31:12
補充資料/最近自己巡天時找到的(拿22X70去看很好看的兩個asterim)
1 equilateral triangle asterim
   在M11正南邊1.5度處有一個正三角形(約18h51m -7.50degree)
   相似度95/100至100/100
2 arrowhead with arrow shaft asterim
   另一個很像箭簇及箭桿的星星集合好像在寶瓶座(下次在仔細看看到底在那裡)
   相似度90/100
   拿22X70自己去找看看特殊asterism是很有趣的


主題: 回覆: 沙鹿的星空
作者: peter2013-10-23 18:09:41
M11
http://familystar.org.tw/index.php?option=com_smf&Itemid=45&topic=20005.0



主題: 回覆: 沙鹿的星空
作者: yao2013-10-24 16:29:23
仙后座疏散星團
1 NGC7789(white rose cluster)
   易找度 8.5/10
   觀測易難度  6/10至8/10
   可看度 7.5/10;暗空下8.5/10;.大口徑加暗空9.5/10(例如12吋可見1000顆星,8吋可見300顆星)
    這個疏散星團受光害影響程度滿大的.NGC7789可以從微微可見至unmistakenable/third of the Moon   diameter
   至於其中星星是完全無法分解
    由於我這裏北天極附近光害較重,之前在大雪山13公里處的7789是好看多了.
    7789是北半球觀測者前10名好看的疏散星團(通常排在M35,M36,M37,M38之後)
  
2 NGC129
   易找度 8.5/10
   觀測易難度  6/10
   可看度 7.5/10
   會有些微的不確定看到性.微微的光.星團可持續分解3顆星.視直徑約M26或稍大於M26.絕對比M26暗(面積大加光害重)

3 NGC225
   易找度 8.5/10
   觀測易難度  6/10
   可看度 7.5/10
   會有些微的不確定看到性.微微的光.星團不可分解星星.視直徑約與NGC129相當. 看久了比較容易看出是疏散星團.

4 NGC457(owl cluster)
  易找度 7/10(真的有一定以上找不到的機律)
  觀測易難度  9/10
  可看度 8至9/10(條件稍差時8/10)
  這個星團稱為owl cluster,ET cluster不過我個人感覺應稱它是鬼雙子座星團ghost of Gemini
  把貓頭鷹和ET的詭異加上雙子座的輪廓(頭手腳腰都有)想像在一起
   比較不像ET
  如果條件很好時頭手腳腰不會很費力的觀測出來
   貓頭鷹的兩顆一藍一橘的眼睛太好看了
   絕對是22x60這種雙筒的showpiece

5 M103
  易找度 9/10
  觀測易難度  8/10
  可看度 8/10
  雖然說亮,但只分解出幾顆亮星.但是觀測條件變好時視直徑感覺有大上一倍,這時有八成的可看度.

6 NGC663
  易找度8.5/10
  觀測易難度  8/10
  可看度 8.5/10
  Cladwell Object其中之一,最少可分解接近十顆星,未分解的疏散星團的背景還不錯
   真的蠻好看的疏散星團(但有輸NGC457)
   22x60不知能否分解20顆以上星星(沙鹿或大雪山)??????????

7 M52未看

 


  


主題: 回覆: 沙鹿的星空
作者: yao2013-12-02 10:15:19
補充資料/最近自己巡天時找到的(拿22X60去看很好看的一個asterism)
3 Grand Pusedo-Christmas Tree asterism 大(偽)聖誕樹星團
   船尾座zeta北北東方5度處有一個正三角形(約centered at 8h15m -35.9degree)
   
   好找度90/100  目標離超亮的船尾座zeta不遠+離4等亮的船尾座q更近+NGC2546可幫助定位
   相似度85/100至95/100  把亮星船尾座q弄到視野之外就至少90/100 相似
   可看性95/100  都已經標示Grand了
    特徵
    適合倍率30倍以下(另外用50度以下窄角目鏡觀測把亮星船尾座q弄到視野之外比較像 ^-^也比較好看  ^-^)
   右下方(正向)或樹的西南方有兩組交會的一對亮星(2x2=4),左上方亮星為船尾座os,這4顆亮星把它想成裝飾品吧 :P
   樹的上方一顆星私儗為避雷針(約centered at 8h14m -35.2degree)  :P
   其他
    NGC2546(視直徑約40秒)用22X60至少有十幾顆9等星可見-*不過沒特別注意它就是了


主題: 回覆: 沙鹿的星空
作者: yao2013-12-27 21:07:25
前幾個星期用22x60掃過一次M48

哇,沒想到M48星星數(沒仔細數;約50 plus;易見;亮度平均;無集中)竟然有可能比M35多(但極有可能M35星星數比較多)
另外,M48也比想像中的好看(如天使塵/angel dust)
看完後還滿high的 :P

PS:之前的有一些要補充;有一些要修正
PS:其餘觀測近期補充



主題: 回覆: 沙鹿的星空
作者: yao2013-12-27 21:49:39
目前的目鏡

X4
Takahashi Le 30mm
Takahashi Le 18mm

X3
Meade Swa 4000  13.8mm

x2
Vixen Lvw 22mm
Vixen Lvw 17mm
Vixen Lvw 13mm
Vixen Lvw 5mm
Vixen Zoom 24-8mm
Meade Swa 4000 18mm
Celestron Plossl 10mm
Tmb PlanetaryII 8mm
Orion expansa 9mm

X1(2 inch)
Tele Vue Plossl 56mm
Willam Optics Swan 40mm
Willam Optics/Olivon/Santa Let  35mm
Kuming Optics/Sky Rover Swa 28mm
Agena Astro Swa/Sky Rover 26mm
Willam Optics projection eyepiece 18mm

X1(1.25 inch)
Howa Plossl 35mm
Celestron Plossl/Vixen Plossl 26mm
Howa Plossl 25mm
Zumhill Ler 12.5mm
Celestron W.A 10mm
GSO Plossl 9mm
Zumhill Ler 9mm
Tmb PlanetaryII 9mm
Howa Plossl  7.5mm
Zumhill Ler 6mm
Zumhill Ler 3mm

憑記憶,應該沒有漏掉
 


主題: 回覆: 沙鹿的星空
作者: yao2013-12-27 22:03:06
漏了x1
Orion Epic ED 12.5mm

coming soon
Wide Scan III 30mm 82 degrees

Most wanted(in decending order)
Vixen Lvw 8 mm x2
Pentax XW 10 mm x2
Takahashi 12.5mm x2
Paradigm 12mm x2
Stering plossl 12.5mm x3
Stering plossl 25mm x2
Sky Rover extra flat 19mm x2
Willam optics/Sky Rover  Swa 20mm
Swa 20mm或12.5mm 十字線目鏡



主題: 回覆: 沙鹿的星空
作者: yao2013-12-27 22:11:31
漏了x1 Meade Uwa 4000 4.7mm

還缺行星專用目鏡與超超廣角目鏡(的錢 :'()


主題: 回覆: 沙鹿的星空
作者: BX4AAW2013-12-27 23:10:21
姚兄,這麼拼命,超級寒流你還到陽台看星星喔 ? :o :o :o


主題: 回覆: 沙鹿的星空
作者: 威信老萬2013-12-28 00:14:38
漏了x1 Meade Uwa 4000 4.7mm

還缺行星專用目鏡與超超廣角目鏡(的錢 :'()
你不是欠一顆Wide Scan III 30mm 82 degrees?
下面的這顆,要不要考慮一下?聽說還在國外得過獎,C/P值很高。我正要考慮敗下去,是否有興趣一起買?
智通80度廣角2寸F30mm天文望遠鏡目鏡2寸目鏡
http://item.taobao.com/item.htm?spm=a230r.1.14.54.xSURon&id=35570676886


主題: 回覆: 沙鹿的星空
作者: yao2013-12-28 14:30:22
老萬兄您好

Wide Scan III 30mm 82 degrees是有同好賣我(周邊修正不好,以後大部份時間會用在大於F10的鏡筒)
關於智通80度廣角2寸F30mm天文望遠鏡目鏡2寸目鏡
好像它的80度廣角2寸F20mm天文望遠鏡目鏡2寸目鏡
其實是80度廣角2寸F30mm+1.5倍巴羅鏡組合而成
所以買80度廣角2寸F20mm會更有利些(Killing two birds with one stone,so to speak) :-*

好像此系列的11mm出瞳距離太低,視野近似於plossl(去掉eye guard帶眼鏡觀測仍會刮到眼鏡)

如果是Willam Optics Swan系列33mm表現有比較突出(f6 ok)
如果是裕眾Swa系列(Agena Astro Swa)32mm表現有比較突出(依序為32mm,38mm,26mm)

再高一級有裕眾另一Swa系列(Tmb Paragon/Astro tech Titan II)

您大概參考一下




主題: 回覆: 沙鹿的星空
作者: yao2013-12-28 14:48:55
裕眾(Tmb Paragon/Astro tech Titan II)再高一級還有Meade Series 5000 Swa,Explore Scienctific Swa

智通11mm可能視野也可能可以到70度左右(不確定,也許視野近似於plossl?)


主題: 回覆: 沙鹿的星空
作者: 威信老萬2014-01-02 07:30:22
Dear yao:
早安!由你的回覆中,你似乎用過智通的目鏡?我用上2吋目鏡的理由很簡單,是進行目視觀測時,能獲得視野廣,亮度高的環境。現在比較擔憂是,廣視野2吋長焦距目鏡,用在20公分F4牛頓反射上,視野中心會出現黑影,周邊星點會嚴重變形。


主題: 回覆: 沙鹿的星空
作者: yao2014-01-03 08:00:31
老萬兄您好

這隻不適合用30mm

1 年紀越大出瞳超過7/8/9的機率越低=浪費倍率

2 背景太亮=降低對比

3 用有副鏡折反射時=目鏡出瞳孔與黑影遮避率成正比
    尤其大遮避率副鏡之折反射 (估計0.25遮避率之牛頓F15經典卡賽格林F20馬卡;020遮避率之馬牛很難成為問  題), 目鏡出瞳孔太大時黑影非常嚴重
    In this case
    目鏡出瞳孔為30mm除以4=7.5
   假設人眼出瞳5;副鏡遮避率0.33
   黑影遮避率為7.5除以5乘以0.33等於0.495
    假設人眼出瞳7.5副鏡遮避率0.4
   黑影遮避率為7.5除以7.5乘以0.4等於0.4
   解決方法1換鏡筒 2換數字低目鏡焦距

4 (尤其F5以下)未裝慧星像差修正鏡或目鏡設計周邊修正不夠=周邊星點會嚴重變形
   前者解決慧星像差
   後者解決慧星像差以外的像差
   Wide Scan III 30mm 82 degrees周邊修正不夠可能要F12左右才適合

5 超廣角低倍率比超廣角高倍率更易周邊星點會嚴重變形=需要修正好一點的目鏡
   
   
   
   


主題: 回覆: 沙鹿的星空
作者: yao2014-01-03 08:37:08
老萬兄您好

先自己量看看眼睛出瞳最大是多少吧

一般來說,關於好一點的1.25吋目鏡24mm/68度視野是很好的選擇
但問題大陸與台灣比美國的賣價貴太多了

Meade S5000 24mm是很好的選擇
戴眼鏡也可以見到68度視野(Meade S5000 16mm,not so much)
修正也極接近Tele Vue
周邊枕狀像差無可人肉go to/push to/star hop(Tele Vue,no)
ES 24mm/68度差在戴眼鏡較不舒適一點

不過f4的要求太高
比較接近完美修正的是Tele Vue Panoptic/Delos/Ethos/Most of Nagler;Vixen LVW
估計以下修正方面仍然差了些許(差距不多但仍然有)Pentax XW/XL;Denkmier 14mm/21mm;Meade S5000 UWA/SWA;Meade S4000 UWA;Celestron Axiom

這些目鏡中挑便宜的買吧(真的有錢還不如買ES系列100度/120度視野目鏡)




主題: 回覆: 沙鹿的星空
作者: yao2014-01-03 09:30:46
以下憑記憶(難免疏漏)

Perseus

M34  rather easily be found;bright, on the other hand too bright and a little too sparse makes for a slightly dull scene;forget how  much dim stars can be pushed to resolve or glow ones can be seened with ease

NGC1245 

NGC 1545 worth observing;smaller than 1528;not overly impressed with but not disappionted with,either;noted for one blue,one white,one orange star(try as I might,I could not distinguish its tint);all but these three or four stars stands out(kind of)against the backgroung mist(sort of).

NGC1528  lovely;defintely spotlight of NGC1545/NGC1528 pair;overshadowing NGC1545 in beauty;(should I say rare )a sight in Perseus;uniform in brightness(bar one or a few?)

NGC1545/NGC1528 will fit in all but the larger magnification Binoculars

NGC1582 four or so speck of light detected;ghostly but large glow;forget which is more easily seen,1664 or 1582,maybe 1582;rewarded with patince,practice,reduced pollution of light.





主題: 回覆: 沙鹿的星空
作者: yao2014-01-03 10:08:47
以下憑記憶(難免疏漏)

御夫座(以下疏散星團在微微微亮的銀河背景下相當不錯;not NGC1664)
NGC1664  NGC1582正東方約三度(或御夫座西方約1.5度),好像處於可見不可見之中(同志仍須努力 :P)

NGC1857 少提到的星團星團;範圍內南方有幾顆亮星與其他範圍內暗星或背景星成對比;約解出10顆星(?);不太大也不小;夠亮;推薦很不錯的星團

NGC1907/M38  記憶中M38可分解50顆星;與南邊的NGC1907一起看真的很漂亮;單獨看NGC1907本身也夠亮/夠大/夠漂亮/亮度平均;用望遠鏡看NGC1907應相當美

M36

M37

Stock 10 記得有看過?相當的ok的星團

NGC 1931 暗空的挑戰

IC 417 暗空的巨大挑戰;應該比NGC 281 pacman難


主題: 回覆: 沙鹿的星空
作者: yao2014-02-20 14:45:22
Intes MK66憑記憶之其中一部份(難免疏漏)

M35 很像pussy ;D;也很像dick ;D

NGC2158 6至10顆亮星似W型

NGC2157 高倍星點較高倍NGC2158多

只有NGC2157使用高倍觀測的差異性較大


主題: 回覆: 沙鹿的星空
作者: yao2014-02-20 15:10:38
船尾座zeta附近4大天王只要有微微銀河出現就很好看

工具:22x60

Grand Pusedo-Christmas Tree asterism
NGC2546(the best)(numerous stars-at least 30,pherhaps up to 60 or 70)
NGC2451 星團中心4等星船尾座c深橘色星很特出 :P;星團所有亮星用22x60即可看出
NGC2477 coming fleetingly in and out of the threashold of detection
                偶爾能確定是一個大的星團;如果延長觀測的時間和次數就能確定自己沒有看錯
                    此星團受光害影響很大
                    多年前在大雪山13處觀測(民宿群聚營業前 :'();記憶中比NGC2451還好看
                    NGC2477應該是絕對排名在南天球前20名的疏散星團(其實NGC2451也是:但我覺得NGC2546更好看)




主題: 回覆: 沙鹿的星空
作者: yao2014-02-21 15:12:08
過年時入手三顆目鏡
(0.98 plus light trasmission)
x2 sterling plossl 25mm
x1 sterling plossl 12.5mm

太晚去了,25mm只剩2顆展示品
老闆特地拿眼鏡布搽
不好,店面靠近馬路所以目鏡與眼鏡布灰塵多擦花了 :'(

注意:沙塵暴的灰塵更可怕,數年前好好的一副玻璃眼鏡只擦了那一次就快爛掉了

sterling plossl 12.5mm只買到2個之中的1個
無法做binoviewer的目鏡組

12.5mm初步觀測月面相當ok
eye relief=12.5x0.6=7.5裸視剛好
eye relief較一般plossl短
no major ill optical effects detected

心得 :sterling plossl 25mm也許可以是窮人的Takahashi le 25mm
          sterling plossl 12.5mm也許可以是窮人的Takahashi le 12.5mm
          Tmb planetary for 9mm and below(apov 58degrees)
        Sterling plossl  for 12.5mm and up(apov 55degrees yet more like 58degrees)




主題: 回覆: 沙鹿的星空
作者: yao2014-03-01 16:53:30
最近拿22x60出來看月亮發現

1 比想像中可辨識的月坑還多
2 第谷/哥白尼附近的放射條紋數量比15公分的折反射容易看出來;放射條紋的顏色對比也較明顯&好看(普羅克呂斯/刻卜勒周圍放射也很好看).
3 月海可能接近百分之百都可以辨識;顏色對比也較明顯&好看.
4 直壁(straight wall)這種山脈也滿明顯的
注:大月坑內的山或大月坑內的小月坑不知能否分解(要拿穩定一些的腳架與更多的測試才會有答案)(the jury is still out: number1)


主題: 回覆: 沙鹿的星空
作者: yao2014-05-23 17:30:59
這2個月的目鏡變化

讓出3隻
takahashi le 30mm x2
(手上仍有takahashi le 30mm x2)

vixen lvw 17mm x1
(手上仍有vixen lvw 17mm x1)

入手
tmb planetary 4mm x1
badder hyperion 24mm x1
meade s5000 swa 24mm x1



主題: 回覆: 沙鹿的星空
作者: yao2014-10-24 11:24:41
M8正下方4度的疏散星團NGC6520只要天氣不要太差是22X60很容易看到的目標

不知道旁邊的dark nebula B86是否光害少的地方可以看見???



主題: 回覆: 沙鹿的星空
作者: peter2014-10-24 13:16:49
明天是 star party 可以來翠峰停車場看看


主題: 回覆: 沙鹿的星空
作者: yao2014-11-09 20:46:12
最近用了2次orion expansa 9mm同款目鏡看月面

感覺如下
resolution/contrast/shapness  ok
lateral color  none or vey little
glare medium(maybe a little more or a little less)
blackout  4-5/10
kindney bean  7-8/10
最大缺點是kindney bean明顯較其他款目鏡重 :'(
不過以130人民幣以下的售價來說
沒有什麼好挑剔的 :)

ps1 款目鏡看月面沒問題;但聽說orion expansa 6mm炫光較重
ps2 orion expansa 9mm其實是8.6mm
ps3 觀星會有位Vincent Chou也有用過orion expansa 9mm
ps4 cloudynights Issac Jon認為它是窮人的Nagler 9mm t6(再買9mm t6之前用orion expansa 9mm於低焦比牛頓感覺很滿意)
 



主題: 回覆: 沙鹿的星空
作者: yao2014-11-10 18:30:58
稍微修改一下關於orion expansa 9mm如下

使用器材 Intes MK66
blackout  4/10
kindney bean  6/10至7/10


主題: 回覆: 沙鹿的星空
作者: yao2014-11-10 19:03:02
簡述關於景得雙眼目視裝置

數年前購入景得雙眼目視裝置,到貨後小心翼翼的稍微拿來看白天的風景(使用10mm f10 refractor+takahashi 30mmx2 and 18mmx2),光軸很正且效果不差.數年後確出現光軸大偏差.前幾個月詢問景得小姐,要求把雙眼目視裝置圖片及購買或出貨證明圖片兩者傳給她才能確定把物品後續交給景得處理.(我目前電腦或攝影機有問題無法把圖片傳給她,所以無法後續處理..........) :-[

所以之前大陸有同好賣二手類似景得雙眼目視裝置,怕光軸不好處理便沒有下手. :(

不過已與一位同好說好明年寒假或暑假接手他一只badder zeiss mark v目視裝置(左眼或右眼微霉), 效果應該不錯:D




主題: 回覆: 沙鹿的星空
作者: yao2014-11-19 21:11:08
之前在天文看到有人在中央公園用22x60看完全部梅西爾天體,哇 :o :o :o


主題: 回覆: 沙鹿的星空
作者: yao2014-11-19 22:14:48
之前在天文家園看到有人在中央公園用22x60看完全部梅西爾天體,哇 :o :o :o


主題: 回覆: 沙鹿的星空
作者: yao2014-11-20 18:25:00
政府兩年內全面汰舊水銀燈換新LED燈,是否意味手上的deep sky filter將無用武之地?? :' :'(((deep sky filter好像把鈉線sodium給block掉).


主題: 回覆: 沙鹿的星空
作者: yao2014-11-20 18:30:39
昨天二手信達ED120 pro-series從廈門寄到沙鹿(尚未開光 )::)請各位猜猜價錢.


主題: 回覆: 沙鹿的星空
作者: yao2014-11-23 11:03:01
前天小測試二手信達ED120 pro-series先找出幾個缺點
1 對焦座稍微講究的話,未來仍然需要升級(所附對焦座加2吋目鏡會wobble/flexture)
2 天狼星100倍非純白色會有紫色
3 與intes mk66相比鏡筒較長架於經緯儀上較易搖晃及觀測姿勢較差
相信其他沒什麼問題 8)期待ED120 pro-series於行星上的表現 ;)


主題: 回覆: 沙鹿的星空
作者: yao2014-11-23 11:22:45
有次去大雪山川棟林道時遇見之前在大雪山開過民宿高濱小築的陳高濱先生 :D,大雪山土地他很熟的(有人想在大雪山買塊地看星星的嗎????)


主題: 回覆: 沙鹿的星空
作者: yao2014-11-29 10:28:40
下星期1將中古intes mk66以破盤價台幣8000元運至上海,I miss you,baby.(oh,baby I love your way,everyday.............. :'()


主題: 回覆: 沙鹿的星空
作者: yao2014-11-29 15:55:29
記憶中M22旁的球狀星團ngc6638用22X60易見.
在沙鹿須要很好的透明度才行.
M28旁的球狀星團ngc6642用22X60不那麼確定;但參考資料後應該到暗空區有辦法.
也就是ngc6642比ngc6638稍難些.


主題: 回覆: 沙鹿的星空
作者: yao2014-11-29 16:11:22
Acton,baby.
原來binocular telescope有這種缺陷 :(
These BTs don't have a large focus range so the location of the field stop relative to the shoulder of the eyepiece is very important. (cloudynights  Kunming United Optics 45-deg, 100mm Semi-Apo triplet -- questions and eyepiece suggestions  by Rich V.)


主題: 回覆: 沙鹿的星空
作者: yao2014-11-29 16:14:35
一般交換目鏡雙筒也有這種缺陷 :(


主題: 回覆: 沙鹿的星空
作者: yao2014-12-01 19:03:13
目前手上的光害濾鏡(幾乎皆1.25吋的)

Lumincon deep sky              x1
Lumincon oIII                       x1
Lumincon uhc                       x1
meade     oIII                       x1
meade     narrowband          x1
meade     narrowband          x1(for sct opening)
badder     moon&sky grow   x1
badder     moon&sky grow   x1(2 inch)
杭澄         dark sky d type     x1
杭澄         oII                        x1
杭澄         uhc(oIII/h beta)    x1

各位若有2吋目視用光害濾鏡要賣或交換1.25吋的光害濾鏡請聯絡我 :)


主題: 回覆: 沙鹿的星空
作者: yao2014-12-01 19:06:21
目前手上的光害濾鏡(幾乎皆1.25吋的)

Lumincon deep sky              x1
Lumincon oIII                       x2
Lumincon uhc                       x1
meade     oIII                       x1
meade     narrowband          x1
meade     narrowband          x1(for sct opening)
badder     moon&sky grow   x1
badder     moon&sky grow   x1(2 inch)
杭澄         dark sky d type     x1
杭澄         oII                        x1
杭澄         uhc(oIII/h beta)    x1

各位若有2吋目視用光害濾鏡要賣或交換1.25吋的光害濾鏡請聯絡我  :)


主題: 回覆: 沙鹿的星空
作者: yao2014-12-05 19:45:57
一般交換目鏡雙筒可以左右兩邊用不同焦距目鏡,其中一個目鏡須用parforcal ring此時可同時得到左右兩邊不同倍率 :P(也許一邊是尋星,一邊是closer look).


主題: 回覆: 沙鹿的星空
作者: 伴儂2014-12-05 20:47:12
一般交換目鏡雙筒可以左右兩邊用不同焦距目鏡,其中一個目鏡須用parforcal ring此時可同時得到左右兩邊不同倍率 :P(也許一邊是尋星,一邊是closer look).

.....這樣用.看完後.眼睛會不會變成鬥雞眼? :P


主題: 回覆: 沙鹿的星空
作者: yao2014-12-06 15:02:30
我話沒有說清楚 :-[
one option:先一邊是尋星,再另一邊是closer look,最後再把尋星那邊的目鏡換成另一邊closer look高倍一樣的目鏡. ;D
the other option:先一邊是尋星,再另一邊是closer look隨時做單眼不同倍率的切換. ;D

類似的道理是用兩個相同焦段的目鏡,只將其中一個加上目視光害濾鏡隨時做with&without目視光害濾鏡觀測的切換. ;D ;D



主題: 回覆: 沙鹿的星空
作者: yao2014-12-17 19:12:07
不知道1.25英吋濾鏡用於8x30鏡子前效果如何??


主題: 回覆: 沙鹿的星空
作者: yao2014-12-17 22:03:38
20年計劃之鏡32x82 vs 40x80

之所以是40X 80mm 的雙筒,理由是某同好看過32x82 pronomier後不滿意,
而且對他來說直視型看白天更有利.

對我來說反覆考慮40X 80mm與32x82 之後選擇40X 80mm
最最主要原因是經濟上可以接手撿個某同好二手的
其次是似乎直視型對目標比較容易(應比22x60稍難)
再其次是未來老的時候有計劃所有直視型都會變成躺在椅子上看
其四是40X 80mm較輕,似乎比32x82容易帶上鳶嘴山這類的地方(希望到時老而彌堅)
其五是40X 80mm對大部份在沙鹿觀測疏散星團與球狀星團的我來說更加有吸引力
(尤其對我40X 80mm比32x82更有興趣觀測人馬天蠍球狀星團-倍率高些)
其六是40X 80mm的那對12.5mm目鏡未來有可能會利用到
其七是口徑與倍率配置的關係40倍似乎較好用.目前手上及計劃的主力除高橋22x60與富士10x50外, 依序是8x30/12x50/20x80=19x76??/28x110,40X 80mm的2釐米出瞳有時若不好用未來40倍時會動用可變倍率的4釐米出瞳40x150普消或半消或全消雙筒
其八是未來用濾鏡時會動用40x150普消或半消或全消雙筒,其餘除5公分口徑的鏡前裝濾鏡雙筒外不太會考慮用濾鏡於雙筒上
其九是22x60與32x82與40x80的實視野三者都差不多2.2度,選40x80似乎並無不可(極窄角與極廣角afov之比應該很有趣)

目前手上考量的基準是22x60與一系列4釐米出瞳的雙筒,稍微有可能會入到5.6出瞳的雙筒(10x56/20x110),也可以說是根據光學表現(22x60)與觀測環境(沙鹿)與未來老年出瞳(不超過5.6出瞳以4釐米出瞳為主力)三方面的綜合考量


主題: 回覆: 沙鹿的星空
作者: yao2015-06-03 17:48:53
1 最近新出的新一代裕眾旗雲雙筒(紅圈)似乎有帶平場鏡設計???

2 這個暑假apm即將推出窮人的TEC 140 apo................APM 140 F7 doublet apo :)
    the secondary spectrum is corrected to the level of 1/13200 of the focal length ( for F/C/E)
   The Polystrehl is 91.7 %
   
   observing length should be 1000 mm = 39.4 inch
   transporting length should be 800 mm = 31.5 inch

  鏡片  O Lanthanum Crown+FPL53
 (our mating element is a Lanthanum Crown glas and it is one of the best matches found)
 
  6-7kg(between 13.2 lbs and 15.4 lbs about)

 price:usd 3000


主題: 回覆: 沙鹿的星空
作者: yao2017-09-04 15:03:49
22x60手持需要背靠/手軸撐牆/頭靠枕頭/或直接全身躺在地上
如果平常都不是用廣角目鏡看星的話視野幾乎完全沒有問題
如果平常都是用廣角目鏡看星的話的確會覺得視野小了一點
不過這隻算是找目標(2.2度)和觀測一體(22倍)的雙筒
這種組合很特別
對天空夠熟的話22x60本身不需要加尋星鏡或紅點
如果比較靠近台中的話
可以到我這裡看看
測試覺得不錯的話就可以和福聲買下了

2.2度視野得雙筒有28110(2.3度)/tak22x60 apo/kowa 32x82 apo/docter 40x80 edapo
這幾隻都很好
唯一要注意28110非edapo,很重,光軸也比較容易偏

22x60天氣比較好時我在沙鹿這裡看
m24應該超過100顆星
m48應該超過80顆星  不然至少也有50顆星
m35+ngc2158+ngc2157都看的到
....................
22x60上山應該也比2080稍好些(尤其星點超過3倍以上的細)
22x60實際上集光力不比wo2270差
上山2080最佳狀態可以看到m83兩條懸臂
但是2080或是wo2270 apm1670 nikon1870......都比這隻重
手持都比較累......尤其wo2270

22x60的低倍輔助鏡
無疑是swarvoski 15x56 slc wb

當然有錢一些的可以用swarvoski 15x56 slc wb
預算緊一些的可以用apm1670 ed藍圈
預算更緊一些的可以用apm1670 紅圈(目前我沒有apm1670 ed藍圈)
破除品牌情節的話光apm1670 紅圈就應該會比fuji 1670好(fuji 1670我沒用過)












主題: 回覆: 沙鹿的星空
作者: yao2017-09-04 15:14:09
tak 22x60/wo 22x70/swarvoski 15x56這三隻雙眼都可以矯正至600度以上沒問題 :D
以上三隻swarvoski 15x56能超過600度以上的幅度比較小 :(
另外一隻nikon 18x70似乎只能矯正至500度,但600度似乎不行,很少用,還要再測
判斷的標準是自己舊的眼鏡500度左右+還是看不清很多東西+開始嚴重的飛蚊症 :'(


主題: 回覆: 沙鹿的星空
作者: yao2017-09-20 16:35:27
確定nikon 18x70只能矯正至500度
不能至600度 :'(

tak 22x60/wo 22x70/swarvoski 15x56/apm 16x70/vixen 20x80這五隻雙眼都可以矯正至600度 :D
(vixen 20x80沒拿出來, 但估計是可以, 沒問題)


主題: 回覆: 沙鹿的星空
作者: yao2017-09-20 16:56:40
上個禮拜拿tak 22x60看m31這一區
m31核心很清楚 ,無細節, 長軸不足1度??
m32呈圓形 ,核心很清楚, 單位面積亮度至少是核心2倍,無誤, 說有4倍也不過份(說有4倍這部分可能稍微稍微......主觀些)
m32呈核心+外圍呈圓形, 大小比m28大些,無誤
ngc206是個挑戰, ngc206應該比m110與m31外圍容易些,未拿星圖對位置, 不過離m32很近, 位置不容易搞錯,應該有看到但不能確定,
比m32外圍還要暗, 均質, 應該大小和m32差不多,應該有顯現些許扁平,還要再確定(尤其是應該的部分)


主題: 回覆: 沙鹿的星空
作者: yao2017-09-26 12:58:12
轉貼一下 :P

致各位天文爱好者: 我们公司为专业制造天文望远镜的生产厂家,尤其擅长复消色差的生产和加工,有多年的加工经验,也为很多的厂家做贴牌组装。以及系统的配置,为了迎合大家的需求,先对广大的爱好者定制一批复消色差的天文望远镜镜片及含框装配,由于考虑大家的各种需求,我们特选三个规格的型号可供选择定制:1、口径160三片式,单价为31000元每套,十套以内的价格为26000元(含框及物镜装配);2、口径180三片式,单价为41000元每套,十套以内的价格为36000元(含框及物镜装配);3、口径203三片式,单价为51500元每套,十套以内的价格为46500元(含框及物镜装配), 口径为上诉三款,焦比暂定在F6.5-F7.5之间,为三片的APO,采用国内的FK61材料,匹配另外两种国产材料,经过二次槽成加工和精密退火,达到理想的复消色差的效果,加工我们也是有经验的老师傅加工,毕竟我们出口加工过两片式的口径314的经验,镜片的检验我们结合做人工星点检测,配合朗齐光栅做球差校正。也可委外抽检做干涉仪报告。 本次感谢各位的信任,由于前期投入成本开发费用比较高,所以采用众筹的形式,一方面更大程度的让利给各位,另一方面也缓解我们厂家的资金压力,接受预定的,任一款满足十套及时开工,预付50%作为定金,周期暂定6个月,款到发货。 再次感谢各位的信任和支持,本公司不遗余力,为各位效劳。 淮安市岽盛光电仪器有限公司 朱爱军 15861791218


主題: 回覆: 沙鹿的星空
作者: yao2018-01-14 09:33:17
補紀1: 2017 gemini meteor shower 12/15 00:30左右ngc 2244旁有一顆流星經過,光度比
ngc 2244個別星等大了約2等??但重點是ngc 2244旁有一顆流星經過2080視野時竟然就在旁邊,光度比
ngc 2244總體星等不會差太多,顏色也差不多(所以不會是雙子座流星),路徑長度也不長太多(兩倍吧),
流星與ngc 2244相稱太好看了 :P

補紀2: 2004 1/4左右的池古- 張慧星與卯宿在2080視野內也許更漂亮些



主題: 回覆: 沙鹿的星空
作者: yao2018-01-14 09:53:51
前幾天最冷的時候,透明度很好,確定用1670 ::)手持,可以100%看到m78
方法: 1 躺在睡袋,m78比較接近中天時手持,一手軸可以撐地,另一手軸可以調角度,很穩的 :P
        2 大概知道m78在三星的左上方,左上方那好幾顆6-7等星附近,但是沒有事先查星圖,
           也不必事先查星圖,因為仔細地+慢慢地掃,m78就找的到,找10次至少至少出現9次
        3 找10次至少至少出現9次,所以不難
        4 與m79相比,看得出許多不同點...............
        5 以這個夜晚的情形,旁邊的ngc2071不知道高倍還能手持程度的雙筒(docter 4080....)
           有沒有辦法100%看到


主題: 回覆: 沙鹿的星空
作者: yao2018-01-14 09:59:22
透明度很好的夏天,m57用1870手持(實際上是1770)可以接近100%看到m57成小小圓盤,不是星點

至於1670,1556,我忘記有沒有試過........


主題: 回覆: 沙鹿的星空
作者: yao2018-01-14 10:01:22
lunt 1670最近用的比較多,有人有興趣的話我可以提供一些使用後的感想


主題: 回覆: 沙鹿的星空
作者: yao2018-02-07 09:06:00
我一直覺得東可達應該和某些廠家合作
那些廠家只要能提供拚好鏡筒的服務
鏡筒與(尤其是)調焦大陸source很多
不需要到頂級
其實還是可以造福budget-minded的同好
東可達+某些廠家合作做出來的東西又不會太貴


主題: 回覆: 沙鹿的星空
作者: yao2018-02-07 09:16:35
目前正在看看欲眾會不會出直視型apo 82mm雙筒
直視型apo 82mm雙筒可以天地鳥花用
直視型好處是天地鳥花皆可直覺式的使用

不會像docter 4080那麼貴
色差應該比docter 4080好(其他不知道)
又可以依照自己預算與喜好配目鏡

直視型apo 82mm雙筒手持40x不行的話(躺著手持或背靠手持)
手持32x應該還是可以
cn上有docter 4080不多
其中就有一人手持docter 4080





主題: 回覆: 沙鹿的星空
作者: yao2018-06-06 07:39:51
組裝ed 120mm過程中遇到三個問題

1 收到一只skywatcher ed 120mm黃鑽一代與一只skywatcher 龍鵬ed 120mm
一只, 兩者做工差距甚大, 很想繼續收一只與skywatcher 龍鵬ed 120mm, 只是能否收到還是未知.........
2 skywatcher ed 120mm黃鑽一代鏡筒外鏡比龍鵬小了一號, 總不可能用膠帶纏到與龍鵬相同, 如果兩隻鏡筒大小不一的情況下拼成雙筒結果應該會差一些,而且2047天文工作室可能比較不太願意替我製作雙筒筒箍
3 2047天文工作室似乎做出的雙筒筒箍都是配自家的轉向裝置, 2047有辦法
  給我製作中松本的雙筒筒箍嗎??


主題: 回覆: 沙鹿的星空
作者: yao2018-06-06 07:57:37
唉,關於口徑的升級

If I had knew then what I kown now, 我就不會投資這麼多了 :-[
反正就10/20/40/80一路升級上去絕對不會後悔
不然就7-8/15/30/60.............

唉 :-[





主題: 回覆: 沙鹿的星空
作者: peter2018-06-06 10:32:36
可以買同好  2手


很多人會換



主題: 回覆: 沙鹿的星空
作者: yao2018-10-04 17:33:30
雙筒鏡歷年紀實總匯(1)

1.vixen 20x80可見M101兩條懸臂; 接近中天數小時之中皆不難見兩條懸臂; 大雪山35K處; 當日寒潮爆發有逆溫層所以極晴朗條件極好
2.vixen 20x80可見母子星系; 大約同上(當然無懸臂)
3.vixen 20x80可見M83兩條懸臂;不會很難;大雪山18K處;當日情況還不錯, 趁半夜一點騎車至18K處, 想說這樣night vision會好些(應該沒差).....估計M83的是星等與面積剛好在 20x可見兩條懸臂的下限
PS; M101與M83應該是20X80唯二可見懸臂的星系
4.vixen 20x80可見草帽星系;同上;但暗帶無望見到
5.vixen 20x80可見M68;同上;屬於暗的梅西爾球狀星團.....我在沙鹿用apm 20x70似可見到, 真的不確定
6. vixen 20x80可見NGC6940與NGC3939; 不難, 其中的星系比較難些; 大致可以分辨哪一個是星系, 哪一個是疏散星團,如果有28X110可以看到星系淡淡的懸臂; 大雪山25K處
7.vixen 20x80可見NGC55; 不難,非常大面積, 很被忽視的大面積南天星系, 表面暗淡不至於太暗, 推薦, 不可不看; 大雪山22K處
8,vixen 20x80可見漢堡星系; 簡單,連中間分裂的暗帶也很簡單,很可愛的星系, 暗帶有不規則鋸齒狀需大些口徑與倍率; 大雪山22K處
9, vixen 20x80可見NGC253; 超簡單, A view to die for.....,如果搞個20公分雙筒來看的話如何呢(期待...); 大雪山22K處
10.vixen 20x80可見NGC3115, 簡單,面積雖不大但形狀如其名像紡錘,單位面積超亮,推估就算是市區與郊區處也可以用小口徑看到而且也不會太無趣(也不會太有趣)的星系; 大雪山13K處


主題: 回覆: 沙鹿的星空
作者: yao2018-10-06 08:54:07
雙筒鏡歷年紀實總匯(2)

11. 沙鹿 apm 20x70ed可見NGC253; 晴朗+透明度超級好(空氣指數AQI=19); 不難; 半夜以後直接上頂樓, 睡醒後眼睛有完全的dark adaption, 由於下午已先看過星圖知道大概位置, 半夜以後找大概位置掃一下, 幾分鐘搞定

12. 沙鹿 apm 20x70ed可見NGC253; (前天)晴朗+透明度普通AQI66左右; 稍難但100%可以看到; 晚上10:30打完電腦後關燈(並非全暗), 等個10分鐘左右後開始找NGC253與看其他天體, 在疑似的大概區域3到5度區域間掃了20分鐘左右真的慢慢出現了................NGC253上面有5顆前景星(foreground star), 因為看得出傾斜與面積與些許面積(不小)所以不會覺得無聊: 由這個例子就可以看出dark adaption的重要性(所以這種找稍微難一些的星體我都比較會有耐心的前期後後掃來掃去, 通常會成功; 如果不成功改天再試, 如果看了許多次以後還找不到再看星圖確定完全正確的位置在試)

13. 沙鹿 手持takahashi 22x60可見海豚garmma雙星星;很難但絕對做得到; 前後試了大約30-40次, 成功2次; 天氣+器材(雙統合圓+調整近視度數)+身體狀況三者缺一不可; 好像沒有所謂的middle ground, 不是給你解出兩顆漂亮的雙星, 就是一點都分解不出來......不過部分原因也是出於自己, 例如當天天氣或身體狀況不好我也懶得把器材調到最好, 反正這種情況下器材調到最好應該也是無望

14. 由13導出一個用WO 22X70 ED可否看見可見海豚garmma雙星的問題.(1)手持幾乎不可能, 主要WO 22X70 ED受限於體積與重量這點, 就算看得到也太累了(2)WO估計上架可以接近上架的takahashi 22x60但小輸takahashi 22x60....高橋出瞳徑低些, 星點細些, 光軸準些, light scatter/light baffle好些, 雙星顏色美些,倍率可能高些 vs WO 22X70 ED口徑解析力好些, 集光力強些(3)不要認為WO 22X70 ED爛, 這只雙筒很嗆, 以後有機會再說......

15.沙鹿 apm 20x70ed可見omega星團; 天氣晴朗透明度高+半夜後: 超簡單; 利用omega星團接近中天時加以觀測, 超亮超大又能解出外圍不少星, 其實除了背景亮了不少影響美感外其實與山上的omega星團差距比想像之間少了許多, 覺得就算沒有比月球的視直徑大也差不了多少

16.沙鹿 使用WO 22X70 , Takahashi 22x60, Apm 20x70掃射手座都是一享受...........想要快速在各疏散星團/球狀星團/星雲之間遊覽就出動Apm, 想要求最大的美感與大一點的面積就出動Tak,極端狀況下是先出動Apm, 為了多解析M22/M24......再出動Tak, 不過通常Apm就夠用了(待續)


主題: 回覆: 沙鹿的星空
作者: yao2018-10-22 09:59:34
不負責直視中雙筒鏡簡述(主要手持用途)

1.WO 22X70 ED
任何上架觀測者首選, 性能最強, 星點細顏色好, 日用非常好, 與富士16x70相比絕對應優先挑這只,月面特徵殺手(上架至少60個左右??)

2. Tak 22x60 APO
高階雙筒鏡同好首選 ,需要對天體位置夠熟, 星點最細, 星點顏色最好, 日用最好, 視野最窄只有Nikon 18x70 sp一半, 土星環與本體手持可見分開,月面水鳥特徵殺手

3. APM 20X70 ED
進階雙筒鏡同好首選 ,所有想到的指標都夠好, 星點細顏色好,日用非常好,與Nikon 18x70 sp相比主要勝在日用的色差與倍率, 小小勝星點顏色

4. Vixen 20x80
深空星雲星系首選, 適用深空天體的厲害one trick pony, 實證可見M101與M83的兩條懸臂, 可以加上77mm or 82mm UHC濾鏡, 登山看深空首選

5. Nikon 18x70 SP
任何雙筒鏡同好首選 ,最推薦的雙筒, 最經典, 星點銳利, 星點顏色接近ED, 牛角眼罩對於觀測地旁邊的光源與月光汙染幾乎可以完全濾掉, 牛角眼罩抵住雙眼對手持也有些許幫助.........唯一的缺點是沒有用ED以上鏡片日用花草不好看

6. APM 16X70
無Nikon 1870與Fuji 1670預算的首選, 星點細星點顏色差些, 光害區有eye glint, 膠皮氣味重, 其餘沒有可以挑剔, 白天沒有Nikon 18x70 SP銳利與通透但是顏色好些, 比Fuji 1670 eye relief長, 鎂鋁合金也比較輕, 更適手持

7. Swarvoski 15x56 APO
有錢雙筒鏡同好首選 ,星點顏色同Tak 22x60 APO最好,比以上6隻都還適合手持, 廣角+邊緣修正好, 星空下vivid-living

8. Pro-Optic 11x70(尚未測試) 中高品質最輕的70mm雙筒??有ed ting等review證明
"The pain of poor quality lingers on long after the pleasure of low price wears off." These words echoed through my head as I placed my order for these 70 mm binoculars. I had planned to order the Orion Mini Giants ($269), but the low price of this pair caught me in a weak moment. As a result, I experienced "Buyer's Remorse" almost as soon as I hung up the phone. The binoculars arrived a few days later. They are well-constructed and apparently made in Japan. The lenses are multi-coated in a very dark green. There is no light cutoff from the BaK-4 prisms. The binos have a solid, serious feel to them, despite being even lighter (2.8 lbs) than the already lightweight Orion Mini Giants. Hmmm...Looking through the binos reveals a bright, sharp image, with very little softening or mushiness at the edges. The Pro-Optics have a smaller FOV than the Orions (4.0 deg vs. 4.5 deg) but they're sharper across what field is there. After a few tense initial minutes, I relaxed. Hey, these are good binos! They gave very pleasing views of the Pleiades, M42, and the Double Cluster. Sweeping through the Cygnus Milky Way is a lot of fun. These are going to come in handy for sweeping fields as I work my way through the Herschel 400. What's more, they are light enough to hand hold for several minutes at a time. The binos come with the standard battery of accessories I never use - two straps, a cheap hard case, and a piece of cheese cloth. There are two lens caps for the eyepieces and one huge cap for both objectives, which is "back- wards" and the only fault I can find with the binos. These Pro Optic binoculars are cheap, and they're good. Highly recommended!


主題: 回覆: 沙鹿的星空
作者: yao2018-12-03 10:58:51
雙筒鏡歷年紀實總匯(3)
17.沙鹿 可見M55 apm 20x70ed 不難 普通晴朗 , AQI100出頭 前幾天搞一個實驗, 看看像這種下班時候下午19:00光害比較大的環境下, 再加上 AQI100屬於橘爆的情況下, 能不能看到M55 ??答案無疑是肯定的, 不過魔鬼藏在細節裡, 這裡的橘爆是屬於臭氧為主的橘爆, 懸浮微粒只是稍微超標. 氣體基本上不會增加市郊光害的漫射, 也不會阻擋星光使之變暗😊等到21:00吧, AQI數值變化不大, 但已經變成懸浮微粒為主的橘爆,光肉眼看即知條件變差了, 也沒有在試M55, 因為M55的仰角極低, 而在光害區仰角低的光害會比非光害的地區慘很多, 估計是看不到了
18.沙鹿 可見M33之內的NGC604 WO 22X70 非常難-超難 半夜後+天晴+AQI低+中天 NGC604無疑是大挑戰, 不過應該是看到了, 只是沒有當下查星圖去對正確的位置(最後一哩路🤔).簡單說就是印象中是一塊淡淡光斑(只記得這樣😥). 至於還能不能在看清楚一點呢??我想還是有些機會, 但是機會是慢慢消逝, 畢竟沙鹿西屯區建案太多, 總體光害慢慢惡化中.........也許哪天頂樓漆個黑漆, 觀測時弄個黑布什麼的來增加一點機會
19.沙鹿 可見M110(??) takahashi 22x60 非常難-超難 半夜後+天晴+AQI低+中天 M31和M32無挑戰性, 不過M110就是另一個故事, 看到的可信度比較低(記憶中比 NGC604低)
20.沙鹿 可見M31之中的NGC206 takahashi 22x60 非常難-超難 條件同上 接近M32的NGC206大約見到2,3次, NGC206與M110相比比較容易, 應該是單位面積亮度較大
21.沙鹿 可見NGC2158/2157 takahashi 22x60 難(比想像中簡單) 條件同18 這個難的解釋是: 以2.2度窄角的視野內連同M35來說共有3個疏散星團可見, 方位也與星圖的位置相同, 當然NGC2157要難些, 不過能看到NGC2158/2157真的打破眼鏡,一般認為市郊不可能, 這裡我暫時把它歸因到takahashi 22x60上(對比+星點細+baffle)
22.沙鹿 M69/M70 apm 20x70 難 上半夜條件良好可見





主題: 回覆: 沙鹿的星空
作者: yao2018-12-03 11:00:35
夕陽前後用nikon 8x30 eii看的東西

1. 夕陽落入海平面上方的雲層;昨日夕陽落入海平面上方的雲層時大約有10層橘色至紅色的色條, 讚. 今日卻是橘色至紅色由上至下漸漸的過渡, 沒有色條.....昨日與今日海平面上方夕陽還好不算刺眼(警告, 要抓住夕陽落入海平面的時刻, 太早是不能直視的)
2. 估計夕陽落入海平面上方的雲層如果空氣品質特別好, 還是會刺眼, 甚至稍有危險(尤其加上大些口徑的雙筒)
3. 夕陽西下後的晚霞; 通常是西邊有捲曾云或是西邊無雲+空氣品質良好這兩種情況最好; 前者透過雙筒鏡有如染色的絲綢, 後者色彩變幻滿西天
4. 夕陽西下後的晚霞與雙筒鏡有關, swarvoski 15x56打敗nikon 8x30 eii有經驗的同好一眼可見......nikon 8x30 eii也比不過goto 8x42 ed
5. 夕陽西下後的樹草果實, nikon 8x30 eii此時色差看不出來. 亮度還夠
6. 夕陽西下後戰鬥機在天空西方的噴射凝結尾; 這兩天清泉崗戰鬥機下午5;30都會出現, 此時nikon 8x30 eii 8點8度的事也剛好把戰鬥機與噴射凝結尾全部fram 住,讚....... 上下噴射凝結尾不規則也可見, 唯一的缺點是戰鬥機位於視野邊緣並不清楚, nikon 8x30 eii不是以邊緣修正見長所以這是可預期的


主題: 回覆: 沙鹿的星空
作者: yao2018-12-03 11:03:06
雙筒比業餘同好想像的更為強大

1. 根據aokswiss網頁
(http://www.aokswiss.ch/ayo/main_bino.html#zubehoer):
With a binoviewer at a single scope, the brightness is halves, otherwise, the brightness is not double with a binoscope. But the visibility of faint structures especially at Deep Sky objects will be more than double as with only one scope. That mean in praxis, you will see with a 4" binoscope near as much as with a 8" singe scope (refractor) or a 12" dobsonian.

2.根據cff telescope對cff telescope 135mm F/6.7 Binotelescope的評述
Bino minimum length – 850 mm;
Bino maximum length – 1000 mm;
Back-focus distance with EMS – ~55 mm;
Back-focus distance without EMS – ~250 mm;
Focuser – 3.2″ Starlight Feather Touch (FTF3235);
Weight – 21 kg, as delivered.
Price:
13 990 Euro, includes VAT 23%. Net export price – 11374 Euro (non EU countries);
Includes:
EMS-UXL system
CNC made ring type holder with central handle
Dovetail, Losmandy Type, 300 mm length, lightweight
Handle
Dew shield end cap
Dust end cap for EMS
Finder bracket shoe on one of the focusers
it depends what you compare it with and how you approach the idea :-). $13k is a sensible amount of money, however, considering that this has the light gathering capability of a 190mm refractor and your brain is working 'naturally' thus compensating a lot, one might put in the balance if the $13k is better vs $20 - 26k for a 200mm refractor, with all the pros and cons it comes (size, weight, mount requirements).

3.根據松本龍郎的facebook:
Through my long time experience and according to the numerous opinions of the EMS-BINO users,
I can definitely say that, 10cm-BINO >> 14cm single scope; 13cm-BINO >> 18cm single scope: 15cm-BINO >> 20cm single scope,.., and so on.
Do you still say that carrying 20cm single refractive telescope is far more easy and advantageous than you carry a 15cm Binoscope?


主題: 回覆: 沙鹿的星空
作者: yao2018-12-03 11:03:55
清晨5:00快要天亮, 而且還有月齡19的月亮, 只是在台中市郊(沙鹿), 用小小的22倍雙筒甚麼都看不到??大錯特錯, M41/46/47/50都有數十顆星........原因????

1. (5:00前後)快要天亮航海曙光還是夠暗:只要不是看暗弱天體如星系
2. 空氣品質AQI=47,還算夠好:空氣品質爛會加強散射月光汙染與城市光汙染, 空氣品質對市郊觀星有次於雲層厚薄的影響.市郊觀星絕對要把握空氣品質綠色訊號時刻
3. 半夜後市郊光害較少:無論如何與前半夜有差
4. 人眼dark adaption:睡覺起來觀星, 完全100%的dark adaption
5. 倍率&雙筒; 有個Vixen 70mm ed雙筒同好說他喜歡30至40倍的情況下看星雲星團.........我是覺得對於市郊的常見疏散星團來說雙筒倍率22倍其實足夠.
6.對主要天體位置一定要比較熟: 5:00前後不允許還要浪費時間查星圖,而查星圖的同時也是破壞之後20分鐘以上人眼的dark adaption,禍不單行
7. 正向直視手持高倍雙筒的優勢: 指哪打哪, 隨心所欲. 最舒服是雙眼, 最靈活的是雙手
9.器材的品質: Takahashi 22x60星點細與對比強, 適用於市郊尤其疏散星團


主題: 回覆: 沙鹿的星空
作者: yao2018-12-03 11:06:12
(之前......)看到了綠閃, 還看到了綠閃後一兩秒的solar flare

為了怕傷眼, 從日盤面落入海中之後才開始把朗峰平場8x42 ED對著日盤面, 大約日盤面落入海平面的1/7時, 在大約2點方向與10點方向有幾乎兩道同時出現的綠閃, 持續大概兩秒, 我只能說是生平最好看的綠(螢光亮綠)
之後緊接著得更誇張, 一道好像1點方向畫出的solar flare噴出, 雖然說我從沒有看過solar flare但我從它的形狀, 大小, 時間判斷它是solar flare無誤.........想不到有任何這麼巧的可能, solar flare持續大概兩三秒吧
另外, 昨天的日盤面分層與分層顏色也很漂亮
另外, 昨天的日盤面落海時剛好有小輪船做它的前景
另外, 整個日盤面落海完全沒入海也看到了
唯一的缺憾是沒有拿更好的Tak 22x60來看, 看來我以後需要幫它做一個3cm aperture mask
我看的綠閃與solar flare沒有拍下來, 與wiki上的綠閃完全不同(wiki上的綠閃如圖)
只能說, To see is to believe
看天氣這幾天好像還有機會??


主題: 回覆: 沙鹿的星空
作者: yao2018-12-03 11:13:02
(之前......)看到了綠閃, 還看到了green rim

是的, 前天與昨天<自家屋頂>連續兩天綠閃

使用cannon 10x42 is, 防震未開啟, 黃色落日面還是太亮了一些, 還是應該用aperture mask縮口徑至30mm, 畢竟與nikon 8x30 II相比多了一倍集光力.............如果是看上半部黃色下半部紅色,色層很多的落日盤面, 42mm才不會太刺眼

日面呈現color shade變異不太大的黃色, 差別主要在上日面比下日面亮, 而且上下還是沒有那麼戲劇性的亮度變化, 所以一條一條的色層幾乎沒有..............還以為是眼睛或望遠鏡壞了(日盤面不美, 就是這麼差)

主角綠閃就像一般經典??的綠閃, 主要特徵是在日盤面的正上方, 出現了5-6秒, 然後搞個10幾秒又消逝了(關於時間沒有注意, 所以有可能誤差很大, 看看就好).........然後又如此這般重複了數次, 搞到好像不用錢似的, 我算了有五次(至少四次).............而且我還沒算大部分日盤面落入海之後還是有兩,三次都是這樣, 畢竟可以想見, 大部分日盤面落入海之後上方的綠閃受雲層/大氣厚度/空氣汙染/的影響, 沒那麼綠, 灰灰的不好看, 根本不綠能算綠閃好嗎??

副主角green rim出現在上半邊日盤面, 出現在不知道第幾次的綠閃之後, 反正出現在第一二次後吧, 日盤面旁邊大概半圈, 半圈之中當然有些地方不太確定有沒有............green rim接近日盤面,細節容易被喧賓奪主,不容易哦

綠閃也有出現在green rim上, 不過還不能真的確定那是綠閃

綠閃動態的描述大概就像太陽長天使環, 然後又消逝

附上wiki的green rim, 有像


主題: 回覆: 沙鹿的星空
作者: yao2018-12-03 11:27:36
(松本以外)雙筒鏡最大迷思-Illumination
https://www.cloudynights.com/…/comparing-binoculars-go22x85…

請注意中段講述Vignette, Illumination, Image Brightness的三大部分

1. 你以為20x80, 15x70的有效總集光力會勝過Tak 22x60 apo嗎??那你就錯了

2. Illumination相當好的WO 22X70 ED(絕對不比Fujinon 1670差)的有效的有效總集光力與Tak 22x60只相差15%

3. 屋脊的有效總集光力通常比保羅差(似乎在原文Vignette, Illumination, Image Brightness以外的地方)

4. 高品質雙筒有效集光力絕對比下一般的雙筒:本篇文章倒數第二段:The Fujinon 16x70(WO 2270 ED也是) has a larger illuminated area than any 20x80 binocular

5.小Exix Pupil也能立大功:本篇文章末段No other binocular I have ever seen does so much with so small an exit pupil. I have no doubt in my mind the illumination, and therefore brightness, of the Tak22x60 results in it performing well above its exit pupil size class. In fact it may even perform as if it were 1/3 to 1/2 again larger.

6, 舉例, 富士95%透光力只是中心區域而已.( 到了物鏡的邊緣llumination已不知掉到多少)

7. EDZ的中心Illumination的指數中還沒考慮各廠牌中心透光力的差異, 考慮各廠牌中心透光力後差異會更大

8. EDZ指數中, 雙筒望遠鏡綜效=口徑的開根號x倍率x望遠鏡的品質(0.8-1.2),其中中望遠鏡的品質有一部分就是llumination

9. 合理推斷松本雙筒在EDZ指數中的望遠鏡的品質中的數值還要超過1.2(主要是illumination應該可以接近100%??)


主題: 回覆: 沙鹿的星空
作者: yao2018-12-03 11:57:11
Tiny Dipper asterism
外國同好發現的

https://www.cloudynights.com/…/624795-asterism-in-vulpecula/
15x70 binoculars可見

it is easily visible on chart 65 of Uranometria.

Its center is about 2° west of NGC7052, and all the stars are brighter than magnitude 9.7.

It looks like a dipper with a rounded bottom to the cup.

Even more exciting, 5 of the stars are doubles according to Megastar, though one would require a 12.5" aperture, high power and perfect seeing.


主題: 回覆: 沙鹿的星空
作者: yao2018-12-03 12:33:33
 Visual Astronomy at the Telescope's Eyepiece

Mel Bartels

As a small child I remember being driven back to Portland, Oregon at night after a visit to relatives in the countryside. I lay in the back of the station wagon, peering up at the sky through the rear window. The stars were so brilliant against the darkest black of skies. It hurt my eyes to look at the brightest stars. What a contrast to the washed out city skies of Portland, even in 1960.
The Greek astronomer Hipparchus in the 2nd century BC invented the magnitude system, where the brightest stars are of 1st magnitude and the dimmest are of 6th magnitude. I suspect that this system was in use beforehand: it’s common for humans to divide groups of things into sixes and it would have been natural for us to call the brightest stars “first class”.

The magnitude system is logarithmic, not linear. This no doubt because our eyes work logarithmically (or at least semi-logarithmically). For example, a star that is 1 magnitude brighter is 250% brighter; conversely a star that is 0.1 magnitudes dimmer is 10% dimmer.

The first lesson then is that we cannot get hung up on linear percentages, instead we must think in logarithmic magnitudes. This is difficult because discussions today are almost universally in percentages, which is completely misleading. Illumination drop-off at the edge of the eyepiece? Stated in percentages (e.g. 15% sounds terrible), should be in magnitudes (e.g. 0.06 mag, unnoticeable visually). Mirror coating reflections? Stated in percentages (e.g. 92%) should be in magnitudes (e.g. 0.04 mag loss). It is very difficult to see differences of 0.2 magnitude or less. And when the view is dimmed, both object and background are equally dimmed, leaving the contrast unchanged. Unless the view is grossly dimmed, the unchanging contrast means that the object does not lose visibility. I will be using magnitudes exclusively just as charts and observing manuals.

I've been enthusiastically observing for a number of decades. Here are the factors that influence what I can see that night through the eyepiece of my telescope.

• Focal length gives you scale; it's important to understand the role of magnification. Check out my article on magnification.(https://www.bbastrodesigns.com/Telescope%20Magnification.ht…)
• Aperture increases visibility and detail not only because of greater light gathering power but also because the greater magnification brings the object in closer.
• Seeing the object in a larger scope then returning immediately to your smaller scope can result in a half magnitude gain.
• Observer experience is worth 2 magnitudes (I have a series of sketches of M31 from childhood onward).
• Observer variation is a half magnitude or more.
• Age matters a magnitude: young kids can see very faint stars; as we get older, our lens yellows and ability to detect fades.
• Knowing where to look and what to look for worth a magnitude.
• Averted vision is worth a magnitude.
• Dark adaption continues to produce increasing benefits for hours, ultimately worth maybe a half a magnitude.
• Field baffling is an overwhelming factor: the difference between nonexistent and fully baffled views can be worth magnitudes.
• Covering your head with a black cloth also yields improvements, perhaps on the order of a fraction of a magnitude.
• Time at the eyepiece is worth a magnitude (objects gradually become recognizable or detectable over a period of time, and then they fade after a prolonged period of continuous observing).
• Comfort at the eyepiece is worth a half magnitude.
• Rested eyes are worth half a magnitude. I often take short breaks throughout the night. Upon returning to the eyepiece I can see more until my eyes tire.
• Sky transparency is such an overwhelming factor; on rare perfect nights I’ve seen scopes perform as if they had almost unlimited aperture; let’s call superb sky transparency worth a magnitude or two.
• Filters are worth a magnitude.
• Visibility appears to correlate most with aperture, then apparent size (the greater the aperture, the greater the apparent size, limited by the full field of view).
• True binocular or two eyed viewing results in a half magnitude gain in stellar limiting magnitude and about a magnitude gain for extended objects. Check out Bruce Sayre's experiences building and observing with binoscopes over the many years.(http://www.brucesayre.net/) And check out the last four years of the Oregon Star Party Telescope Walkabout featuring binoscopes 2017, 2016, 2015, 2014.(https://www.bbastrodesigns.com/osp17/OSP17.html)

Make these factors work for you and you can gain magnitudes in observing prowess. It’s like having a much larger scope on hand.

Why do amateurs ignore these factors in favor of obsessing over minutia like their telescope’s diagonal coating quality? Sometimes we humans become superstitious and engage in myopic inquisitions when the situation is difficult or fuzzy. Have courage, don’t obsess over some detail of your telescope and instead focus on the factors that matter.

Notice that the lines are banded or thickened. You might fall slightly above or below these bands based on the factors discussed earlier. Beware of anyone or any calculator that states overly precise limiting magnitudes. These are at best guides and give a false impression that an object is either perfectly visible or perfectly invisible. Objects on the edge of visibility come in and out of view over a period of time. One night that object might be visible three times in a half hour (my standard for detectability). On another night it simply is completely invisible. On rare perfect nights not only can I detect it much of the time but there is detail too. Also if the galaxy or cluster or planetary is unusually large, then the detection limit will suffer. Note that as aperture increases, minor differences (say between a 20 inch and a 22 inch telescope) become insignificant, even undetectable except for rare edge cases.

At first aperture is everything, then it is nothing; eventually it simply is. At first we can't get enough aperture. Then almost like a boomerang we trim way back in aperture. Notice how many experienced amateurs own not only their big scope but also a smaller scope? Finally, aperture takes its place in the pantheon of factors, being traded for field of view and for convenience of viewing. A 6 inch [15cm] is a perfect aperture to learn how to observe. With it you can see thousands of objects from a dark sky. A 12 inch [30cm] will resolve almost all clusters and show galaxy groupings. If you think that you “need” large aperture to see the skies, that small aperture won’t work, then something has seriously gone amiss. Large aperture makes it more difficult to learn the art of observing. Do yourself a favor and spend a lot of time observing with smaller scopes too.

What magnifications should be used? I favor three strategies both based on exit pupil (the eyepiece's focal length in mm divided by the telescope's overall focal ratio [e.g., 24mm eyepiece on a F/6 scope produces a 4mm exit pupil]):
The first is based on Richard Berry's advice. Arrange your eyepieces so that they give exit pupils as following:
5-7mm Richest Field observing
3-5mm best deep sky observing
1-2mm best detailed observing (globulars, planetaries, lunar and planetary)
The second is based on Stephen O'Meara's comments (e.g., his Herschel 400 Observing Guide). He uses modest aperture (4 inches [10cm]) at low, medium and high powers. He takes his time studying the object carefully at each power. His low, medium and high exit pupils are:
4.4mm
1.4mm
0.96mm

If you are wondering who to look to for observing advice, pay attention to the top observers who use smaller scopes, like O'Meara.

The third is a strategy that I've developed in response to the super wide angle eyepieces available today. It allows me to see large scale objects otherwise too big for a given scope. I call this strategy “framing” or “composing” the view where the object is magnified to fill the eyepiece’s field of view as much as possible with a nice border around it for contrast. Increasing the apparent object size beyond this 'cut-off' results in a less pleasing more difficult view. Here, the widest possible field of view is important, even at the cost of more glass for the light to pass through. In this approach, I smoothly decrement the exit pupil. I use a set of exit pupils as follows (note that the typical set of eyepieces does not fit nicely):
5-6mm for largest scale objects
3-4mm for medium scale objects
1-2mm for small scale objects

Finally, poor seeing conditions especially with larger apertures will limit magnifications to 200-300x or 2-3mm exit pupil.
It helps to have an observing program and plan your evening's viewing. The Astronomical League has a number of observing plans(https://www.astroleague.org/observing.html). Or create your own, i.e., comparing the shapes of globular clusters in the Sagittarius region or colorful double stars in Bootes. Use a table for your eyepieces, tools, charts and texts or for your tablet and lightshield. Plan on 20 minutes per object. I strongly encourage you to sketch what you see. This hones your observing skills and brings out details in the object. Observe at all three ranges of power: low, medium and high.

For observing large scale regions of the Milky Way and more on organizing observing and sketching sessions, see my dark nebulae observing comments at
https://www.bbastrodesigns.com/…/Observing%20Dark%20Nebulae…
https://www.bbastrodesigns.com/pleiades.html

Averted vision works best if you know where to aim your eyes in the field of view. Here's a chart to help.
For extended objects, things are not as simple as stars. For starters, it is not possible to increase the surface brightness of an extended object by increasing the aperture. An example: take an object of 10 magnitude/ square arcsecond as seen by the unaided eye at night, exit pupil open to 7mm. Now, look at the object through a 10" scope. If there is no magnification to the image, the surface brightness will increase by the ratio of the scope's aperture to the eye's aperture squared, or, (10"/0.3")^2 =~ 1000x. However, in order to fit all of the light from the 10" aperture into the eye's exit pupil, we must use at least 33x. 33x will dilute the image brightness by 33^2 =~ 1000x, so we are back where we started. In fact, because of mirror coatings not reflecting 100%, and the small obstruction caused by a diagonal, the image brightness per area will actually be a little less than with the unaided-eye.

This leads to the interesting conclusion that the brightness of the sky glow as seen in the eyepiece is entirely dependent on exit pupil. At a given location on a given night, no matter the size of scopes, if they are giving the same exit pupil, then the sky glow brightness will be very similar.
So why then is aperture the dominant factor? If exit pupil or sky background brightness is kept constant, then as aperture increases so must the magnification. The object appears larger and is easier to see. It’s like moving in closer. If magnification is kept constant then the object and background brightness increase, also making the object easier to see.

Conduct your own experiments; I have. Find a large rock and walk away from it until you can't see it. Now walk towards it. Do this in dark skies and in a forest under dark skies. Try this with a small rock. Take a magazine page then shine a very dim flashlight on it. Walk away. Now walk towards it. At first it simply becomes easier to detect; eventually the largest shapes are discernable and finally large print. Walking towards the rock or magazine page is equivalent to increasing aperture.
Better yet, take a nice enlarged print of a galaxy or globular cluster or planetary nebula or dark nebula. Dimly light it. Walk away and towards it. Not only does the object become easier to see as you approach the print, individual stars and detail become more visible too. That's aperture and magnification at work.

Very wide fields of view at widest exit pupils allow for more aperture for a given field and also increased detail because the objects are spread out more. For more on this, check out my "Why Am I Seeing More" page.(https://www.bbastrodesigns.com/The%20New%20Sub-F3%20Richest…)
What is sky glow brightness? The night sky, even at very dark sites, glows faintly due to zodiacal light and airglow. See Brian Skiff's discussion at http://www.astropix.com/HTML/L_STORY/SKYBRITE.HTM. You can measure the darkness (or brightness) of your night using a sky glow meter available at http://unihedron.com/projects/darksky/. Dark sky sites have readings close to 21.5 magnitudes per square arcsecond. Observing through a telescope with your eye's pupil fully opened results in a sky glow in the field of view equal to that of the night sky. Magnifying the image results in smaller exit pupils, the useful maximum magnification or smallest exit pupil being close to 1mm. The sky glow brightness drops more than 4 magnitudes to close to 26 magnitude as exit pupil shrinks to 1mm.

There's a great deal of discussion about Blackwell's studies and Clark's presentation. Here's my take:
So how can we see the object in the scope? The eye is a marvelous detector of low contrast faint objects, but the light must fall on large numbers of rod cells so that the eye-brain can detect the slight contrast difference between object and background. The slighter the contrast, the more rod cells that the object's light must fall on in order to generate a signal difference between object and background. By increasing the telescope magnification, the object is magnified so that its light falls on many rod cells. There are two points to consider when an object is in the field of view of an eyepiece. The first is the object combined with the sky glow from the atmosphere that is directly between us and the object, and the second is a point away from the object, which is the sky glow only. The ratio of brightness between these two points is sometimes called the object contrast. This contrast value stays constant despite any increase in magnification because both points are equally dimmed.

The seminal reference on visual astronomy is Clark's book, "Visual Astronomy of the Deep Sky". In it Clark explains and quantifies the visual detection of objects. Clark has added additional comments since the book's publication, at http://clarkvision.com/visastro/omva1/index.html Clark uses data from a World War II study by Blackwell.

Here a brief presentation of the Blackwell data. The eye's detection ability with sky background brightness values from 21 to 26 is:

From the chart we can see that large exit pupils result in the best ability to detect objects over a wide range of apparent sizes. As the exit pupil shrinks, the ability to detect objects declines and becomes concentrated on apparent sizes of about a degree. We can see this by plotting best apparent detection size against declining sky background brightness. Here are two visualizations of the data:
The data and its interpretation has been the subject of intensive discussions between Prof Clark, Nils Olaf Carlin, Harold Lang and myself.

For Nils Olof Carlin's analysis of Blackwell's original data, see blackwel.html.(https://www.bbastrodesigns.com/blackwel.html) Here, Nils shows that the best contrast comes when the background is dimmed below visual detection and the object is about one degree in apparent size.
Bill Ferris has generated a series of ODM matrices that compare the variables with each other: http://members.aol.com/billferris/odm.htm

I wrote a visual detection calculator(https://www.bbastrodesigns.com/VisualDetectionCalculator.htm) that presents the data by aperture and exit pupil. I believe that the whole issue of visual detection needs more observations and possibly a new model. The detector that I wrote uses the Blackwell data. Like any ground breaking study, there remains much to be done. The study was done with two eyes - how does a single eye do? Objects in with complex isophotes need to be studied, distractions of other objects in the field of view needs to be investigated and variations in the color of the objects need to be checked. Also needing observations is variation in the ages of the observers and especially telescope construction features like baffling and cleanliness of optics.

Geg Crinklaw has invested a great deal of time into improving his visual detection calculator based on empirical results at the eyepiece. See his SkyTools software(https://skyhound.com/skytools.html )and in particular his comet chasing page.(http://cometchasing.skyhound.com/)
EOD


主題: 回覆: 沙鹿的星空
作者: yao2018-12-03 12:36:17
裕眾2.3 x 40星座鏡觀後感與評論

今天半夜三點星空狀況普通, 終於把手上的裕眾2.3 x 40星座鏡稍微仔細地用看看. 簡言之, 用過之後很滿意, 以後不想賣掉了.
御夫座所有的主星都可以塞入視野中, 本來空無一物的五角形中間也多了幾顆星/獵戶座lamda星與旁邊一顆星看起來可愛/獵戶座主體加盾牌的大部分可見/獵戶座盾牌從殘缺變完整/ 卯宿與畢宿同一視場/ 天兔座便完整了/ 麒麟座本來似無一物也變精彩了...........總之, 親愛的, 星座鏡把星座變有趣了

至於一些簡單的梅西爾, 市郊利用星座鏡就能看的到M6/M7/M8.....

星座鏡算是最輕鬆(通常躺者手持). 最小巧輕便的觀測工具.

愛爬山的同好應該考慮它. 與高倍中口徑雙筒似乎也配的不錯. 而由於它容易使用的特性, 似乎特別適用於男女朋友, 試想男女朋友各持一只星座鏡同步觀測同一星區是多棒的事(應該是男生在解說吧)

星座鏡重點:对于伽利略式望远镜来说,没有固定的出瞳距离(眼点高度)和视场角。眼睛越向目镜方向靠,视场角就越大。眼点为 8mm 时,视场角大约11度;眼点为5mm 时,视场角大约是15度;如果你把眼睛凑到目镜表面大约 2~3mm 的话,能得到的最大视场角大约是28度了。

星座鏡重點(承上):戴眼鏡之後視野小很多, 視野越小樂趣也越小

星座鏡被大家忽略的地方(自己猜的, 不知道對不對)之一: 由於沒有菱鏡, 鏡片數量也比一般雙筒少了許多, 如果發霉不嚴重的話, 曬個太陽就好了(請看圖1)

星座鏡被大家忽略的地方之二: 星座鏡的出瞳就是使用者當時的出瞳, 所以星座鏡當然能提高星等1至1.5等, 但是背景的亮度始終與使用者肉眼(1x)所見的亮度一樣. 也就是說星座鏡在提高星等上能變出魔法, 但是對於把背景便暗這件事上是無能為力的.

星座鏡被大家忽略的地方之三: 應該可以加上兩只兩吋UHC/OIII/H beta濾鏡觀測. 例如很久以前scott walter hudson就利用Lumincon UHC肉眼(1X)觀測到巴納德環;還有北美洲星雲, 玫瑰星雲......都可一試

星座鏡被大家忽略的地方之四:星座鏡前沒遮光, 後沒擋光. 所以可以DIY一下, 這樣效果(尤其在城市內)會好些

星座鏡被大家忽略的地方之五;挑戰極限.例如阿拉斯加, 德州星空暗, 這兩個地方CN上都有人能看見極限星等7.5等, 所以肉眼看不見的M81, 似乎變成了可挑戰的目標.退而求其次, 星座鏡帶到台灣的高山上挑戰NGC253也不是夢想......另外還有一大堆黑暗星雲...........至於NGC7789之類應該不算挑戰(??)

星座鏡被大家忽略的地方之六; 星座鏡是除了肉眼(1x)之外最輕鬆的觀測工具


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 13:42:47
Saturn in Takahashi 22x60 binoculars

一大堆不懂的人都說30倍以上才可以看的到土星環與本體分離, 其實22倍好質量的雙筒就可以了(https://www.cloudynights.com/…/466473-saturn-in-takahashi-…/)

資料原文如下:Took the Takahashi 22x60 binoculars out a few minutes ago and got a good view of Saturn and one moon. I could clearly see the dark spaces between the rings & planet at the 10pm & 4pm positions.

手穩的如果有靠牆還是甚麼支撐之類的, TAK2260土星環與本體分離用手持方式間歇性可以看到


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 13:46:44
星座鏡周邊產品

M48 Filter Adapters
WideBino-Goggle
http://www.kasai-trading.jp/widebino28e.html

goggle mount
goggle
M48 mount
M48



主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 13:51:47
冠昇光學GSO出了傳統卡鏡:6" f/12和8" f/12
https://www.cloudynights.com/…/624303-new-at-6-and-8-class…/
https://www.teleskop-express.de/…/p10753_TS-Optics-8--f-12-…

其實我個人是認為這個焦比是應該6" f/12和8" f/15, 畢竟f15才夠classical, 然後產品線延伸至10" f/17和12" f/20, 也就是說6"至12"經濟型的傳統卡鏡將來必是GSO的天下, 畢竟我的夢機cff telescope 30cm f20對一般人包括我自己來說還是貴, 相信GSO能夠把30cm的售價大大拉下的話, 還會進一步吃下一些Celestron Edge 11"的市場

cff telescope 30cm f20 vs 12" sct(只論重要的, 明顯的, 我知道的)
1. 散熱快(合理推測2x以上)
開放式鏡筒+n個背面散熱裝置+主鏡mass較小.....所以
cff telescope 35cm以上才建議主鏡用特殊材質
2. 對比好
30cm f20中央遮蔽率23%+精度好些
3. 鏡筒重量差不多
30cm f20 17.8 kg
4. 沒有mirrow flop
5. 沒有sct corrector plate+拍行星不用巴羅延焦, 所以沒有鏡片紫光吸收
6. 目視使用的目鏡會更便宜, 更舒適些
7. 露水問題好些

10"還好, 不過還滿怕GSO在12"上搞封閉式鏡筒, 一旦沒有
cff telescope 30cm f20 n個背面散熱裝置, 使用一搬材質的鏡片肯定不行, 如此一來搞個ULE glass售價拉不下來, 那還不如買cff telescope 30cm f20呢

圖一 CFF TELESCOPE 30cm f20太陽觀測版本
圖二 CFF TELESCOPE 35cm on Losmandy G11
圖三 GSO傳統卡鏡6" f/12


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 13:55:40
經濟的目視彗星濾鏡Astronomik UHC-E(相對於Lumincon comet filter)

根據https://www.cloudynights.com/topic/639435-ts-optics-uhc-filter/

以下為中頻寬UHC(30um-50um)
DGM VHT
Starguy UHC
Explore Scientific UHC
Optolong (Yulong) UHC
Astronomik UHC-E
the Telescope Service UHC

以上至少Astronomik UHC-E是有效的, 因為它沒有濾掉Swan bands

Swan bands
Features of the spectrum of the carbon molecule C2 (diatomic carbon), first investigated by the Scottish scientist William Swan (1818–94). These bands are prominent in carbon stars and cometary spectra. Numerous lines are present throughout the optical and red region of the spectrum, with strong features at 438, 474, and 516.5 nm.
(跟據http://www.oxfordreference.com/view/10.1093/oi/authority.20110803100545226)

圖一 swan bands
圖二 astronomics uhc-e


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 13:58:03
找仙女座NGC 7686的時候, 西邊正4度的地方有一個asterism, 像極了北斗七星, 似乎還沒人提過??

位置: 仙女座西北, 其中斗杓頭兩顆位於蠍虎座
器材推薦: 8X-12x雙筒好看
時間: 約9: 00過中天
難度: 對蠍虎座熟的話幾乎沒難度, 不熟蠍虎座的也不難
相似度: 90%
好看度: 8x-雙筒70%,10x-雙筒80%, 12x雙筒95%


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:00:09
An asterism west of NGC 7686 remarkably resembles BIG DIPPER of the BIG BEAR constellation. An 8x binocular is enough to show its beauty and resemblence, and I believe if you have nikon se 12x50 at your disposal, when you sweep at this astreism, you will feel you are heads over heals fall in love with this one.


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:07:59
Takahashi 22x60 apo手持(躺睡袋+墊枕頭)成功解析k Puppis

I easily found success in resorving k Puppis by a hand-holding Takahashi 22x60 apo, Success rate is above 90% to say the least.

尋找難易度: 15%左右非常容易
成功解析度: 90%以上成功非常容易
美麗度: 90%以上
意義度: 100%, 直接宣告高質量22倍雙筒手持輕易突破分解雙星10秒大關

Both k1 Puppis and k2 Puppis are bright blue B-type stars of nearly equal brightness, +4.50 and +4.62, respectively. To the naked eye, the pair has a combined magnitude of +3.80. On the sky, the two stars are separated by approximately 9.9 seconds of arc along PA 318°. The optical pair can be distinguished easily with a small telescope.

亮度高+白藍光(B-type stars)+亮度差異小=美麗解析k Puppis
Cannon 10x42 is開啟穩像應該也可以成功<手持>??


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:13:52
Takahashi 22x60 apo手持巡天找到有趣的星聚, 我叫它鍋鏟星聚(Turning Shovel asterism)或鏟子星聚(Shovel asterism)

位置: 大犬座左下方, η (eta)下方
正確位置: Collinder 140主要的亮星與最緊臨Cr 140的東北方三顆亮星
尋找難度: 10%
辨認度: 75-85%
精采度: 85-90%
器材: 最好做成是兩度到一點五度視野. 因為Takahashi 22x60 apo還會將船尾座的兩顆亮星搞到視野邊緣(2.2度)


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:15:52
Collinder 140


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:18:43
Takahashi 22x60 apo手持巡天找到有趣的星聚, 我叫它聖誕樹星聚(Chrismas Tree asterism)

位置: 仙后座delta星東北方
尋找難度: 10%
辨認度: 70-85%(樹根仙后座χ色澤偏黃)
精采度: 85-90%
器材: Takahashi 22x60 apo會將聖誕樹星聚剛好全部塞入視野(2.2度), 2.5度視野構圖應該會好些


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:29:06
月面觀測我也只是隨便亂看, 很蔡......

不過在月面入門觀測方面, Nikon SP 18x70與WO 22X70或Takahashi 22x60的確<不是同一個層級的雙筒>

1. 倍率: Nikon SP 18x70實際上大約為17.5-17.1倍(根據cn裡的edz大師), 所以Nikon的倍率還不到Takahashi的80%, 月面特徵的面積大概就等於Takahashi的65%到60%, 所以一眼就會發現Nikon SP 18x70可以辨認的月面特徵少了很多.
2. 亮度: Nikon的18倍亮度無法忍受, 亮到全面發白令人眼瞎. Takahashi的22倍亮度還可以忍受,惟看了幾分鐘後必定要休息才能繼續, 而且亮的程度還是呈現月亮的本身顏色.Tak 22x60單位面積亮度比Nikon 18x70約80%x80%X85%(Tak 22x60有效集光為高階70mm雙筒如WO 22X70的85%)=53%
3. 色差: Nikon SP 18x70接近望時月球邊緣色差一眼可見, 惱人.Takahashi 22x60接近望時月球邊緣色差不可見.
4. 視野內的月面魄力; 由於Takahashi 22x60倍率高加上窄視野, 所以視野內的月面佔總視野的很大面積. 乍看之下中間1/3是月面, 左右上下各1/3是暗視野, 很自然,月面魄力夠.Nikon SP 18x70倍率低加上寬視野, 總覺得視野內空空洞洞的, 月面魄力不足.

補充
從來沒仔細看, 而且我99%都是手持. 應該實際上Takahashi 22x60所有月海都看的到, 史密斯湖/中央灣/氣海/曙灣這類月海都看的到, 再加上許多的月坑, 我猜仔細看可以看到80個月面特徵. 相反的, Nikon SP 18x70我猜仔細看可以看到50個月面特徵,但是亮到全面發白令人眼瞎.所以月面入門觀測方面Nikon SP 18x70與WO 22X70或Takahashi 22x60的確<不是同一個層級的雙筒>

結論
WO 22X70或Takahashi 22x60在月面入門觀測方面可以令人滿意(缺點是太亮了一些, 需要觀測一段時間休息再繼續或減光)
Nikon SP 18x70不適合用在月面入門觀測方面(過份亮+色差+倍率不夠+視野內的月面魄力不足)


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:30:39
天鵝座61, takahashi 22x60可輕鬆手持分解之雙星

尋找難度: 20%
分解難度: 20%-30%(正常條件下的難度)
美麗程度: 85%(絕對超過75%)

天鵝座61.兩顆亮度相近而且能輕鬆手持分解之雙星. 重點是兩者呈現橘紅(或紅橘)的顏色, 如一雙黑中窺伺之橘紅眼, 美麗😊


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:41:10
2018 12 3晚10:30沙鹿天氣不錯.以Lunt 16x70與Takahashi 22x60觀測46P/Wirtanen成功.

透過這兩只雙筒面積都不小, 但是無法分辨慧核.真的<感覺>有接近5等. 差別在Lunt 16x70裡彗星比較小而亮, 比較沒那麼圓.

Takahashi 22x60裡彗星比較大而暗些, 非常圓,很像下面這圖片https://www.vofoundation.org/blog/in-the-sky-this-week-november-6-2018/


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:47:37
2018 12 16晚8:30沙鹿天氣不錯.以Nikon sp 18x70觀測尚未中天46P/Wirtanen, 不知是否受月光影響, 比12月3日又暗又小.

順便試了一對宇隆UHC 77mm濾鏡加在Nikon sp 18x70前, 裝卸3次左右前後比較, 由於月光還在雲內雲外不時露臉, 加上46P/Wirtanen還有時受雲的影響, 未用averted vision, 初步確定宇隆UHC 77mm濾鏡大約可以增加20%-30%觀測46P/Wirtanen的效率.

宇隆UHC 77mm濾鏡應該是屬於寬頻UHC濾鏡, 寬頻UHC濾鏡真的還滿值得在彗星上目視看看的.


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:51:21
2018 12 12前兩天半夜Nikon SP 18X70手持(躺睡袋+墊枕頭)成功解析雙子座20號星(20 Geminorum)

Two nights ago I easily found success in resorving 20 Geminorum by hand-holding a Nikon SP 18X70, Success rate is about 50-60%, much harder than I thought,considering its wide seperation of 20 seconds and 6.3/6.9 magnitude components.

尋找難易度: 15%左右非常容易, 雙子garma星附近
成功解析度: 50-60%有些許難度. 有些許難度這點有點奇怪, 尤其考慮到20秒的分開與不到一等的星等差
顏色: 兩顆亮度有些許差異橘黃??雙星
美麗度: 70%

第一張圖:6吋牛頓, 240x下的20 Geminorum. (Eric C, Graff)
第二張圖: 位於garma星右上方的最近的一顆6等星即是雙子座20號星(20 Geminorum)


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:54:34
2018 12 12前兩天半夜Nikon SP 18X70手持(躺睡袋+墊枕頭)成功解析船帆座的最亮星: 船帆座gamma(Velorum Gamma)

一般來說, 以沙鹿的光害中口徑雙筒只能解析最亮的其中兩顆, 這次是成功解析出三顆, 事實上根據以下的wiki在光害低的地方可以推估四顆很可能可以全部解析..........

尋找難易度: 0%-5%左右非常容易, 本身是船帆座最亮星
成功解析度: Gamma 1與Gamma 2 完全沒難度, 搞不好星
座鏡即可解析. Gamma 3有非常大難度的原因
是沙鹿的光害
美麗度: 100%(三顆星亮度, 顏色, 間距皆不同)

The brightest star in the constellation, Gamma Velorum, is a complex multiple star system. The brighter component, known as Gamma2 Velorum or Suhail, shines as a blue-white star of apparent magnitude 1.83.[4] It is a spectroscopic binary made up of two very hot blue stars orbiting each other every 78.5 days and separated by somewhere between 0.8 and 1.6 Astronomical Units (AU). The brighter component is a hot blue main-sequence star of spectral type O7.5 and is around 280,000 times as luminous, is around 30 times as massive and is 17 times the diameter of our Sun with a surface temperature of 35,000 K. The second component is an extremely rare example of hot star known as a Wolf–Rayet star, and is the brightest example in the sky. It has a surface temperature of 57,000 and is around 170,000 times as luminous as our sun, though it radiates most of its energy in the ultraviolet spectrum.[5] Gamma1 is a blue-white star of spectral type B2III and apparent magnitude 4.3.[6] The two pairs are separated by 41 arcseconds, easily separable in binoculars.[6] Parallax measurements give a distance of 1,116 light-years,[7] meaning that they are at least 12,000 AU apart. Further afield are 7.3-magnitude Gamma Velorum C and 9.4-magnitude Gamma Velorum D, lying 62 and 93 arcseconds south-southeast from Gamma2.


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:56:32
2018 12 16

Nikon SP 18X70手持(躺睡袋+墊枕頭)成功解析獵戶座HD 42111

獵戶座HD 42111
06h 08m 57.90s
+02° 29′ 59.0″
5.70
A3Vn

尋找難易度: 20%左右, 由玫瑰星雲, 至麒麟座8, 至cr 91, 至Orion HD 42111
成功解析難度: 30%
顏色: 主星灰藍, 伴星藍(非精密辨色, 憑個人感覺)
美麗度: 75%


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 14:58:30
雙眼天體望遠鏡: 一開始就被廠商與同好忽略............

https://youtu.be/jtuWIb7Dr8w


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 15:02:24
直視雙筒鏡組合(1)(上飛機組)

基本上我認為直視雙筒鏡組合要有三只:一只星座鏡+一只7-12倍雙筒+一只15-22倍雙筒(當然這三只在重量, 價格. 倍率, 色差, 星點, 修正, 視野, 沖氮,後續維修做工, 品牌, 甚至氣味上要考慮)

既然上飛機不訪考慮同級中最輕量化的APM 20X70 ED +PRO-OPTIC 11X70

APM 20X70 ED: 在重量, 價格. 倍率, 色差, 星點, 修正, 視野, 沖氮上面保持平衡, 在任何一點上面都沒有特別可以挑剔
以下是APM 20X70 ED的review
拉近感的诱惑-APM20X70望远镜入手体验http://www.bggd.com/bbs/forum.php?mod=viewthread&tid=406062

PRO-OPTIC 11X70: 這個倍率與口徑還是比10x50的規格好,畢竟出國去暗空看星還是11X70較優. 這只應該是7公分規格中有品質的雙筒中最輕的. 惟二缺點是視野小+非沖氮
以下是PRO-OPTIC 11X70的review
http://www.scopereviews.com/page3b.html

"The pain of poor quality lingers on long after the pleasure of low price wears off." These words echoed through my head as I placed my order for these 70 mm binoculars. I had planned to order the Orion Mini Giants ($269), but the low price of this pair caught me in a weak moment. As a result, I experienced "Buyer's Remorse" almost as soon as I hung up the phone. The binoculars arrived a few days later. They are well-constructed and apparently made in Japan. The lenses are multi-coated in a very dark green. There is no light cutoff from the BaK-4 prisms. The binos have a solid, serious feel to them, despite being even lighter (2.8 lbs) than the already lightweight Orion Mini Giants. Hmmm...Looking through the binos reveals a bright, sharp image, with very little softening or mushiness at the edges. The Pro-Optics have a smaller FOV than the Orions (4.0 deg vs. 4.5 deg) but they're sharper across what field is there. After a few tense initial minutes, I relaxed. Hey, these are good binos! They gave very pleasing views of the Pleiades, M42, and the Double Cluster. Sweeping through the Cygnus Milky Way is a lot of fun. These are going to come in handy for sweeping fields as I work my way through the Herschel 400. What's more, they are light enough to hand hold for several minutes at a time. The binos come with the standard battery of accessories I never use - two straps, a cheap hard case, and a piece of cheese cloth. There are two lens caps for the eyepieces and one huge cap for both objectives, which is "back- wards" and the only fault I can find with the binos. These Pro Optic binoculars are cheap, and they're good. Highly recommended!


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 15:05:21
直視雙筒鏡組合(2)(廣角組合)

直視雙筒鏡組合之廣角組合Nikon 18x70 sp+Nikon 8x30 eii, 兼具廣角, 經典, 做工, 輕便四項. 還有Nikon 18x70 sp+Nikon 8x30 eii這兩只看星表現極度相似(如下review所示), 絕配😊.

<<Both binoculars were surprisingly similar instruments in their overall feel😊>>,with their biggest differences being their size and weight, related to their apertures of 30mm vs 70mm, magnification, 8x vs 18x and focusing, CF vs IF.

What struck me most however, were their similarities. Even the coatings looked like they came from the same batch, although they were made and bought new almost a decade apart. Very enjoyable instruments side by side. One around my neck on it's strap, the other on my Gitzo 224 tripod with Manfrotto HDV501 fluid head, although sometimes held by hand, as I also did to compare the "feel" of their views and eye relief last night. Both wonderful instruments. One being outstanding for observing hand held, the other shining on a sturdy tripod.

For observing the night sky, the 18x70 once again made clear <<what formidable instruments they are😊>>. Their views of the night sky never cease to amaze me.

某同好的心得 : Nikon 18x70是我買過最值得的望遠鏡之一(出勤率超高),它的重量比一般7公分級雙筒還要略輕(2050g),配重上很適合手持,最難得的是它有72度的廣角視野,使它更能發揮雙筒身歷其境的效果(這很重要! 會讓你有拉近的錯覺)。而且在換上橡膠眼罩後,既使戴上眼鏡也能輕易看到完整視野。唯一讓人挑剔的是色差校正不如市面上的ED鏡,但如果不是在白天或是月面觀測使用,幾乎無法察覺。所以Nikon 18x70是屬於黑夜的,我把它當成快速Survey星雲星團的利器。如果是月面觀測的話,我比較喜愛用APO單筒望遠鏡加上雙目,這才是它最擅長的領域。附帶一提,Nikon 8x30 eii真的好美型喔,要不是良視距太短不適合我,不然拿來看舞台表演應該很棒,但如果是輕量級的天文觀測,我會更推薦用4公分左右的廣角雙筒。


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 15:11:44
直視雙筒鏡組合(3)(經濟組合)

Nikon Action Exteam 8x40 +Lunt 16x70

低倍: 選擇性應該滿多的. Nikon Action Extreme系列8x40/10x50/12x50三只較好.
高倍: Lunt 16x70與Fujinon 16x70 FMT-SX比有價格, 重量, 眼距三大優勢. CN review其實考慮價格以後Lunt壓倒勝. 另外
可參考http://www.binocularsky.com/reviews/Lunt_16x70.pdf


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 15:23:30
直視雙筒鏡組合(4)(雙星組合)

低倍: Cannon IS 10x42. 開啟穩像至少有200多組雙星可觀測
(根據CN, 只是不知是南半球還是北半球還是環遊世界的觀測者)

高倍:首選Takahashi 22x60 apo(顏色最美, 出瞳比70mm級雙筒小但有效集光達65mm, 倍率最大, 背景最暗)
次選:WO 22X70 APO(有效集光力, 倍率)
再次選:APM 20X70 ED或NIKON SP 18X70






主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 15:36:11
Messier 50附近Lunt 16x70比較有看頭的天體: 麒麟座NGC2343

附近不少天體掩沒在沙鹿的光害下, 很難判讀出來





主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 15:44:57
大小懸殊的40mm目鏡, 大的是Meade SWA 40mm 70度目鏡(取自CN)


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 16:26:54
幼稚園等級難度的手持雙星, 10X??以上雙筒一定要試

Nikon SP 18X70手持(躺睡袋+墊枕頭)成功解析雙魚座的亮星:
雙魚座Psi1 Piscium(Psi1 Psc, ψ1 Piscium, ψ1 Psc)

尋找難易度: 10%-15%左右非常容易
成功解析度:  0%-5%(ψ1Psc A 與ψ1 Psc B 完全沒難度, 幼稚園等級難度)
顏色: 藍白
美麗度: 85%(兩顆星亮度, 顏色超相近.......炯炯有神的一對藍白眼睛橫空出世於黑暗背景中)

Psi1 Piscium (Psi1 Psc, ψ1 Piscium, ψ1 Psc) is binary star in constellation of Pisces. It is approximately 280 light years from Earth, based on its parallax.[1]

The two components of Psi1 Piscium are both A-type main-sequence stars.[3][5] The primary has an apparent magnitude of 5.273, while the secondary is slightly dimmer, with an apparent magnitude of 5.455.[2] The primary itself is a close binary, with two A-type stars that orbit each other every 14.44 years.[3]

Psi1 Piscium is moving through the Galaxy at a speed of 22.5 km/s relative to the Sun. Its projected Galactic orbit carries it between 22,800 and 24,300 light years from the center of the Galaxy.[8]


主題: 回覆: 沙鹿的星空
作者: yao2019-01-09 16:37:42
8X手持雙筒(朗峰平場pro 8x42)可分解的雙星: 船帆座gamma(實際上是四合星)

不但可以分解, 而且也能看出gamma 1與gamma不同的顏色