沙鹿的星空

[yao]

Collinder 140

[yao]

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

[yao]

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)

[yao]

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😊

[yao]

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/

[yao]

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.

[yao]

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)

[yao]

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.

[yao]

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%

[yao]

雙眼天體望遠鏡: 一開始就被廠商與同好忽略............

https://youtu.be/jtuWIb7Dr8w

[yao]

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!

[yao]

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。

[yao]

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

[yao]

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

[yao]

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