大屯鞍部的冬季銀河

初五台北天氣非常好，於是上山開電、看星星。剛好又遇到文正兄帶著他的eVscope2也上來。

這陣子都帶Pentax MS-3單軸赤道儀（改赤經加導星埠），使用MGENII的內建漂移法修正極軸功能對極，由於已經熟悉了，所以這次很快就修到顯示誤差在1.5’，750mm 焦長單軸導星單張3分鐘仍相當圓，符合預期，曝35張只有三張離群較高，平均roundness約在0.91算是很優，不過我只帶了三波長窄頻NB1濾鏡，所以我的全光譜改機只能先拍一下窄頻，改天再拍正常L濾鏡。

遠方小觀音山電台最近出現的一盞白光廣場燈大約八點就關閉了，但月亮要到接近午夜才下山，所以可以一邊吃著泡麵先欣賞月光，在月亮下山後也用ASTROTRACER拍了幾張星景跟冬季銀河（使用未改機K3II，下次再找機會用改機拍）。

這晚鞍部的暗空狀況算是正常的良好值 ，午夜後天空就進入了最佳的狀況（午夜SQ20.1）。

不過因為不想要操勞，所以我們約兩點多都下山回家睡覺了，下山前遇到一位在學學生才剛上來準備要爬上大屯山去拍日出銀河。

也重新接合了一張去年拍的銀河。

The weather in Taipei was very good on the fifth day of the Lunar New Year, so I went up the mountain to 開電（It symbolizes the first time in a year that you are using your work tools） and go stargazing. I happened to meet my friend Wen Zheng who was also going up with his eVscope2.

I have been using the Pentax MS-3 single-axis equatorial mount (modified with a RA guiding port) recently. I used the built-in drift method of MGENII to correct the polar axis. Since I am already familiar with it, I quickly adjusted it to a display error of 1.5'. The 750mm focal length  single shot is still quite round at 3 minutes, which meets expectations. and the average roundness was about 0.91, which is considered very good. However, I only brought  NB1 filters, so my full-spectrum modified camera K5 can only shoot narrowband first, and I will shoot normal L filters another day.

The white floodlight at the 小觀音Mountain Radio Station in the distance was turned off at around 8 o'clock, but the moon would not set until close to midnight. So I could eat instant noodles while enjoying the moonlight, and after the moon set, I used the ASTROTRACER to take a few pictures of the starLandscape and the winter Milky Way (using the unmodified K3II, I will find another opportunity to use the modified camera to shoot next time).

The dark sky conditions at the saddle this night were considered normal and good. The sky was at its best after midnight (midnight SQ20.1).

However, we didn't want to overwork ourselves, so we all went down the mountain  at around 2:30. Before going down the mountain, we met a student who was just going up to climb 大屯山主峰 to shoot the sunrise and the Milky Way.

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Pentax K3II, DA10-17

winter milky way of 大屯鞍部  was combined with 4 frames, and each frame was stacked with 10 sub frames (40sec each sub fame), 

registar, Potoshop