香港天文論壇

It was so clear, sunshine, and the sky was so blue in the morning 2 days ago. So, went to PTC to go on gathering the photon of M33. However, bad luck again. I arrived there together with cloud too and then left with much frustration. Tried the correction exposure ratio for each RGB channel but not s...

Is it still worthy for combining L channel data into this RGB M33 ?

Taken with Vixen SD103S + HD reducer kit + 1600 MM-C @624mm F6.1 on Oct 30th
R=G=B=8x180s

Old film image, new processing tool Taken with Vixen DED108SS astrograph + kodak E200 emulsion in 2007, manually guided with Vixen GP mount Preprocessed in PI with DBE, BackgroundNeutralization, ColorCalibration, Histogram, Curve, MLT., and then final touch in PS There should have no noise in a film...

What will be happened when PCC in PI is applied on a film image for calibrating the color of stars?

Any thoughts about PCC could come out ?

Film image taken with E200 emulsion and Vixen DED108SS astrograph in Coonabarabran in 2007.

好揀唔揀，揀著個爛燈盞 (廣東俗語)

原本前晚都可取得 permit 去 PTC，但想多一點拍攝時間，最後選擇昨晚出擊，結果.......

透明度低左
高層雲多左
其後更吹勁風.....

When the light pollution is so severe... the seeing was not so good... the ground kept vibrating.... Moreover the sampling as way over so much.... You might imagine what result would come out !!!!! LRGB image taken with VC200L @ f.l.=1800mm, F9 at my observation site in YL last night @ sampling = 0....

實在有太多data閒置不理，偶然找到就隨意處理

Taken with Vixen 20cm F4 牛牛 + corrector PH @PTC
Ha channel = 5 x 360s

曾嘗試在PI內用 HDRComposition 和 HDRMT 玩玩 HDR，但仍未掌握好，於是改在PS內玩玩，看看效果怎樣，初步掌握到一點點。

帶 8" 牛牛上山、上飛機去攝星，不是沒可能，只是要多付很多＄＄和體力。但帶 6" 牛牛，相對地，可能性就高得多。當然，赤道儀就不能太重型了。待這支 6" F4 牛牛 OTA 再優化後，我就會帶這支自己組裝的 6" F4 牛牛 + Vixen AP mount 上山、上飛機去攝星。 這支 6" F4 牛牛的主鏡不是一塊優質拋物面鏡，但我要求不高，攝星效果 acceptable to me，一分餞一分貨也。 Taken with this 6" F4 newtonian + MPCC3 + LPS + 100Da @PTC in 2016 Stack of two sets of exposur...

2016年11月，往台灣攝星及首次出席翠峰星趴，但天意弄人，不斷下雨+密雲，3晚行程，只得約1小時拍攝時間！！！

在PI內重新處理
Taken with !00Da + EF180mm F3.5L macro @F3.5
Total exposure = 11x360s @iso800
Autoguided with Vixen AP mount @photoguider mode

只可惜鏡頭質量不佳(天文攝影領域)，唯有12月中(2018)用Vixen Baby Q 再補拍過。

Thanks 大黃傻貓GARFIELD , willis and anyone.

若以0(完全沒光害)-10(極嚴重)來表示某地點的平均光害指數(LPI)，我會評PTC的LPI=6 (屬中度以上)。

在光害中度以上的條件下，要拍出M77的外圈旋臂，很不容易呢！

用4"口徑和800mm左右的焦距來打此NGC天體和其附近的galaxy group，真的很不夠 ＂力＂。看來要出動大牛牛了。

Taken with Vixen SD103S apo + HD flattener + 1600MM-C @PTC last Friday.
R=G=B=6x300s @-15C without any flat calibrated in PI

One more taken with Vixen Baby VSD @PTC at 20181005

20x120s @iso1600, autoguided with Vixen AP non-goto mount
Color balanced with PCC in PI and final touch in PS

上星期五晚再出擊PTC，今次走運，雖仍有煙霞，但整夜沒雲，可讓Baby VSD盡享星光。

Taken with Vixen Baby VSD + HD flattener + Kenko light pollution filter + 100Da
27x180s @iso1600,
Autoguided with Vixen AP non-goto mount
Stacking and color calibration with PCC in PI