7月尾澳洲Ayers Rock之旅

[willis]

I don't really see any noise problem in the tracked photos, even after vigorous stretching when playing them around in photoshop.
Which one are you especially concerned about?

I don't mean it has noise problem. The noise was low already. But I expect the noise should be much lower than normal. My thought is that it was winter in Australia and the location is not close to the sea. So I suppose the temperature was low at night. That's why I asked u about the temperature. (Note: I haven't been to Australia)

[willis]

The mosaic is spectacular!

[PaulNg]

The sensor temperature was around 15-21 degrees, air temperature was from sunset at around 20 to a few degrees at twilight.

Thanks for you appreciation!

[PaulNg]

Last one

天蠍座心宿二附近區域

Optics: Borg 125SD, 7870 0.7x reducer
Mount: Takahashhi EM11
Camera: Canon EOS 6D modified, ISO800
Exposure: 上下左右四幅拼圖, 各含12x300sec (1 hrs)
Guiding: Lodestar, 50/200 guidescope, PHD (dithering enabled)
Softwares: Photoshop, DSS, Pixinsight, Registar, BackyardEOS

[社長]

請問Paul你此行共用多少套器材拍了多少張照片?

你的拍攝目標中，有些我在西藏是拍得到的，跟澳洲比缺乏地利，但西藏的固定器材跟我帶流動器材去澳洲拍，還是前者較大利，所以我想，若到澳洲拍的話，會集中在南天極的直徑80度範圍內選幾個重點目標拍好他

[PaulNg]

3個晚上
主炮Borg125SD, EM11, 6D, 成品6張, 其中一張2x1拼圖, 一張2x2拼圖
Toast Pro, 24-70, 5D2, 旁邊玩玩而已，三張，跟一個學生一起用
學生們自己玩FSQ106，EM11, 600D, 我偷時間拍了一張.

很多時間花在溫度變化的重新對焦上， 由其是拍完一個小時候才發現...

[willis]

The sensor temperature was around 15-21 degrees, air temperature was from sunset at around 20 to a few degrees at twilight.

Thanks for you appreciation!

The modifications of ur camera was not the simple one, just replace the filter, there was temperature sensor on it. Anyway, the temperature change at night was significant. On the other hand, the temperature was not as low as I guess.

[willis]

The Rho Ophiuchi is stunning! Is it the mosaic was done by PS? I guess once u fine tune the 7080 and 125SD, the stars performance at full frame corneas will be much better. That is the full frame challenge which most people give up. Only a few serious astrophotographers take it seriously. I once encountered... very sky time consuming...

[PaulNg]

The modifications of ur camera was not the simple one, just replace the filter, there was temperature sensor on it. Anyway, the temperature change at night was significant. On the other hand, the temperature was not as low as I guess.

It is a simple modification, but BackyardEOS can read the temperature on the camera's sensor.

The Rho Ophiuchi is stunning! Is it the mosaic was done by PS? I guess once u fine tune the 7080 and 125SD, the stars performance at full frame corneas will be much better. That is the full frame challenge which most people give up. Only a few serious astrophotographers take it seriously. I once encountered... very sky time consuming...

The raws were calibrated in DSS, then Registar for mosaic morphological transform, finally combined in PS and final retouch.
I suspect if i use other setups, there will be much less trouble in adjusting the image plane (mostly non adjustable). Anyway, need to have a clear sky to test things out.

[社長]

3個晚上
主炮Borg125SD, EM11, 6D, 成品6張, 其中一張2x1拼圖, 一張2x2拼圖
Toast Pro, 24-70, 5D2, 旁邊玩玩而已，三張，跟一個學生一起用
學生們自己玩FSQ106，EM11, 600D, 我偷時間拍了一張.

很多時間花在溫度變化的重新對焦上， 由其是拍完一個小時候才發現...

謝謝，亦即和我的想法差不多，若用單反及配一台較大光圈主鏡的話，三晚拍好三個目標，或許多加一兩個較速成的較為合理，或許加個星野赤道儀，拍幾星野照。

或許，也只是或許，我去一次澳洲便夠，赤緯負50度以上的我留在西藏拍。

[社長]

The modifications of ur camera was not the simple one, just replace the filter, there was temperature sensor on it. Anyway, the temperature change at night was significant. On the other hand, the temperature was not as low as I guess.

It is a simple modification, but BackyardEOS can read the temperature on the camera's sensor.

我的5D Mark II是Hutech modified的，也裝有温度計，最後發現沒有晶片恒温的話，其實暗場也不可靠，因為晶片温度變化根本是很複雜的。另一方面，在西藏零下廿度拍過，在台灣零上數度拍過，也有在盛夏時拍，其實要拍好片往往要往山上跑，氣温也不會高到哪裡去，所以不用太介懷訊噪，所以我的看法是用單反不如瀟酒點，要追求完美的，還是用冷凍CCD算了。

[willis]

Paul,
Did u use any filters in ur images?
Willis

[PaulNg]

Nope, none at all.

[willis]

Excellent sky!

[社長]

看到你使用的軟件有點好奇，請教一下，為何不單靠MaximDL拍攝(有Dithering)，然後用PixInsight處理便算?

P.S., 論Dithering我較喜歡TheSky用的spiral dithering，MaximDL只有Random的不太好。

我沒有買MaximDL, 可能在玩單色CCD的時候才用。
本身用PHD 做guiding， 可以和BackyardEOS做溝通自動化dithering.
以上的程式就是BYEOS要買而已, 並且相當好用。

為準備今晚月食，發現有一個小功能MaximDL未能做到，我花US50買了BackyardEOS Premium，的確好用。

[PaulNg]

The double-fan diffraction and CA were outside the APSC region. This was exactly what I encounter before. After fine tuning for full frame, moving it "about 4mm" further, both double fan & CA will be improved. In my case, matching 7870 and APM 80/480, the stars at corners are not perfect. However, the result is acceptable. Maybe Borg reducer works perfectly with Borg objectives.

That gave me so much hope for me willis. Do you have any photos taken before and after your adjustment?

[willis]

Let me check.