旅攝DSO遺照集 -- M20
Re: 旅攝DSO遺照集 -- Veil complex again
12. Veil complex
Taken with EF70-300mm F4-5.6L + 100Da in Coonabarabran in 2013 @90mm F5.6
6x360s @iso800, autoguided with Vixen GP mount
Stacked in DSS with darks calibrated only
Processed in PI and PS
Taken with EF70-300mm F4-5.6L + 100Da in Coonabarabran in 2013 @90mm F5.6
6x360s @iso800, autoguided with Vixen GP mount
Stacked in DSS with darks calibrated only
Processed in PI and PS
Re: 旅攝DSO遺照集 -- M83
13. M83
After combining RGB channels in PI and using STF to stretch the image, something looks very weird. Could you find it?
Taken with Vixen VSD100F3.8 astrograph + Atik 383L+ mono CCD in Australia in 2015 @380mm F3.8
R=G=B=6x360s, autoguided with Vixen SX2 mount
Stacked in PI with darks and bias calibrated only
After combining RGB channels in PI and using STF to stretch the image, something looks very weird. Could you find it?
Taken with Vixen VSD100F3.8 astrograph + Atik 383L+ mono CCD in Australia in 2015 @380mm F3.8
R=G=B=6x360s, autoguided with Vixen SX2 mount
Stacked in PI with darks and bias calibrated only
- littleming
- 夸克星
- 文章: 3525
- 註冊時間: 週三 14 11月, 2012 16:23
- 來自: chaos
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Re: 旅攝DSO遺照集 -- M83
If interested, please check below for some print screen images, processed M83 done with DBE and PCC tools, and a crop from B channel after STF
Color calibrated with PCC
Histogram after stretching
Re-processed M83 with DBE and PCC tools in PI
A crop from B channel after STF
Color calibrated with PCC
Histogram after stretching
Re-processed M83 with DBE and PCC tools in PI
A crop from B channel after STF
Re: 旅攝DSO遺照集 -- M20
14. M20
A data combination of L channel taken with Vixen VSD100F3.8 + Atik 383L+ mono in 2015 and Vixen ED81SII + 100Da in 2017, both in Australia
A data combination of L channel taken with Vixen VSD100F3.8 + Atik 383L+ mono in 2015 and Vixen ED81SII + 100Da in 2017, both in Australia
- littleming
- 夸克星
- 文章: 3525
- 註冊時間: 週三 14 11月, 2012 16:23
- 來自: chaos
- 聯繫:
Re: 旅攝DSO遺照集 -- M20
Supplementary information for your interest related to the above M20 image.
To me, the trip down to Australia in 2016 for astronomy was one of the saddest experience up to now. That was my 1st time to bring a cooled CCD camera down south. Though there is much security light in the holiday park, the milky way is still very bright as seen with naked eyes. So, I did have very high expectation on all the data collected by the cooled CCD camera after the trip. It was true to L, R and G channels, except B channel.
Why? Because I brought a manual filter wheel. The filters were changed by pressing a botton on the controller. Before the trip, I had used the manual filter wheel a few times and the results didn't show any issue. But when being back home after the trip, I tried to combine the R, G, B channels of some objects captured in the trip. All looked very weird. By comparing to those objects taken in HK, I was suspected the B channel data taken in the trip was not blue, but Ha !!! That is really a nightmare to me.
So I don't process those data captured in the trip and let them have stored in the HD for years. Recently, I am thinking how to give these data with life again? So, starting from this M20 wide field by combining those color data taken with 100Da into the L channel.
As the imaging focal length for L channel is 380mm while that for the color image is 624mm, it should not be correct to make such a data combination. Moreover, the stars were elongated in the color image due to wind issue when I took this object in 2017. But I cannot go back to shoot M20 again with the astrograph VSD100F3.8. The astrograph had been sold to my friend. So, no choice to me and then took such an attempt on this object.
Below images show the L channel and color one for your reference, both with histogram stretching in PI.
To me, the trip down to Australia in 2016 for astronomy was one of the saddest experience up to now. That was my 1st time to bring a cooled CCD camera down south. Though there is much security light in the holiday park, the milky way is still very bright as seen with naked eyes. So, I did have very high expectation on all the data collected by the cooled CCD camera after the trip. It was true to L, R and G channels, except B channel.
Why? Because I brought a manual filter wheel. The filters were changed by pressing a botton on the controller. Before the trip, I had used the manual filter wheel a few times and the results didn't show any issue. But when being back home after the trip, I tried to combine the R, G, B channels of some objects captured in the trip. All looked very weird. By comparing to those objects taken in HK, I was suspected the B channel data taken in the trip was not blue, but Ha !!! That is really a nightmare to me.
So I don't process those data captured in the trip and let them have stored in the HD for years. Recently, I am thinking how to give these data with life again? So, starting from this M20 wide field by combining those color data taken with 100Da into the L channel.
As the imaging focal length for L channel is 380mm while that for the color image is 624mm, it should not be correct to make such a data combination. Moreover, the stars were elongated in the color image due to wind issue when I took this object in 2017. But I cannot go back to shoot M20 again with the astrograph VSD100F3.8. The astrograph had been sold to my friend. So, no choice to me and then took such an attempt on this object.
Below images show the L channel and color one for your reference, both with histogram stretching in PI.
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