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Hello Astronomers,

My latest image, The Sculptor Galaxy, also known as the Silver Coin or Silver Dollar Galaxy, NGC 253, an intermediate, starburst spiral galaxy in the constellation Sculptor, about 11.4 million LY away, undergoing a period of intense star formation.

 

This photo was imaged in natural color through my 8" Celestron SCT at 2032mm focal length using my astro-modded and cooled canon 40D DSLR and tracked with a CGEM mount.

I imaged this galaxy when the moon was nearly at first quarter and in the same general direction as the galaxy, so I used the Neodymium filter (AKA Moon and Skyglow filter) instead of the UV/IR Cut filter to try and control the moon glare, I think it worked.

Total exposure time was 5 hours 41 minutes.

 

Clear Skies,

MG

 

NGC253 RGB F10 Dec2019 Frm.jpg

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Terrific, I love all those dust lanes.  The CGEM has done a good job taming the focal length.

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Very nice picture indeed, I did not know this galaxy, amazing details !

What software did you use to frame your picture and write your signature and info on the target ? It looks quite nice and adds a nice touch when sharing with others :) 

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On 07/12/2019 at 13:23, Vox45 said:

Very nice picture indeed, I did not know this galaxy, amazing details !

What software did you use to frame your picture and write your signature and info on the target ? It looks quite nice and adds a nice touch when sharing with others :) 

Thanks... The original framing template was generated by an action pack called "Astrophotograhy Tools" for Photoshop.  I modified it slightly for my liking and use it for my DSO images.

Gives a basic description of the object, such as the name, ID and date imaged along with my watermark.

 

I do recommend the action pack as it does have some useful and effective actions/features.

 

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45 minutes ago, assouptro said:

Hi MG 

Good job! 
Can I ask, what were the length of the subs? 
thanks for sharing 

Bryan 

Hello Bryan,

First I started imaging the galaxy through the UV/IR filter and ended up with subs 8x90s, 7x150s, 7x300s, 6x450s, 6x600s but they were on the overexposed side. The following night I used the Neodymium filter, AKA " Moon & Skyglow" filter instead of the UV/IRCut filter and did 1x900s, 1x660s, 2x600s, 11x540s, 1x420s, 4x300s @ ISO1600, totalling exposure time of 5h 41m & 30s.

I did stack all subs to process the final image.

 

MG

 

 

 

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1 hour ago, MarsG76 said:

Hello Bryan,

First I started imaging the galaxy through the UV/IR filter and ended up with subs 8x90s, 7x150s, 7x300s, 6x450s, 6x600s but they were on the overexposed side. The following night I used the Neodymium filter, AKA " Moon & Skyglow" filter instead of the UV/IRCut filter and did 1x900s, 1x660s, 2x600s, 11x540s, 1x420s, 4x300s @ ISO1600, totalling exposure time of 5h 41m & 30s.

I did stack all subs to process the final image.

 

MG

 

 

 

Thanks for the reply MG

Thats a lot of subs with a varied time scale and would present a challenge Calibrating and stacking (for me, that is)

Did you match all those lights with darks? 

cheers

Bryan

Edited by assouptro

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4 hours ago, assouptro said:

Thanks for the reply MG

Thats a lot of subs with a varied time scale and would present a challenge Calibrating and stacking (for me, that is)

Did you match all those lights with darks? 

cheers

Bryan

The more subs the better the SNR will be in the final stack, so I try to get as many as possible.

I expose various length subs simply to expose for the brighter and dimmer parts of the object being imaged. When all of these subs are stacked into a 48 bit image, than the data is embedded within the 48bit stack but the levels are displayed linearly and I'm able to use levels to stretch out the image with great control on both the brighter and dimmer parts of the object.

When it comes to preparing the subs for stacking, I only use 20xBIAS frames and 20X Flats taken through the corresponding filters that were used for the subs. I do not use darks at all.... when I tried using darks, the result was worse, but this could be that I'm a DSLR imager and I can't exactly control the sensor temperature so no dark frames for me.

What I do is I use a 2 pixel at threshold 30 Dust and scratches filter on each sub after it was converted from the CR2 raw to 16 bit TIFF and pre process them in Nebulosity 3.3. Stacking is also carried out in Nebulosity 3.3, and it's remarkable easy to do, even then the subs are dithered, where my imaging is always dithered.

One thing I plan to improve next is the crispness of my images at 2032mm focal length.

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3 hours ago, tooth_dr said:

What an image MG. Fantastic! The 40d is formidable 

Yeah, I like my 40D.. makes me think that I do not need a "dedicated" astrocam.

Edited by MarsG76

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On 07/12/2019 at 08:55, MartinB said:

Terrific, I love all those dust lanes.  The CGEM has done a good job taming the focal length.

One thing I plan to improve next is the crispness of my images at 2032mm focal length.

The 40D already being 1.16"/pixel on the C8 at 2032mm fl and consistently tracking at RMS below 1", it might not make a difference and this might simply be the limit of my equipment???

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3 hours ago, MarsG76 said:

One thing I plan to improve next is the crispness of my images at 2032mm focal length.

The 40D already being 1.16"/pixel on the C8 at 2032mm fl and consistently tracking at RMS below 1", it might not make a difference and this might simply be the limit of my equipment???

The clarity and sharpness in your image is better than anything I managed when I was imaging with DSLR  and my 12 inch SCT at 3048mm Fl  sometimes with a 6.3FF/FR, I was always trying to get a sharper image. 
I considered using adaptive optics device but I never took the plunge and instead I bought a second hand Atik 314l+, I was astounded by the difference in clarity and detail and wondered why I had left it so long (10 years with DSLR) Although it has presented many more challenges with filters, filter wheels etc It was a bit like starting again from scratch, but I don’t think I could go back unless I’m travelling with a portable setup (which I can’t afford to do since buying all the extras!)
All I need now is clear skies, which Seem much more illusive  

Cheers 

Bryan 

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On 05/12/2019 at 18:45, MarsG76 said:

Hello Astronomers,

My latest image, The Sculptor Galaxy, also known as the Silver Coin or Silver Dollar Galaxy, NGC 253, an intermediate, starburst spiral galaxy in the constellation Sculptor, about 11.4 million LY away, undergoing a period of intense star formation.

 

This photo was imaged in natural color through my 8" Celestron SCT at 2032mm focal length using my astro-modded and cooled canon 40D DSLR and tracked with a CGEM mount.

I imaged this galaxy when the moon was nearly at first quarter and in the same general direction as the galaxy, so I used the Neodymium filter (AKA Moon and Skyglow filter) instead of the UV/IR Cut filter to try and control the moon glare, I think it worked.

Total exposure time was 5 hours 41 minutes.

 

Clear Skies,

MG

 

NGC253 RGB F10 Dec2019 Frm.jpg

Amazing. Most people say not to even bother trying to image with a C8, but your images show that it's capable of so much in the right hands. 

As a fellow C8 owner, i'm definitely feeling some 'sky & mount' envy right now! lol. 

Great image. 

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2 hours ago, Xiga said:

Amazing. Most people say not to even bother trying to image with a C8, but your images show that it's capable of so much in the right hands. 

As a fellow C8 owner, i'm definitely feeling some 'sky & mount' envy right now! lol. 

Great image. 

I heard that too, but I always wondered "why?"... I think it's because of the native focal length and the difficulty of accurately tracking at such high magnifications. But the CGEM does track at accuracy at below the "/pixel res so this detail might be the limit of my sky & camera.  

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12 hours ago, assouptro said:

bought a second hand Atik 314l+,

So did the Atik improve on the clarity & resolution when comparing to the DSLR at the same focal length?

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14 hours ago, MarsG76 said:

So did the Atik improve on the clarity & resolution when comparing to the DSLR at the same focal length?

It did.

I’ll try and find some comparable photos of the same object with the same optical system so you can judge yourself. 

I’ll look through my files this weekend 

Cheers 

Bryan 

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17 hours ago, lux eterna said:

Great result ! It´s hard to believe you had F10 and so little integration time. Nicely processed.

Ragnar

It's a quite bright object, there were objects where I spend more than 25 hours, NGC300 is one, and narrowband total exposure in excess of 56 hours... the fighting dragons of Ara, both at F10.

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  • Similar Content

    • By MarsG76
      The Sculptor Galaxy, also known as the Silver Coin or Silver Dollar Galaxy, NGC 253, an intermediate, starburst spiral galaxy in the constellation Sculptor, about 11.4 million LY away, undergoing a period of intense star formation.
      This photo was imaged in natural color through my 8" Celestron SCT at 2032mm focal length using my astro-modded and cooled canon 40D DSLR and tracked with a CGEM mount.
      I imaged this galaxy when the moon was nearly at first quarter and in the same general direction as the galaxy, so I used the Neodymium filter (AKA Moon and Skyglow filter) instead of the UV/IR Cut filter to try and control the moon glare, I think it worked.
      Total exposure time was 5 hours 41 minutes.
       
    • By hjw
      I finally got around to get myself a 8" f/5 Newtonian with a GSO coma corrector and had my first go at the Sculptor galaxy (NGC253). The picture was taken from 33 frames, 180sec at ISO800. First off, I was impressed with how much light the scope collects compared to the ED80. I could already see the dust lanes on the individual frames. I noticed that I still had coma in the corners of the full image and searching the internet found that the coma corrector requires a 15-20mm spacer to work with DSLRs - Bummer! The stars are wider than what I am used to. According to the Bhatinov mask, focus should have been pretty spot on but compared to the ED80 my star width went from 3.6 to 5.6 pixels. Is this due to the missing spacer ring, still not perfect focus or that my mount (HEQ5) is struggling with the weight, or do I have to live with it? Just trying to understand what is normal for a reflector and what I can improve.
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      On the 23rd of September 1783, sitting before her telescope in the field behind the house she shared with her brother William at Datchet, near Slough in the south of England, Miss Caroline Herschel "swept" the sky searching for new comets and never before seen star clusters and nebulae.   On this occasion, way down in the sky, not far above the Southern horizon, in an area of the southern sky that Nicolas de Lacaille had called the “Apparatus Sculptoris” or “the sculptor’s studio", Miss Herschel saw and noted down a very bright and large nebula where one had never before been recorded.  This event was later recognised by her brother, Sir William Herschel, as the discovery, by Caroline Herschel, of the nebula he listed in his catalogue as H V.1.   In later years, her 'beloved nephew', Sir John Herschel, William's son, would record this 'nebula' as entry # 138 in his General Catalogue of Nebulae and Clusters of Stars ( eventually becoming the 253th entry in the New General Catalogue, NGC 253 ).
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      ===============================================
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      .........
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