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Lynds Dark Nebula LDN1251


peter shah
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LDN1251 in Cepheus, Imaged from Spain with the Tak Epsilon 180ed. I've just fitted a new ZWO ASI2600MC to it and this is the first image. 96x 300s exposures, 8hrs total. I really like this chip!. 

Plagued with satellite trails I was still able to use every exposure.  The shear number of subs gave a good rejection in the stack with no signs of satellites in the final image even after  such an aggressive process.  

Processed with Pixinsight and Photoshop

Thanks for looking

Peter

 

LDN1251.jpg

1251 Satellite rejection.jpg

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7 hours ago, peter shah said:

LDN1251 in Cepheus, Imaged from Spain with the Tak Epsilon 180ed. I've just fitted a new ZWO ASI2600MC to it and this is the first image. 96x 300s exposures, 8hrs total. I really like this chip!. 

Plagued with satellite trails I was still able to use every exposure.  The shear number of subs gave a good rejection in the stack with no signs of satellites in the final image even after  such an aggressive process.  

Processed with Pixinsight and Photoshop

Thanks for looking

Peter

 

LDN1251.jpg

1251 Satellite rejection.jpg

 

Excellent image Peter. The dark skies really bring out the contrast in these faint dark nebula. I just did a quick count on the satellites trails in the image, I reckon about 30. Roughly 1 every 3 images, not bad going. 😁

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6 minutes ago, ApophisAstros said:

Hi peter , what an image,

I would be interested in one of those subs unprocessed as thats quite a long length given its CMOS , i have a older lower end Cmos OSC QHY183mc and wanted to try longer exposures.

Roger

300s is as long as I go on this camera and only for darker object such as this. The Kepler4040 however is completely different, the longest I do on that is 180s for dark or narrow band objects. There is very little point on cmos to go any longer unless you lower the gain...but lowering the gain gives a lower signal to noise, so why would you do that...more noise and less signal make no sense and you may as well be using a CCD. 

I think the problem is CCD has been in the forefront of imaging for so many years and so it's difficult to get away from the older ways of longer exposures...... The benefit of short exposures is the more frames the better the rejection algorithm works and further lowing the noise floor.....

 

Here's what the raw 300s sub looks like, with an auto stretch and debayer of course.

1 hour ago, AstronomyUkraine said:

 

Excellent image Peter. The dark skies really bring out the contrast in these faint dark nebula. I just did a quick count on the satellites trails in the image, I reckon about 30. Roughly 1 every 3 images, not bad going. 😁

You need to have dark skies to be able to process down close to the noise floor for the real faint stuff. There's a few trails god bless Musk!

1251 unprocessed.jpg

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11 hours ago, ApophisAstros said:

I Was thinking about musks sats and if the satelites are spininng mainly to cover the populated part of the globe ie the internet so if you are on either pole would you be able to miss a lot ot satelites when imaging ? Purely academic question of course.

Roger

To be honest there is going to be so many that I think there is no escape from Musks vandalism.

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Great image Peter.  I am very envious, this is a target I have been wanting to get for some time, but need to be at a campsite in darker skies at the right time.  What Bortle scale is the Roboscopes remote location, I bet it's less than Bortle 4.

 

As for those satelitte trails, words fail me that the sky can be allowed to be polluted by the likes of Musk and Amazon. 

 

Carole 

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2 hours ago, Carastro said:

Great image Peter.  I am very envious, this is a target I have been wanting to get for some time, but need to be at a campsite in darker skies at the right time.  What Bortle scale is the Roboscopes remote location, I bet it's less than Bortle 4.

 

As for those satelitte trails, words fail me that the sky can be allowed to be polluted by the likes of Musk and Amazon. 

 

Carole 

Thanks Carole.....To be honest I too have been wanting to get this one for ages...I've more data coming from this object on some of the other scopes...I want to compare the difference...... Bortle at the site is 2-3 so pretty dark.....Those satellite trails are sickening!!

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21 hours ago, peter shah said:

 Bortle at the site is 2-3 so pretty dark.....Those satellite trails are sickening!!

Wow, never seen anything less than Bortle 3 and that was at Olly's place. Best I can normally get is Birtle 4 and have to go to Astro camp for that.

 

carole 

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2 hours ago, Carastro said:

Wow, never seen anything less than Bortle 3 and that was at Olly's place. Best I can normally get is Birtle 4 and have to go to Astro camp for that.

 

carole 

it does depend on the humidity and how much the moisture  scatters the light from the surrounding towns.

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