Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

CMOS short exposure from severe LP zone NGC6946

This topic has been archived. This means that you cannot reply to this topic.
6 replies to this topic

#1 vdb

vdb

    Surveyor 1

  • -----
  • topic starter
  • Posts: 1,618
  • Joined: 08 Dec 2009

Posted 23 May 2017 - 09:53 AM

I'm convinced, after years of imaging with QSI683 and SX814, my new king is the QHY 163M

This image needs another 4 to 5x imaging time, but I could not wait to share first LRGB results of this camera,

so yes there is noise, but at 30sec subs for LRGB and a total of 300 subs I was impatient after first night and processed the set anyway. The processing in itself is a feast, just used 100 bias frames, no dark, no flats. Offset was 60 gain 30

I cropped to take care of vignet, but hey the FOV still is acceptable ...

I live in a red zone, and true dark is almost gone so half of the set was taken in astronomical twilight ...

 

Who could ever imaging a camera at a fraction of the cost, producing such results in a short total amount of time, 2.5h ...

 

 

 

 

 

34002288474_2349311f67_c.jpgNGC6946 by Yves, on Flickr



#2 LoveChina61

LoveChina61

    Surveyor 1

  • *****
  • Posts: 1,763
  • Joined: 19 Jun 2009

Posted 23 May 2017 - 10:44 AM

Awesome!

 

Mike



#3 Aenima

Aenima

    Explorer 1

  • -----
  • Posts: 62
  • Joined: 29 Aug 2012

Posted 23 May 2017 - 11:53 AM

Excellent work, and impressive for the time spent smile.gif

 

 

Can i ask, what about amp glow?  Was there only a small amount due to very short subs? or was it removed by the bias frames? or something else, like removed by DBE or gradient tool?

 

 (i usually use darks to reduce the amp glow, so am curious about what happens when no darks are used)

 

 

Thanks for any info smile.gif

 

 

Congrats on a great shot.


Edited by Aenima, 23 May 2017 - 11:57 AM.


#4 vdb

vdb

    Surveyor 1

  • -----
  • topic starter
  • Posts: 1,618
  • Joined: 08 Dec 2009

Posted 23 May 2017 - 12:53 PM

Just for fun and to see if there was some IFN, which Kees pointed out to me, is not possible as it is interstellar dust ... an extreem stretch of data, I need to get 5x to see if it's real.

Attached Thumbnails

  • NGC6946PS-extreemPS-s.jpg


#5 vdb

vdb

    Surveyor 1

  • -----
  • topic starter
  • Posts: 1,618
  • Joined: 08 Dec 2009

Posted 24 May 2017 - 12:05 AM

@Aenima,

this is a crop so if there would be any amp glow it's not in the image, that said there was no visible amp glow in the stack made of 30 sec subs, I only used bias frames to calibrate.

I did some 5 minute subs for a NB image and it had amp glow, and because it was an NB image it was very noticeable as I could stretch very aggressively, there I used a stack of 50 darks, it took care of the amp glow completely ... so yes this camera has amp glow, but it calibrates out.

(most camera's have some kind of amp glow even my ccd ones, not as severe, that is why you calibrate)

 

 

 

/Yves


Edited by vdb, 24 May 2017 - 12:35 AM.


#6 vdb

vdb

    Surveyor 1

  • -----
  • topic starter
  • Posts: 1,618
  • Joined: 08 Dec 2009

Posted 24 May 2017 - 12:00 PM

Bit more color on the LP, I live between Antwerp and Brussels, Kontich to be exact,

should by an SQM meter to put this in perspective.

 

Nasa even has a webpage on how terrible the situation is ;-)

https://visibleearth...ew.php?id=83599

 

/Yves

 

 

Attached Thumbnails

  • Screen Shot 2017-05-24 at 18.54.46.jpg


#7 Aenima

Aenima

    Explorer 1

  • -----
  • Posts: 62
  • Joined: 29 Aug 2012

Posted 03 June 2017 - 01:07 PM

@Aenima,

this is a crop so if there would be any amp glow it's not in the image, that said there was no visible amp glow in the stack made of 30 sec subs, I only used bias frames to calibrate.

I did some 5 minute subs for a NB image and it had amp glow, and because it was an NB image it was very noticeable as I could stretch very aggressively, there I used a stack of 50 darks, it took care of the amp glow completely ... so yes this camera has amp glow, but it calibrates out.

(most camera's have some kind of amp glow even my ccd ones, not as severe, that is why you calibrate)

 

 

 

/Yves

Thank you :) its good to know the shorter exposures were less affected by Amp glow.

 

I find im liking the 163m more as time goes by. 




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics