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

Some nebula pictures from last weekend

  • Please log in to reply
31 replies to this topic

#1 MikeGS

MikeGS

    Sputnik

  • -----
  • topic starter
  • Posts: 29
  • Joined: 14 Sep 2018
  • Loc: Terrassa (Barcelona)

Posted 08 July 2019 - 07:06 AM

Hi all,

just wanted to share my work from last weekend.

Equipment used: Skywatcher 300p Flextube Goto Dobson, asi294, baader uhc filter.

 

Captures: all of them taken with Sharpcap, 3s subframes at 570 gain (60s total time), with darks. No post procesing, just played with histogram.

 

Comments wellcome.

 

 

Attached Thumbnails

  • Dumbell.jpg

  • highfnum, S1mas, saguaro and 8 others like this

#2 MikeGS

MikeGS

    Sputnik

  • -----
  • topic starter
  • Posts: 29
  • Joined: 14 Sep 2018
  • Loc: Terrassa (Barcelona)

Posted 08 July 2019 - 07:08 AM

M16

Attached Thumbnails

  • M16 aguila.jpg

  • Starman27, roelb, mikenoname and 3 others like this

#3 MikeGS

MikeGS

    Sputnik

  • -----
  • topic starter
  • Posts: 29
  • Joined: 14 Sep 2018
  • Loc: Terrassa (Barcelona)

Posted 08 July 2019 - 07:09 AM

M 8

Attached Thumbnails

  • Lagoon.jpg

  • S1mas, happylimpet, roelb and 4 others like this

#4 MikeGS

MikeGS

    Sputnik

  • -----
  • topic starter
  • Posts: 29
  • Joined: 14 Sep 2018
  • Loc: Terrassa (Barcelona)

Posted 08 July 2019 - 07:09 AM

M 17

Attached Thumbnails

  • Omega.jpg

  • S1mas, saguaro, happylimpet and 7 others like this

#5 MikeGS

MikeGS

    Sputnik

  • -----
  • topic starter
  • Posts: 29
  • Joined: 14 Sep 2018
  • Loc: Terrassa (Barcelona)

Posted 08 July 2019 - 07:10 AM

M 20

Attached Thumbnails

  • Trifid.jpg

  • S1mas, happylimpet, roelb and 5 others like this

#6 MikeGS

MikeGS

    Sputnik

  • -----
  • topic starter
  • Posts: 29
  • Joined: 14 Sep 2018
  • Loc: Terrassa (Barcelona)

Posted 08 July 2019 - 07:11 AM

NGC 6888

Attached Thumbnails

  • NGC 6888.jpg

  • happylimpet, roelb, mikenoname and 2 others like this

#7 Hubert

Hubert

    Ranger 4

  • -----
  • Posts: 376
  • Joined: 26 Sep 2006
  • Loc: Belgium

Posted 08 July 2019 - 08:31 AM

Very nice done waytogo.gif



#8 happylimpet

happylimpet

    Aurora

  • *****
  • Posts: 4,758
  • Joined: 29 Sep 2013
  • Loc: Southampton, UK

Posted 08 July 2019 - 08:35 AM

Lovely images.

 

Recently I've enjoyed the images on the EAA forum more than the 'CCD/CMOS' ones etc, as they actually look like the objects in question and havent had the ###### processed out of them to the point of being unrecognizable.


  • bdyer22 and descott12 like this

#9 descott12

descott12

    Vendor - Solar Live View

  • *****
  • Vendors
  • Posts: 2,143
  • Joined: 28 Sep 2018
  • Loc: Charlotte, NC

Posted 08 July 2019 - 09:25 AM

Hi all,

just wanted to share my work from last weekend.

Equipment used: Skywatcher 300p Flextube Goto Dobson, asi294, baader uhc filter.

 

Captures: all of them taken with Sharpcap, 3s subframes at 570 gain (60s total time), with darks. No post procesing, just played with histogram.

 

Comments wellcome.

Great shots Mike, I captured an almost identical set in the last few days.

Question: 570 gain?   I have the same camera and think the gain maxes out at something like 515 or 550 and I would never use anything higher than about 270 or 300.  Was that a typo? 

 

Attached is my Eagle Nebula - Evo 8 + Hyperstar + 294 MC + IDAS LPS P2.  5x10 seconds, gain 250

Attached Thumbnails

  • 12.png

Edited by descott12, 08 July 2019 - 09:27 AM.

  • Hubert and roelb like this

#10 Gyroman

Gyroman

    Sputnik

  • *****
  • Posts: 29
  • Joined: 31 Mar 2019
  • Loc: Spokane, WA

Posted 08 July 2019 - 12:24 PM

Lovely images.

Recently I've enjoyed the images on the EAA forum more than the 'CCD/CMOS' ones etc, as they actually look like the objects in question and havent had the ###### processed out of them to the point of being unrecognizable.


I would agree with that. It might be my own incompetence with photoshop but I'm a big fan of EAA as of now.

The ability to see significantly more than fuzzies in my Bortle 5 backyard yet not deal with the complexity (and expense) of true high quality Astrophotography works for me.
  • Roger Corbett and lids344 like this

#11 davidparks

davidparks

    Viking 1

  • *****
  • Posts: 660
  • Joined: 20 Jul 2017
  • Loc: Battle Creek, MI - USA

Posted 08 July 2019 - 01:37 PM

The gain for 294 will go to 570 in Sharpcap.  Once of the great things about the 294 is it's HCG Mode that kicks in at 120 (and higher) keeping the read noise fairly flat.  Higher gain will lose some dynamic range, but there is no reason you can't use higher gains... and stacking and dithering go a long way to improve the SNR.

 

Great results MikeGS!  Especially like your M27!



#12 descott12

descott12

    Vendor - Solar Live View

  • *****
  • Vendors
  • Posts: 2,143
  • Joined: 28 Sep 2018
  • Loc: Charlotte, NC

Posted 08 July 2019 - 01:41 PM

The gain for 294 will go to 570 in Sharpcap.  Once of the great things about the 294 is it's HCG Mode that kicks in at 120 (and higher) keeping the read noise fairly flat.  Higher gain will lose some dynamic range, but there is no reason you can't use higher gains... and stacking and dithering go a long way to improve the SNR.

 

Great results MikeGS!  Especially like your M27!

I wasn't sure how high it went.Yes, I always keep it above 120 but things get real noisy for me above about 350 or so (and that is with the cooler on).



#13 MikeGS

MikeGS

    Sputnik

  • -----
  • topic starter
  • Posts: 29
  • Joined: 14 Sep 2018
  • Loc: Terrassa (Barcelona)

Posted 09 July 2019 - 01:51 AM

Hi guys, thanks for your comments.

 

Yes, I know 570 gain sounds like too much. But the asi294 seems to handle it fairly well. I tend to use the maximum gain I can in order to shorten the subframes time and thus the total exposure time. Going beyond the 60s will usually produce noticebale field rotation, so that's why I push the camera to its limits.

 

Keep in mind I use darks to minimize the noise and hot pixels. The baader UHC filter also requires high gain values, otherwise the result is too dark.

 

Mike.


  • davidparks likes this

#14 Hubert

Hubert

    Ranger 4

  • -----
  • Posts: 376
  • Joined: 26 Sep 2006
  • Loc: Belgium

Posted 09 July 2019 - 02:31 AM

Hi Mike, when do you make these darks? Every time Before you start your image session or do you use old ones?

#15 MikeGS

MikeGS

    Sputnik

  • -----
  • topic starter
  • Posts: 29
  • Joined: 14 Sep 2018
  • Loc: Terrassa (Barcelona)

Posted 09 July 2019 - 02:53 AM

Hi Hubert!

Darks can't be recycled from session to session (well you can, but you shouldn't). Conditions are different each night: temperature, humidity, pollution, seeing, etc..

 

Taking darks is really really simple, especially for EAA where you don't need long exposure times. For me it's just 1 minute (same time as the total exposure I want for my captures).

 

I usually take the darks after 30 minutes or even more with the tube out and the camera connected, in order to stabilize both the mirror and the camera to the outside conditions. After that time, I cover the scope for 1 minute and take the darks. That easy :-)


Edited by MikeGS, 09 July 2019 - 02:57 AM.


#16 Hubert

Hubert

    Ranger 4

  • -----
  • Posts: 376
  • Joined: 26 Sep 2006
  • Loc: Belgium

Posted 09 July 2019 - 03:07 AM

And you do this all in Sharpcap?

#17 MikeGS

MikeGS

    Sputnik

  • -----
  • topic starter
  • Posts: 29
  • Joined: 14 Sep 2018
  • Loc: Terrassa (Barcelona)

Posted 09 July 2019 - 03:15 AM

Yes, everything from Sharcap, except going out to cover the scope lol.gif  

 

However, I think darks option is only available in the pro versión, which is about 14$/year (the one I paid for).


Edited by MikeGS, 09 July 2019 - 03:16 AM.


#18 Hubert

Hubert

    Ranger 4

  • -----
  • Posts: 376
  • Joined: 26 Sep 2006
  • Loc: Belgium

Posted 09 July 2019 - 04:30 AM

I also have the pro version but never tried the darks option.

#19 MikeGS

MikeGS

    Sputnik

  • -----
  • topic starter
  • Posts: 29
  • Joined: 14 Sep 2018
  • Loc: Terrassa (Barcelona)

Posted 09 July 2019 - 06:57 AM

Then I recommend you using darks, since you have the pro versión. It's really easy to do and will help you improving your captures quality.

 

I can notice a lot the improvement because: 1) I use high gain values 2) I got the uncooled asi294 versión

 

Just remember taking the darks with the same exact values (gain, exp time) as you are going to capture your images.



#20 Hubert

Hubert

    Ranger 4

  • -----
  • Posts: 376
  • Joined: 26 Sep 2006
  • Loc: Belgium

Posted 09 July 2019 - 07:28 AM

I also have the Asi 294MC, not cooled. I use Sharpcap for solar and moon pictures with my Asi 290 mono. I'm intended to do EAA with the 294 in the near future. Thanks for the info about the darks.

#21 descott12

descott12

    Vendor - Solar Live View

  • *****
  • Vendors
  • Posts: 2,143
  • Joined: 28 Sep 2018
  • Loc: Charlotte, NC

Posted 09 July 2019 - 09:00 AM

Hi Mike, when do you make these darks? Every time Before you start your image session or do you use old ones?

Hmmm, I thought you could create a library of darks? That is one  advantage of a cooled camera in that you can set the temp, create darks for the various settings you intend to use and save them for later use.

But maybe I have that wrong....I know flats generally need to be recreated each session but I thought darks were different.



#22 mikenoname

mikenoname

    Viking 1

  • *****
  • Posts: 680
  • Joined: 29 Jan 2015
  • Loc: Death Valley Region (Bortle 2 - SQM 21.9+)

Posted 09 July 2019 - 10:17 AM

Hmmm, I thought you could create a library of darks?

 

Correct. MikeGS's practice of taking darks for every session is overkill. As long as your camera settings (gain, exposure, etc.) are the same and the temperature is within a couple of degrees of a dark you already have in your library, it is usually fine to use.

 

I have a library of darks every 5 degrees and use them all the time. The only time I make new ones is when I hit a new temperature range or change a significant camera setting.


  • Lorenz0x7BC likes this

#23 MikeGS

MikeGS

    Sputnik

  • -----
  • topic starter
  • Posts: 29
  • Joined: 14 Sep 2018
  • Loc: Terrassa (Barcelona)

Posted 09 July 2019 - 11:35 AM

Correct. MikeGS's practice of taking darks for every session is overkill. As long as your camera settings (gain, exposure, etc.) are the same and the temperature is within a couple of degrees of a dark you already have in your library, it is usually fine to use.

I have a library of darks every 5 degrees and use them all the time. The only time I make new ones is when I hit a new temperature range or change a significant camera setting.


That makes sense. I thought darks were more “sensitive” so you needed to create them every session. It’s good advice to have a dark library within a range of settings and use the most convinient set for the current session.
Will do that way from now on.
Thanks!!
  • mikenoname likes this

#24 Hubert

Hubert

    Ranger 4

  • -----
  • Posts: 376
  • Joined: 26 Sep 2006
  • Loc: Belgium

Posted 09 July 2019 - 12:37 PM

There are different opinions about the darks. Some say that you have to make them every session when the camera is not cooled. That you only can make a library when the camera is cooled.

#25 mikenoname

mikenoname

    Viking 1

  • *****
  • Posts: 680
  • Joined: 29 Jan 2015
  • Loc: Death Valley Region (Bortle 2 - SQM 21.9+)

Posted 09 July 2019 - 01:05 PM

That you only can make a library when the camera is cooled.

 

That is certainly not true.




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