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

M57 - small , nice but difficult...

  • Please log in to reply
15 replies to this topic

#1 F.Meiresonne

F.Meiresonne

    Cosmos

  • *****
  • topic starter
  • Posts: 7,683
  • Joined: 22 Dec 2003
  • Loc: Eeklo,Belgium

Posted 12 June 2021 - 11:24 AM

I tried to image M57 in my 130 mm F/7.

 

Object is too small.

I had issues with my laptop that fore some reason did not want to launch teamviewer and APT refused to connec to the DSLR. When i had this all sorted out it was allready past 0:30am ....

Eventually got 2:25 hr of integration time. 145 subs of 60 sec, 53 flats and bias.

 

Got to bed around 03:40 am....can't stand it....zombie state next day.....

 

Maybe not the best target for my telescope.

But the outer red HA is visible and so  is the faint IC 1296 spiral galaxie 

 

https://www.cloudyni...911_1535196.png

Attached Thumbnails

  • M57_4.jpg

Edited by F.Meiresonne, 12 June 2021 - 12:16 PM.

  • zjc26138, mtc, Magellanico and 21 others like this

#2 bobzeq25

bobzeq25

    ISS

  • *****
  • Posts: 25,610
  • Joined: 27 Oct 2014

Posted 12 June 2021 - 11:42 AM

Very nice.  But, in the words of Crocodile Dundee, that's not a small image of M57.  This is a small image of M57.    Click on "technical card" for an explanation.

 

https://www.astrobin.../full/262902/B/


  • Jay6879 and galacticinsomnia like this

#3 F.Meiresonne

F.Meiresonne

    Cosmos

  • *****
  • topic starter
  • Posts: 7,683
  • Joined: 22 Dec 2003
  • Loc: Eeklo,Belgium

Posted 12 June 2021 - 12:19 PM

Very nice.  But, in the words of Crocodile Dundee, that's not a small image of M57.  This is a small image of M57.    Click on "technical card" for an explanation.

 

https://www.astrobin.../full/262902/B/

hah, yes Bob...

 

I cropped the jpg quite a bit but the link to the png resembles yours....

 

It is just tooooo small...still nice, why not...

 

Besides it was a second test for the 130 mm...looking good...no blue halos around any star..

 

Wonder if i should try to get some  extra Ha with the mono....better try it....again..why not...



#4 hobbyknipser

hobbyknipser

    Messenger

  • -----
  • Posts: 414
  • Joined: 23 Jul 2019
  • Loc: Germany Orange Zone

Posted 12 June 2021 - 01:32 PM

Hi, Freddy,

 

very nice result! waytogo.gif

 

For me it seems: the background is a little bit too dark and M57 itself a little bit overexposured (two bright sides of M57)(you used too high ISO or the 60 sec were too long or too much stretched by you). What do you think?

 

cheers

Andreas



#5 F.Meiresonne

F.Meiresonne

    Cosmos

  • *****
  • topic starter
  • Posts: 7,683
  • Joined: 22 Dec 2003
  • Loc: Eeklo,Belgium

Posted 12 June 2021 - 02:09 PM

I used iso 400, It is strange but i had this on M97 some time ago too. Picture looks a bit better on my quad hd monitor but indeed the 2 white spots troubled.

me..

 

I don't really know what is causing this...maybe i just stretched a bit too much...

 

Well, surely  not the best image ever, but it was fun, despite the hassle ...


Edited by F.Meiresonne, 12 June 2021 - 02:19 PM.


#6 bobzeq25

bobzeq25

    ISS

  • *****
  • Posts: 25,610
  • Joined: 27 Oct 2014

Posted 12 June 2021 - 02:30 PM

It's hard to capture the outer halo without clipping the bright parts.  There are advanced techniques, but I think this is more than acceptable.  The outer halo is tough.


  • F.Meiresonne and galacticinsomnia like this

#7 galacticinsomnia

galacticinsomnia

    Apollo

  • *****
  • Posts: 1,475
  • Joined: 14 Aug 2020
  • Loc: Pacific Northwest - Oregon

Posted 12 June 2021 - 03:30 PM

I like it. Good Suff. !!

Clear Skies !!



#8 Aquat0ne

Aquat0ne

    Vostok 1

  • -----
  • Posts: 191
  • Joined: 23 Sep 2019

Posted 12 June 2021 - 08:01 PM

As above. Looks great.

#9 F.Meiresonne

F.Meiresonne

    Cosmos

  • *****
  • topic starter
  • Posts: 7,683
  • Joined: 22 Dec 2003
  • Loc: Eeklo,Belgium

Posted 13 June 2021 - 03:40 AM

Thanks,

 

Just have still to find out what caused this white spots...maybe a good question for Ivo..grin.gif



#10 F.Meiresonne

F.Meiresonne

    Cosmos

  • *****
  • topic starter
  • Posts: 7,683
  • Joined: 22 Dec 2003
  • Loc: Eeklo,Belgium

Posted 13 June 2021 - 11:00 AM

Anothre atttempt, slightly better imo, but i cannot get rid of the white spots in the nebulae

 

 

link to the fts stack should one willing to try it

 

https://www.dropbox....sd/M57.fts?dl=0

Attached Thumbnails

  • M57_2.jpg

  • aacc66 likes this

#11 F.Meiresonne

F.Meiresonne

    Cosmos

  • *****
  • topic starter
  • Posts: 7,683
  • Joined: 22 Dec 2003
  • Loc: Eeklo,Belgium

Posted 13 June 2021 - 11:00 AM

Heavily cropped

 

Attached Thumbnails

  • CroppedM57.jpg


#12 chanrobi

chanrobi

    Viking 1

  • -----
  • Posts: 902
  • Joined: 02 Sep 2019

Posted 13 June 2021 - 12:27 PM

Very nice.  But, in the words of Crocodile Dundee, that's not a small image of M57.  This is a small image of M57.    Click on "technical card" for an explanation.

 

https://www.astrobin.../full/262902/B/

That's actually cool, you get to see the context and what it really looks like from most scopes.

 

And just how small this object is in the sky.


  • bobzeq25 likes this

#13 bobzeq25

bobzeq25

    ISS

  • *****
  • Posts: 25,610
  • Joined: 27 Oct 2014

Posted 13 June 2021 - 05:24 PM

Heavily cropped

 Just a possibility.  I think perhaps what you're seeing is data that is clipped high (or saturated).  It's blue nebula, but once color channels hit 255.255.255. you lose all color.  The dot effect is because that's the area that's clipped high, nearby is still blue.  That could be real, could be noise.

 

If that's the case, the answer is to lower subexposure (time, gain, or both) to avoid clipping.  It's possible that processing could help.

 

That could be completely wrong, also.

 

When we're trying to help you diagnose issues, the more data we have, the better.  All the equipment, all the software, all the acquisition details.  Something you think is unimportant - may not be.


Edited by bobzeq25, 13 June 2021 - 05:30 PM.


#14 Mike in Rancho

Mike in Rancho

    Apollo

  • -----
  • Posts: 1,391
  • Joined: 15 Oct 2020
  • Loc: Alta Loma, CA

Posted 13 June 2021 - 11:27 PM

I gave it a try Freddy.  Everything seems surprisingly bright for only 60 second subs, which has me confused.

 

Indeed the object is small.  I was just running into the same sort of thing with my M104.  Only so much can be done with my data using a big crop - especially since that limits binning, and I'm probably better off with a wider-field crop.  Same might be true here.

 

It doesn't take much of a stretch at all for things to start blowing out full white, including that ring of M57 plus most of your stars.  Not just that one really bright star, but lots of them.  Weird.

 

Unless this was an unusually high ISO, I'm befuddled.  Might want to treat this as a multi exposure target, like M42 and the Triangulum?  Or try to blend various stretches here in layers.  The stars are easy enough for the background, there's good color and a core blur will rescue them from max saturation.  I tried different HDR settings under Reveal Core - lowering the detail size way down will start taming down that fat white ring, even to where it is quite thin as is seen in some M57 internet images, but some of the surrounding detail gets weird at the same time.

 

So, I don't have any good version of this as yet..



#15 F.Meiresonne

F.Meiresonne

    Cosmos

  • *****
  • topic starter
  • Posts: 7,683
  • Joined: 22 Dec 2003
  • Loc: Eeklo,Belgium

Posted 14 June 2021 - 12:43 AM

So maybe overexposed anyhow...well off course it is a bright object....puzzling.

 

@Mike : i always use iso 400 on the 800D Canon. Nothing else...seems according to the Elf the best setting for this camera

 

Full specs : 130 mm F/7 APO triplet - Canon 800D unmodded - 1 minutes subs  145x, 53 flats, about 50 bias.

 

Maybe next time i just cut the expose time in half and see what i will get. The scope is new, this is only my second session, so no experience.

Maybe i underestimated the light gathering power ....


Edited by F.Meiresonne, 14 June 2021 - 12:52 AM.

  • Mike in Rancho likes this

#16 Mike in Rancho

Mike in Rancho

    Apollo

  • -----
  • Posts: 1,391
  • Joined: 15 Oct 2020
  • Loc: Alta Loma, CA

Posted 15 June 2021 - 02:11 AM

So maybe overexposed anyhow...well off course it is a bright object....puzzling.

 

@Mike : i always use iso 400 on the 800D Canon. Nothing else...seems according to the Elf the best setting for this camera

 

Full specs : 130 mm F/7 APO triplet - Canon 800D unmodded - 1 minutes subs  145x, 53 flats, about 50 bias.

 

Maybe next time i just cut the expose time in half and see what i will get. The scope is new, this is only my second session, so no experience.

Maybe i underestimated the light gathering power ....

Could be right Freddy.  For my last few targets, I've actually been at ISO200 for 120 seconds.  I used to use 400 more often.  Maybe I've had some clearer, darker skies, or I just realized 200 was good.  If the cameras are still using the same standards, should be closely equivalent to your 400 for 60 seconds.

 

But I'm also at 100mm and F/9, so wimpier than your 130 and F/7.  And I think aperture rises in importance when we're just talking stars?


Edited by Mike in Rancho, 15 June 2021 - 02:12 AM.



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