Jump to content

My M13...


Recommended Posts

120 sec x 180 subs.  Thinking I could probably take this down to 60 second subs if I try it again and get those stars a little tighter.  Probably just a fact of life with this particular focal length, even with the reducer.  Processed in Siril and GIMP.  Seeing was "ok" but not great, and of course, there was the full moon and the streetlamp on the corner 🤬.  Not a patch on @mightymonoped or @AstronomyUkraine 's versions, for sure but I am reasonably pleased!

 

Celestron 8SE > .62 reducer > LP filter > ASI294MC Pro.  Guiding with a 290MM thru 60mm svbony and actually staying below 1" most of the time other than when recovering from a dither or a stray gust of wind.

 

Thanks for the continual inspiration, guys!

 

M13_Siril.jpg

  • Like 9
Link to comment
Share on other sites

Don’t knock it Adam, that’s a very worthy image plentygoing on in the distance and a great natural feel to the Glob. Well done

  • Thanks 1
Link to comment
Share on other sites

Here's another stab at it to try to tone down the centre and shrink the stars.   Sooner or later I'm going to have to start spending money on software to make this easier on myself lol.

 

 

M13 attempt 2 GIMP.jpg

Link to comment
Share on other sites

I know where you’re coming from, been there and done that. I actually prefer the first image even though the core is over-blown slightly. I’ve not done a glob in years, certainly not since acquiring better skills with PI. Perhaps I should repro some old data and see what happens. 

  • Like 1
Link to comment
Share on other sites

Thanks!  There is definitely more of a sense of - depth?  motion?  on the first one that isn't present in the second one.  So far my tools for DSO have been DSS or Siril then GIMP.  I thought about Photoshop but I just don't care for the subscription model of pricing.  PI seems to be the standard for the astro stuff.  Also pricey, but I suppose I'm in it now.

 

Next time I think I might cut the exposure time down even more and see what happens.  I know I'll probably never get perfect little pinprick stars with an 8" SCT, but there is still work to be done.  I also need a better way of discarding subs than manually flipping through 200 of them... 🤯

 

I would love to see one of your old ones, Keith!

  • Like 1
Link to comment
Share on other sites

In my mind, PI is the best and most useful 'all in one' tool. I'm sure others will disagree, but with the range of scripts and plug-ins that are available, even if they have to be purchased like RC Astro Xterminators, they represent excellent value and a lifetime of updates and support.

Anyway, here's my M3 after a quick re-process. It's far from the best....if the focus was tighter, if the subs were better etc etc. It's grainy and the core is blown, but I don't care! It's mine lol.

Data captured in 2020 I think.

 

M3.jpg

  • Like 3
Link to comment
Share on other sites

On 5/5/2023 at 1:54 PM, Adam Y said:

I also need a better way of discarding subs than manually flipping through 200 of them

PixInsight has a module called Blink which does exactly that. Just load a stack of image files in, click auto stretch all and click play. It displays each image for a short while and then goes onto the next one. You then see a movie of the frames and are able to stop it, manually go back and forth to see the dodgy frame, mark it/them and then delete it/them. In reality it moves the files to a place you define (I have a folder called Bin).

 

There are other modules that will mathematically work out bad frames but Blink is where I start. There is an option to get a trial 45 day PI license to try it out https://pixinsight.com/trial/index.html

 

I use PI entirely for processing astro now having resigned Photoshop to use on terrestrial photographs.

  • Like 2
Link to comment
Share on other sites

11 hours ago, RaDec said:

Anyway, here's my M3 after a quick re-process. It's far from the best....if the focus was tighter, if the subs were better etc etc. It's grainy and the core is blown, but I don't care! It's mine lol.

Try using HDRMultiScaleTransform on your core. A setting of 6 or 7 will greatly reduce the blown out portion of the cluster.

  • Thanks 1
Link to comment
Share on other sites

On 5/7/2023 at 3:18 AM, TerryMcK said:

PixInsight has a module called Blink which does exactly that. Just load a stack of image files in, click auto stretch all and click play. It displays each image for a short while and then goes onto the next one. You then see a movie of the frames and are able to stop it, manually go back and forth to see the dodgy frame, mark it/them and then delete it/them. In reality it moves the files to a place you define (I have a folder called Bin).

 

There are other modules that will mathematically work out bad frames but Blink is where I start. There is an option to get a trial 45 day PI license to try it out https://pixinsight.com/trial/index.html

 

I use PI entirely for processing astro now having resigned Photoshop to use on terrestrial photographs.

I am seriously considering PI, especially if I can skip the final processing stuff I do in GIMP (which saves me from a monthly PS bill).  

 

Meanwhile, I think I have figured out how to do something similar in Siril:

  1.  After creating the preprocessed and background-extracted Lights sequence with all the .fit files (early/midway in the processing workflow), open the bkg_pp_lights sequence and go to Image Processing > Histogram transformation.  (If you don't do per-sub background extraction, just open the pp_lights.). Apply an autostretch, then click Apply to Sequence.  This will create a new sequence of lights with a stretch_ prefix.    This will eventually be discarded.
  2. Load the new sequence in the Sequence tab, in the Export section, choose a base name ("M13_blink" for example) then output type as SER.  Export sequence.  Now you can delete the autostretched lights sequence file which is just taking up space.
  3. Open the SER file with the PIPP SER viewer and set the frame rate to 1/sec (or whatever works).  Note that it starts numbering with 0, so if you want to delete Frame 17, that may be sub_16.fit.
  4.  Then you can either delete the files and recreate the lights sequence, or proceed to Registration and then discard from there.  

Anyway, might fill the void until I can justify the spend on PI.  

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...