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4am Orion, I think this is my first real success

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#1 awong101

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Posted 22 September 2020 - 02:08 AM

I've been looking forward to Orion rising here in the Northern Hemisphere, and the rest of the Winter targets. Even if I had to wait until ~4am, it did not disappoint! I was able to have a nice session until the sun came out.

 

I think I can finally start making some progress now that I am no longer dealing with a defective filter. 

 

Here is the un-processed stacked image, feel free to take a look at it and provide some feedback please. Do you think I am out of focus? There is still a lot for me to learn and I believe this is my 4th image. (All of the previous sessions were throwaway data, bad filter):

 

https://drive.google...iew?usp=sharing

 

WO Spacecat 51

Sky-Watcher Star Adventurer Pro

Camera: Canon 60D Baader HA Mod

Filter: IDAS LPS D1

ISO: 800

Exposure: 60 seconds

Subs: 107

Total integration time: 1 hour 37 minutes

# Darks: 40

# Flats: 40

# Bias: 40

 

Here is my attempt at post processing with Photoshop:

- Levels

- Curves

No saturation or vibrance adjustment. I felt that it was unnecessary and gave off a false color. 

- Additional actions from the Astrophotography Tools Actions Set

 

It's little small victory like this that keeps me intrigued about this new hobby. The learning curve is steep, and there's a never ending flow of knowledge out there. But at the same time, the struggles and those crisis moments are what keep me motivated. Critique welcomed! smile.gif

Attached Thumbnails

  • Orion-attempt-1---completed LG.jpg

Edited by awong101, 22 September 2020 - 02:45 AM.

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#2 DubbelDerp

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Posted 22 September 2020 - 08:36 AM

That's a good start, and a nice improvement with the replacement filter! My initial impression is that the focus is a bit soft... what are you doing to hit focus? Also, I think you might be hiding some of the dimmer details by having such a flat background. Don't be afraid to show a bit of noise in the background to bring out more of the wispy details.

 

M42 is a really hard target. 60 seconds is a good starting point, but you might want to shoot it again with much shorter exposures, and blend the two images through luminance masks to recover some of the details in the core. But the colors are great in the nebula - good choice not to increase the saturation.

 

I'm going to disagree again about your first images being throw-away. Your Lagoon nebula with the 135mm lens is a keeper. If you want, I can remove the color gradient in APP and send it back to you to process as you see fit. 


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#3 awong101

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Posted 22 September 2020 - 10:39 AM

That's a good start, and a nice improvement with the replacement filter! My initial impression is that the focus is a bit soft... what are you doing to hit focus? Also, I think you might be hiding some of the dimmer details by having such a flat background. Don't be afraid to show a bit of noise in the background to bring out more of the wispy details.

 

M42 is a really hard target. 60 seconds is a good starting point, but you might want to shoot it again with much shorter exposures, and blend the two images through luminance masks to recover some of the details in the core. But the colors are great in the nebula - good choice not to increase the saturation.

 

I'm going to disagree again about your first images being throw-away. Your Lagoon nebula with the 135mm lens is a keeper. If you want, I can remove the color gradient in APP and send it back to you to process as you see fit. 

I'll take your word for it on the Lagoon session, and let me take one last crack at processing it. We can may do a comparison now that I know a little more about post processing. :)

 

I am using the bahtnov mask to achieve focus at the beginning of the night. HOWEVER, I agree that the focus looks "soft" and that I never once re-focused when I moved over to Orion. It would have been 6+ hours since I first focused it. What leads to changes in focus?

 

Ok, I will try a shorter exposure next time and see how much detail of the core I can recover, thank you!



#4 DubbelDerp

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Posted 22 September 2020 - 11:41 AM

Temperature change could shift focus, but it could be as simple as the focus getting bumped when you changed targets. It doesn't take much. You could probably get away with taking a shot with the mask in place once you're on target, just to be sure that the focus is still sharp. A 5-second photo at high ISO should show a good diffraction pattern.

 

Here's a quick run-through of your stack above with Astro Pixel Processor and GIMP. You got quite a bit of the nebula, and the surrounding dust is starting to show. More exposure time (or darker skies) would help this come through.

 

Annotation 2020-09-22 122101.jpg

 

APP:

Crop

Gradient/light pollution removal

Moderate stretch to where the saturation of the core was minimized

 

GIMP:

Multiple iterations of curves to bring out some contrast between portions of the inner nebula

Multiple iterations of curves to bring out some contrast between the outer portions of the nebula

Slight increase in saturation

Decompose into LAB channels, gaussian blur of 5 pixels applied to A and B channel (this helps reduce chrominance noise)

Recompose into color

A few more iterations of curves to darken the background slightly with keeping brightness of outer nebula unchanged

 

I left the background pretty bright, just to show some of the dust starting to appear. I'm sure others would be able to do much better than me!

 


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#5 awong101

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Posted 22 September 2020 - 11:51 AM

Wow, that looks great man. I guess I could stretch it some more... Let me play around with it again.

 

I'm just glad I am capturing decent data (finally).

 

As for the focus, I "locked" on the Spacecat and I got the spikes, every lined up in the beginning of the night. Maybe I didn't lock it tight enough. I will need to be more careful.

 

Or, just focus again since there are bright enough stars nearby Orion, haha.


Edited by awong101, 22 September 2020 - 12:02 PM.

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#6 ChristopherBeere

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Posted 22 September 2020 - 11:59 AM

Watching it roll at 4 am...thats proper astronomy mate.

 

Be patient, good results take time.. An excellent start.


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#7 Craig H

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Posted 22 September 2020 - 12:11 PM

I'm not sure about how solid the Spacecat focuser is but maybe consider not being *too* aggressive locking focus, the very act of doing so could shift your focus slightly.  I like to lock my focuser down so that there is resistance to movement but not 'locked'.  But that depends on your equipment, you'll get a feel for it.

 

Also, temperature does affect focus more than you might think.  Metal/plastic will expand/contract with temperature changes over the night, and fractions of a millimeter change is enough to ruin that crisp look you spent lots of effort in gaining.  If it's early in the night when you start I'd suggest you check your subexposures at least one every half-hour to make sure focus hasn't gotten soft on you.  Later in the night hourly checks should be enough.

 

Clear skies!

Craig.


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#8 awong101

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Posted 22 September 2020 - 12:27 PM

Watching it roll at 4 am...thats proper astronomy mate.

 

Be patient, good results take time.. An excellent start.

There's more to the story, haha I thought I could just take my darks in the early morning hours after the sun came out, because the temperature would still be nearly identical.

 

No deal, the sun out beaming down on the camera absolutely ruined my darks.

 

So I had to wait until the following night, wait until the temperature matched the previous session, and do my darks. (I had a thermometer out with me)

 

Thank you for the encouragement!


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#9 awong101

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Posted 22 September 2020 - 12:30 PM

I'm not sure about how solid the Spacecat focuser is but maybe consider not being *too* aggressive locking focus, the very act of doing so could shift your focus slightly.  I like to lock my focuser down so that there is resistance to movement but not 'locked'.  But that depends on your equipment, you'll get a feel for it.

 

Also, temperature does affect focus more than you might think.  Metal/plastic will expand/contract with temperature changes over the night, and fractions of a millimeter change is enough to ruin that crisp look you spent lots of effort in gaining.  If it's early in the night when you start I'd suggest you check your subexposures at least one every half-hour to make sure focus hasn't gotten soft on you.  Later in the night hourly checks should be enough.

 

Clear skies!

Craig.

Overall, I think the Spacecat is solidly built. But you are right, no need for me to aggressively lock in the focus. I think it's wise to just refocus again especially when there are close-enough nearby stars to use.

 

Thank you for the advice on the temperature, it makes sense. I will be checking my focus more often.




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