Horsehead nebula from a newbie, through Siril

[AstroLearnerWill]

Posting only the third image I've captured and processed after building an astrophotography rig. 

Any thoughts / guidance is appreciated and welcome, you only get better by listening to what other more experienced folk have to say. 

I'm using the updated version of Siril (1.2), and trying the new generalised hyperbolic stretch tool. My peak ended up being left of the 25% mark so I don't think I did that well. 

You can also see a satellite artefact in the image which isn't great. 

Overall I think there is a ton of detail in my images, which I'm pleased with and I'm sure can do better with it, but the contrast isn't great and the sky isn't very 'dark' in the image. I'm bortle 5 and this was taken on the 26th Feb 23. 

Thanks

 

Equipment:

HEQ5 Pro, skywatcher 80ed, 0.85 flattener, modified D600, guidecam, l-enhance filter.

Images:

18 x 9minute subs + biases + flats + only 2 darks.

Processing:

All in Siril 1.2.0. Preprocessing + manual selection of stacking images. 

* Photometric CC, Background extraction, generalised hyperbolic stretch. 

[LuckieEddie]

Nice.

For any given amount of time on a target, I'd suggest taking significantly more exposures, even if they have to be shorter. 10's or even better 100's of subs will let the stacking average out the noise, including satellite trials. For the same reason 10's of darks are recommended.

[AstroLearnerWill]

14 hours ago, LuckieEddie said:

Nice.

For any given amount of time on a target, I'd suggest taking significantly more exposures, even if they have to be shorter. 10's or even better 100's of subs will let the stacking average out the noise, including satellite trials. For the same reason 10's of darks are recommended.

Gotcha. I was thinking I might take some more lights when I get a chance in the upcoming weeks, and also some darks (though the jury seems to be out regarding if they're useful for DSLRs with the temp fluctuations), and then compare the images. 

On a separate note, I would love to learn more about post processing, someone with a lot of experience should do an online course on it, I would certainly pay for that! For now though I guess we have tutorials and youtube videos. But it's a tricky one to know where to start for beginners.  

[wongataa]

Nice detail on the Horsehead.  The Flame Nebula looks too red though.

As you are using a DSLR using no dark frames could well be better. Dark frames need to be temperature matched and you can't control temperature on a DSLR.  Also, unless your camera has fixed pattern noise or amp glow then you don't really need them.  If you do use them you need a lot more.  Experiment with and without them to see what works best.

[ollypenrice]

I agree with earlier posts. 9 mins is a long time for a DSLR. I'd try more and shorter.

2 darks will add noise, not reduce it, and on DSLRs you'd probably do better to use a master bias as a dark anyway.

On processing, I'd be looking at:

-The flame being too red and not yellow enough.

The blues being too green.

The bright stars being colourless and surrounded by colourless circles introduced in processing. I don't know how they got there, though. Does the software attempt to mask the bright signal, or have you masked the bright stars in some way? Whatever the answer, it has not worked in the image's favour.

Personally, I never use any ready made stretches. The stretch is the absolute number one post processing priority and it seems to me that learning the ropes of a stretch tailored to just the one image in question is the key thing.

In this part of the sky there is no background at all. Your framing is full of nebulosity and your black point is good.

Olly

Edit. It really is useful to have Photoshop to do cosmetic repairs such as your sat trails, though AstroArt has a 'Remove Line' feature so maybe other astro packages also have it. I don't know.

Edited February 28, 2023 by ollypenrice
Stated

[AstroLearnerWill]

22 hours ago, ollypenrice said:

that learning the ropes of a stretch tailored to just the one image in question is the key thing

Agree - I do struggle with understanding how and what this is, and it ends up being a bit of a lottery how it turns out.
I've got the basics of what a histogram is but need to find some tutorials / videos on proper stretching / transformation / that side of things

[ollypenrice]

6 minutes ago, AstroLearnerWill said:

Agree - I do struggle with understanding how and what this is, and it ends up being a bit of a lottery how it turns out.
I've got the basics of what a histogram is but need to find some tutorials / videos on proper stretching / transformation / that side of things

Beware of buffoons on U-tube! It is full of people heaving this way and that on an assortment of sliders till they 'get something they like.'   Look out for Adam Block and Warren Keller, who can be relied upon.

Olly

 

[AstroLearnerWill]

5 hours ago, ollypenrice said:

Beware of buffoons on U-tube! It is full of people heaving this way and that on an assortment of sliders till they 'get something they like.'   Look out for Adam Block and Warren Keller, who can be relied upon.

Olly

 

Thanks for the recommendations!