Free Mac Photo Stacking Software
Astrophotography is closer to science than art, and there is no such thing as “getting it right in camera.” This means you cannot simply point the camera at the sky and snap away.
Mac OS Windows. If you have a low download speed, please run the commands below and send us the result via the contact form. Windows (CMD): tracert heliconsoft.com ping -n 30 -l 1000 heliconsoft.com. MacOS (Terminal): traceroute heliconsoft.com ping -c 30 -s 1000 -i 0.5 heliconsoft.com. Jun 22, 2020 Astro Pixel Processor is my goto software for my deep sky astrophotography and I decided to go with the renter’s license to always work with the latest version of the software. The interface is easy to navigate, options are explained by text messages that appear when you hover on the options with the mouse, and the different tabs are numbered.
In astrophotography you cannot avoid post processing your images, so stacking and editing your images serves three main purposes:
- Reduce noise and deal with light gradients and vignetting.
- Improve signal to noise ratio.
- Reveal the faint details in the image.
Image stacking is the technique used to improve the signal to noise ratio, and it is the only noise reduction method that will boost the image details rather than smear them out.
In this article, we will discuss some of the most popular software available for astrophotography image stacking.
Note: Don’t miss the detailed video at the end of this article, It was created to help show you how to quickly start using some of the stacking software mentioned in this article.
Click here to skip to our Image Stacking Demo Video.
What Does Stacking Photos Mean?
The concept behind image stacking is simple, but to appreciate how it works, there are a couple of things we have to consider:
- A stack can be visualized as a pile of images all stacked one on top of the other;
- Each digital image is formed by a set of pixels, all having a certain value: dark pixels will have a lower value than the bright ones;
In the simplest form of image stacking, the pixels values for all images in the stack are averaged to produce a single image.
What is the purpose of stacking photos?
The result is a single image with improved signal to noise ratio, i.e., with better details and lower (random) digital noise and better details.
The scheme below illustrates the concept.
If the considered digital noise affects the pixel values randomly across the stack, then the result of averaging the stack is that the random component of the noise to the pixel value is significantly reduced.
ISO noise and Luminance noise and Chrominancenoise are examples of digital noises that are random.
The image below shows a real-life example from stacking 30 images from my Sony RX10 bridge camera taken at ISO 6400. As you can see, the original images showed a greater deal of noise (grain) than the stacked one.
The More Images You Stack, The Better
The more images you stack, the cleaner the resulting images are, as shown in the comparison below.
While Image stacking creates a cleaner image, it often softens the image: digital sharpening techniques are then used to recover sharp looking details.
Finally, bear in mind that the progression of image quality is not linear.
If stacking 4 images improves the image quality of 50% respect what you got by stacking only 2 images, to improve a further 50% the image quality from stacking 50 images, you may need to stack 300 images or more.
Image Stacking And Movement
If nothing moves between shots, like in the previous real life example, implementing image stacking is very simple: just group the images and average them to smooth out the noise.
With a moving subject, grouping and averaging the images will not only smooth out the noise, but also the subject itself.
This is the same principle for which long exposures of passing traffic and crowd result in a street image without cars nor people.
This effect is amplified with the number of images used, and the moving subject could simply disappear from the stacked image.
To resolve the issue, you have to align the images based on their content before stacking.
Due to image alignment, you may have to trim the edges of the stacked image to get rid of artifacts, but your target will not be lost.
Note that while in theory you can stack images of a static scene taken with the camera on a tripod, in reality, those images will probably differ at the pixel scale due to micro-movements. It is always beneficial to align the images before stacking.
How To Shoot For Exposure Stacking Your Images
Image stacking can be done with any camera and even camera phones and with images in both RAW and JPEG format.
Nonetheless, some things can be done to improve the final result:
- Lock the focus, so that the camera will not hunt for it between images. This will also help to keep the focus consistent through the shooting sequence.
- Keep the same settings, in particular shutter speed, aperture, and focal length: you don’t want to change the camera field of view during the sequence, nor the brightness of the images or the depth of field.
- If you are shooting on a tripod, disable image stabilization. If you want to shoot handheld, do so only for short sequences at very high shutter speed.
Image Stacking In Astrophotography
Related:Astrophotography Software & Tools Resource List
As said previously, image stacking is a standard technique implemented in any astrophotography editing workflow for,
- A star field from a fixed tripod.
- A deep sky object from a tracking mount.
- The Moon handheld.
- A starry landscape from a fixed tripod or tracking mount.
Every astronomy image will benefit from image stacking.
List Of Photo Stacking Software For Astrophotography
Here is a list of software used in astrophotography for image stacking.
Adobe Photoshop
Complete Image Editor Commercial – Subscription Plan Photography Bundle $9.99 / Month Mac OS X, Windows
Pro
- Versatile
- Available for Mac and Windows
- In bundle with Adobe Lightroom CC, Bridge, Camera Raw, and web space
- Many action packs and plugins available for astrophotography
Cons
- Subscription Plan only
- Can’t be used to calibrate light frames
- Stacking capabilities are somehow limited
If you are interested in photography, chances are you know Adobe Photoshop is the standard in the industry and does not need introductions.
With Adobe implementing a subscription plan for their applications, if you are using Lightroom CC for your everyday photography, your plan subscription will also include Photoshop CC and Bridge CC.
And for astrophotography, Photoshop is what you need. Lightroom cannot stack your images nor perform the histogram stretching, two crucial steps in the editing workflow for astrophotography.
In this article, we have already covered in detail how to stack astrophotography images with Photoshop.
Sequator
Deep Sky And Starry Landscape Stacker Freeware Windows
Pro
- Free
- Easy to use
- Fast
- Suitable for both Starry Landscapes and Deep Sky images
- Can create Star Trails
Cons
- Windows only
- Limited set of options
- Not suitable for Planetary astrophotography
Sequator is an easy-to-use and intuitive astrophotography software for stacking both starry landscape and deep-sky images. It can also be used to create star trails.
While not as advanced as other stackers, it nonetheless allows you to calibrate your light frames with dark and flat calibration frames. It also allows you to remove light pollution, reduce noise, and perform other simple tasks on the stacked image.
Starry Landscape Stacker
Starry Landscape Stacker Commercial, $39.99 Mac OS X
Pro
- Fast
- Easy to use
Cons
- Mac Os X only
- Does not read RAW files
If you are into starry landscapes and you are a Mac user, Starry Landscape Stacker is a must-have.
Easy to use, it allows you to stack and align the sky and the foreground independently by letting you easily mask the sky.
Unfortunately, the software lacks the support for RAW formats, thus forcing you to convert your RAW images in the more heavy TIFF format.
Aside from that, it works very fast and the final image is of good quality. You can also save the sky only, which is useful to further edit the shot in Photoshop or similar editors.
Starry Sky Stacker
Deep Sky Stacker Commercial, $24.99 Mac OS X
Pro
- Fast
- Easy to use
Cons
- Mac Os X only
- Does not read RAW files
- Basic
Starry Sky Stacker is Starry Landscape Stacker brother and it has been created to stack deep sky astrophotography images.
As Starry Landscape Stacker, Starry Sky Stacker is very easy to use and intuitive, although very basic.
If you are a casual star shooter and a Mac user, this could be a good choice for you.
Deep Sky Stacker
Deep Sky Stacker Freeware Windows
Pro
- Free
- Easy to use
- Fast
- Full light frames calibration
- Features Comet stack modes
- Can Drizzle
- Many advanced stack options and methods available
Cons
- Windows only
- Post-processing is quite limited
- Not suitable for Starry Landscapes nor for Planetary astrophotography
Deep Sky Stacker, better known as DSS, is arguably one of the most widely used software to calibrate and stack astrophotography images.
With DSS, you can fully calibrate your images with Darks, Flats, Dark Flats, and Bias calibration frames for the best results possible. Light frames are analyzed and scored by quality so that you can decide which percentage of best images you can stack (Best 75% by default).
A very interesting feature is that with DSS, you can easily combine images taken during different imaging sessions, to produce images of higher quality.
Autostakkert!
Planetary Stacker Freeware Windows
Pro
- Free
- Easy to use
- Suitable for Planetary, Lunar and Solar images
- Stack full planetary disk and lunar surface close-ups
Cons
- Interface a bit confused
- It does not offer wavelet sharpening
- Windows only
Autostakkert!, also known as AS!, is a very popular free software among the solar system astrophotographers. With AS! it is easy to stack both images showing the full Planetary (or Lunar or Solar) disc and images showing lunar surface close-ups.
The interface is a bit confusing, particularly in the beginning, but it is easy to navigate through the different steps for the stacking.
Unfortunately, AS! does not offer wavelet sharpening, which is a widely used technique in planetary and lunar astrophotography. For this, you can load your stacked image in Registax, another freeware software for Windows only that, sadly, is now “abandoned-ware.”
Lynkeos
Planetary Stacker Freeware Mac OS X
Pro
- Free
- Has deconvolution and wavelet sharpening
- It is probably the only freeware planetary stacker for Mac OS X
Cons
- Not very intuitive
- Somewhat slower than Autostakkert!
Lynkeos is perhaps the only freeware planetary stacker software for Mac OS X, sparing you from turning to Windows for using Autostakkert!.
The interface is quite intuitive to navigate, but not when it comes to performing the different tasks.
On the other hand, it offers a deconvolution method and wavelet sharpening, a must-have for a planetary stacker. Definitely worth having a look at it if you are a Mac user.
SiriL
Deep Sky Astrophotography Editor Freeware Mac OS X, Windows, Linux
Pro
- Free
- Cross-Platform
- Active development
Cons
- A bit convoluted and not as intuitive as other stackers
SiriL is a freeware, cross-platform, astrophotography package that will let you calibrate, stack, and develop deep sky astrophotography images.
While not as easy and intuitive as Sequator or DSS, it offers a lot of options and produces good results. There is an active community, and it is under constant development.
Astro Pixel Processor
Deep Sky Astrophotography Editor Commercial $60/Yr Renter License Or $150 Owner License Mac OS X, Windows, Linux
Pro
- Full-grown astrophotography package
- Fairly easy to use
- Mosaics are created with ease and are of great quality
- Active and constant development
- Cross-Platform
- 30-days Trial period
- Affordable yearly subscription
Cons
- Only for deep sky astrophotography
- No Comet stacking mode
With Astro Pixel Processor (APP), you step in the realm of full-grown astrophotography packages, with many advanced options and methods to calibrate, stack, and post-process your deep-sky images.
Compared to PixInsight (PI), the software benchmark for the category, APP is cheaper and way easier to use, which makes it one of the best PI alternatives.
If you decide to buy it, you can choose between the renter’s license for $60/yr, to always get the latest version of APP, or the owner’s license for $150, but you will have to purchase the license again for major update releases.
PixInsight
Astrophotography Editor Commercial – €230+VAT Mac OS X, Windows, Linux
Pro
- It has all you need for astrophotography
- 45 days trial period
- A lot of tutorials and information available
Cons
- Expensive and without subscription plan
- Extremely steep learning curve
- Long and convoluted process
- Needs a powerful computer
When it comes to astrophotography, PixInsight is the software of reference against which all others are measured. It offers everything you may possibly need to produce pro graded images, and it is objectively the best software in the field.
But user experience can be frustrating, as the learning curve is very steep, the editing is long and convoluted, and your computer must be quite recent and powerful to make it run smoothly.
The €230 + VAT price tag is also quite steep: sure it is worth every penny, but this makes PI be even more the software of choice for professional and keen amateur astrophotographers.
A Comprehensive Demo About Image Stacking
In this video, I show you how easy it is to wet our feet with image stacking.
This is particularly true if you use Starry Landscape Stacker, Sequator, Deep Sky Stacker and Autostakkert!, as I showed in the video below.
Free Mac Photo Stacking Software Free
Conclusion
Image stacking is one of the crucial steps in the astrophotography editing workflow.
You’ll need the appropriate stacker for each type of astrophotography: starry landscapes, star trails, or deep-sky and planetary images.
In this article, we have covered the most popular astrophotography stackers available on the market, both freeware and commercial.
And while Windows users have the more extensive choice, some notable stackers are available for Mac and even Linux users.
Post-processing astrophotography images is mandatory: you cannot avoid it. It can be a fairly long and technical process, but it is necessary to squeeze out the most you can from your images.
Everything begins with pre-processing your images, a step including image calibration and image stacking, which we have already covered in this article.
After that, it is time to post-process your stacked image with your software of choice. In this article, we will discuss the different options that are available to post-process your astrophotography images.
Note: Don’t miss the detailed video at the end of this article, It was created to help show you how to process your images with some of the software mentioned in this article.
Click here to skip to our Image Processing Demo Video.
What Does Post-Processing Mean In Astrophotography?
In astrophotography, the post-processing includes steps that are crucial to the quality of the final image. Those steps can be summarized as:
- Histogram stretching
- Gradients and light pollution removal
- Stars color calibration
- Stars reduction and Stars removal
- Sharpening and noise reduction
- Final tweaks
Of the steps mentioned above, it is worth to spend a few words on the Histogram Stretching, as it is of utmost importance in deep-sky astrophotography.
What Histogram Stretching Is And Why You Need It
With image stacking, you have combined all your light frames (the actual images of the sky) into a single image with an enhanced signal-to-noise ratio.
With deep sky astrophotography, this stacked image can be surprisingly dark, with only a few bright stars visible.
There is nothing wrong with it, as all the details and information are there, but hidden in the dark background. And this is why this process also goes under the name of background extraction.
Histogram stretching can be done manually using Adobe Photoshop or in automatic/semi-automatic way using astrophotography software such as Astro Pixel Processor, Star Tools, or His Majesty PixInsight.
A rigorous explanation on how digital data are recorded and how the histogram works can become fairly technical and is beyond the scope of this article.
To keep it simple, let’s say that when you perform the stretching of the histogram, you are broadening the histogram. Thus pushing details that were crammed in the blacks towards the middle tones.
And you do that slowly, in small steps, to ensure retaining the best possible image quality.
The process allows us to take full advantage of the image stacking process, and it results in a cleaner, brighter image with a lot of details that were not visible (or barely visible) in the single exposures.
Stars Reduction / Stars Removal
Star reduction is another process that is standard when editing deep-sky astrophotography.
While it seems odd that you want to shrink or remove stars from a photo about stars, this process aims to make the multitude of visible stars in the image less imposing and distracting.
By reducing enlarged stars due to the histogram stretching and by removing the smallest stars, you make the deep sky objects in the image more visible, as shown in the image below.
The procedure is particularly useful when shooting deep-sky objects, such as nebulae, that are in the Milky Way Band.
Software For Astrophotography Post-Processing
We can group the software for astrophotography post-processing in two categories:
- generic photo editors, such as Photoshop, Gimp, Affinity Photo, etc.
- Astrophotography editors, such as StarTools, Nebulosity, Astro Pixel Processor, Pixinsight, etc.
The main advantage of generic photo editors over specific astrophotography editors is versatility.
With a generic photo editor, it is easy to post-process all kinds of astrophotography, from deep-sky imaging to lunar and planetary shots, passing for star trails and starry landscapes.
In this article, for example, we discussed how to stack starry landscape images in Photoshop.
Not many astrophotography editors are this flexible.
Here is a list of software that are most commonly used to post-process astrophotography images.
Adobe Lightroom CC
Generic Photo Editor Commercial From $9.99 Subscription Plan Windows, Mac OS X, IOS
Pros
- Easy to use
- Powerful image development and image organizer
- Easy integration with Photoshop
- Can use photographic plugins
Cons
- Can’t do the complex editing needed for astrophotography (histogram stretching, Stars Reduction, etc)
- Limited to cosmetic tweaks
Adobe Lightroom is a popular, easy to use and fairly powerful RAW developer and image organizer.
Its usefulness in astrophotography is somewhat limited, as you cannot perform complex tasks such as histogram stretching, advanced light pollution, and gradient removal, star reduction, etc.
On the other hand, it is a terrific editor for the final cosmetic tweaks to your image and to organize them in collections, per tag, and location. Lightroom is also great for color proofing your images before printing them.
If you are subscribing to the Adobe Photography Plan, you also have Photoshop CC included for free. And here is where things get interesting.
To get the best from the two worlds, load your stacked images in Lightroom, organize them in collections, and call Photoshop from within Lightroom for the astro-specific editing (histogram stretching, etc.).
Then make the final tweaks in Lightroom.
Adobe Photoshop CC
Generic Photo Editor Commercial From $9.99 Subscription Plan Windows, Mac OS X, IOS
Pros
- Versatile and Powerful Photo Editor / Image Manipulation Software
- Suitable for deep sky and planetary astrophotography as well as star trails and starry landscapes
- Astrophotography Action Sets and Plugins Available
- Subscription Plan with Photography Bundle
Cons
- Lacks Some Advanced Features for Astrophotography
Photoshop is one of the most commonly used software in the field of photography editing and image manipulation, and it can be used to post-process astrophotography work.
If you are a beginner astrophotographer, you are on a tight budget or you already own Photoshop, you should give it a try as all the basic post-processing steps can be performed in this software.
If you need more advanced features, you can also expand Photoshop capabilities thanks to many astrophotography related Action Sets, Plugins, and Panels.
Finally, with Camera Raw filter and other photographic plugins (like for smart sharpening and advance noise reduction), you can perform with ease all the final tweaks an image may need.
As a Photoshop user, I tried many plugins and action sets for astrophotography, and here is my must-have extensions list.
Astronomy Tools by ProDigital
Actions Pack For Deep Sky Astrophotography Commercial $21.95 Windows, Mac OS X
A rich set of actions suitable for post-processing astrophotography images. The set includes actions such as star reduction, enhanced DSO, light pollution and color gradient removal, sharpening, and noise reduction.
Photokemi’s Star Tools by Ken Mitchel
Actions Pack For Deep Sky Astrophotography Commercial $14.95 Windows, Mac OSX
Similarly to Astronomy Tools, this action set is most useful for deep space astrophotography.
It offers advanced star removal and star reducing actions, semi-automatic histogram stretching, different sharpening and noise reduction actions, as well as actions such as nebula filters and star color enhancement.
There is also a set of extra actions, available for $6.95.
GradientXterminator by Russell Croman
Plugin For Deep Sky Astrophotography Commercial $49.95 Windows, Mac OS X
This plugin is a gradient removal tool that is easy to use and extremely effective. Despite a rather steep price (a trial is available for you to test the plugin), this is a terrific add-on for Photoshop, if you are serious about deep-sky astrophotography.
Mar 31, 2020 An eGPU lets you do all this on your Mac: Accelerate apps that use Metal, OpenGL, and OpenCL. Connect additional external monitors and displays. Use virtual reality headsets plugged into the eGPU. Charge your MacBook Pro while using the eGPU. Use an eGPU with your MacBook Pro while its built-in display is closed. Mac pro video card.
Hasta La Vista Green! (HLVG) by Regelio Bernard Andreo
Plugin For Deep Sky Astrophotography Donationware Windows
Despite its old age, this plugin is still useful, and it does an excellent job of removing green noise and the green casts such noise may cause in some images.
Astro Panel By Angelo Perrone
Panel For Starry Landscape And Deep Sky Astrophotography Commercial Windows, Mac OS X
Astro Panel consists of a rich set of functions and methods that produce high quality starry landscapes and Milky Way images.
It is also easy to process Deep Sky Photos thanks to advanced functions for reducing digital noise and hot-pixels, eliminating the gradient, managing artificial flat, and much more …
Furthermore, astronomical images aside, you can use the Astro Panel to edit classic landscape images too.
Affinity Photo
Generic Photo Editor Commercial $49.99 Windows, Mac OS X, IOS ($19.99)
Pros
- Affordable
- Powerful
- The interface and commands are similar to Photoshop for an easy switch
- Suitable for deep sky and planetary astrophotography as well as star trails and starry landscapes
Cons
- Lacks third-party actions sets, plugins and panels
Affinity Photo from Serif Lab is a great, affordable alternative to Photoshop, and you do not need to pay for a subscription plan.
With Affinity Photo, you can carry out with ease all of the basic astrophotography post-processing.
But since there are no plugins, action sets, and panels to help you out, you have to learn to do things manually, even the more advanced tasks such as star reduction.
Gimp
Photo Editor Freeware Windows, Mac OS X, Linux
Pros
- Freeware
- Great community and lot of info available
- Powerful
- Suitable for deep sky and planetary astrophotography as well as star trails and starry landscapes
Cons
- Interface a bit confused
- Lacks third-party actions sets, plugins and panels
Gimp is the historical freeware alternative to Photoshop. Since it is freeware and on the market for many years, there is a big community of users, so it is easy to find relevant tutorials and guides to help you out.
The software has a slightly confusing interface, particularly if you are trying to switch from Photoshop, but it is powerful enough to let you edit your astrophotography images with ease.
Unfortunately, there are no third-party action sets, plugins, or panels to help you automate some tasks. As with Affinity Photo, you have to learn how to do everything manually.
Star Tools
Astrophotography Post-Processing Tools Commercial $45 Windows, Mac OS X, Linux
Pros
- Affordable
- Multiplatform
- Offers many advanced tools
- Trial without time limit
Cons
- Interface bit confusing
- Convoluted workflow
- Slower than other software
StarTools is a deep-sky post-process editor that does everything you need except the initial light frame calibration and stacking.
Once you have the stacked image from, say, Deep Sky Stacker, you can post-process it in StarTools, taking advantage of the many tools the software has to offer.
The interface is a bit confusing, and it may take a while to get used to the convoluted editing workflow.
Fortunately, the trial version never expires, so you can take all the time you need to experiment with StarTools before deciding if it is for you or not. The only limitation of the trial is that you cannot save your results.
SiriL
Multipurpose Astrophotography Editor Freeware Windows, Mac OS X, Linux
Pros
- Freeware
- Multiplatform
- Active Development
- Suitable for different kinds of astrophotography
- Fairly easy to use
- Powerful full-grown astrophotography software
Cons
- Develop the image is a lengthy process
- Interface a bit confused
I’m no expert with SiriL, but it is probably the only full-grown astrophotography editor that is freeware and multiplatform.
Siril will allow you to perform all the essential steps in your astrophotography editing workflow, from image calibration and stacking to (manual or auto) histogram stretching and post-processing.
Since it is free, if you are looking for an astrophotography package, SirilL is worth downloading and having a go with it.
Nebulosity
Deep Sky Astrophotography Editor Commercial $95 Windows, Mac OS X
Pros
- Capable full astrophotography editor
- Can calibrate and stack your images
- It offers many advanced tools
Cons
- Not abandonware, but development is somehow slow
- The interface feels old and not very user friendly
Nebulosity 4 was my first software specific to astrophotography. It is intended for deep sky astrophotography and is fairly easy to use.
It offers a good way to calibrate and stack your images, and you can use it for stretching the histogram, tighten the stars, calibrate the background colors, and perform sharpening and noise reduction.
But the interface is not as intuitive, it looks “old,” and while development is there, it is not as quick compared with other software.
Astro Pixel Processor
Deep Sky Astrophotography Editor Commercial €60/Yr (Renter’s License) Or €150 (Owner’s Renter) Windows, Mac OS X, Linux
Pro
- Great deep sky astrophotography package
- Powerful
- Easy to use
- Batch processing
- 30-days free trial available
- Suitable for creating stunning mosaic with ease
- Active development
- Rental license available
Cons
- Vignetting removal tool could be better
- No Stars Reduction methods available
Astro Pixel Processor is my goto software for my deep sky astrophotography and I decided to go with the renter’s license to always work with the latest version of the software.
The interface is easy to navigate, options are explained by text messages that appear when you hover on the options with the mouse, and the different tabs are numbered.
This means that there is no guessing in establishing the best workflow: just follow the numbers from 1 to 6 and jump at the tab number 9 for post-processing the stacked image.
You can run all the steps once at a time or set them up and run all with a batch processing: this way, you can do other stuff while the software calibrates and stacks your images.
If you are looking for a way to edit your deep-sky images and create mosaics, I vouch for Astro Pixel Processor.
PixInsight
Multipurpose Astrophotography Editor Commercial €230+VAT Windows, Mac OS X, Linux
Pros
- The best and most complete astrophotography editor on the market
- Multiplatform
- Suitable for Planetary and Deep-Sky astrophotography
- 45-days free trial available
Cons
- Expensive
- Extremely steep learning curve
- Requires a powerful computer to run smoothly and conveniently fast
I will be honest with you: I requested a trial (and it was granted twice), but both times I ran away from PixInsight screaming in despair.
Not that PixInsight is bad or lacks crucial functions, but because it is very complicated to use for beginners and the learning curve is very steep.
Granted, PixInsight, being the software of refinement for the category, there are tons of tutorials and guides online (Light Vortex Astronomy has some of the best ones and are free). But you need to spend a lot of time in front of your computer, particularly if you have an old one.
But if you can master it, you will be rewarded with Pro-grade deep sky astrophotography images.
A Comprehensive Video About Post-Processing
In this video, I show you how to post-process a deep sky image using some of the software discussed in this article.
While it is not a complete tutorial in post-processing deep sky images, it gives you a feeling of how easy (or not) is to use those software and where they differ.
Conclusions
Stacking astrophotography images is only the first step in the lengthy astrophotography editing process. In this article, we have discussed the different software that is available to post-process the stacked image to obtain a compelling image of the night sky.
Some are free, some are commercial, some are specific to deep sky astrophotography while others are generic photography editors, and they all have their pros and cons.
This guide will help you to decide which software is best for you.
Personally, I am a fan of Astro Pixel Processor for deep sky astrophotography, as it is powerful and easy to use, and of Photoshop for its flexibility.