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Andromeda Galaxy Astrophotography Tutorial

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In this post, I’ll walk you through the image processing steps I used to create the image of the Andromeda Galaxy shown below. This astrophotography tutorial uses Adobe Photoshop to bring out the intense colors and detail of a galaxy that was photographed using a DSLR camera and a small telescope. 

You can follow along and process the exact same data I did (download here), or you can try these techniques on your version of the Andromeda Galaxy taken using your own equipment. If you choose to download my data and process it, you can skip straight to the Photoshop portion of this tutorial. 

This tutorial uses DeepSkyStacker and Adobe Photoshop. If you are new to this process, you may find the following DeepSkyStacker tutorial useful. The images used in this tutorial were captured using a Canon EOS 60Da DSLR camera with the RAW image type selected.

Messier 31 – The Andromeda Galaxy.

The equipment used for this shot:

telescope equipment

The camera and telescope equipment used for the photo on this page.

About the Image

This image was captured on a clear night under Bortle Scale Class 4 skies. A William Optics Zenithstar 73 telescope was used like a telephoto lens on my Canon DSLR camera. The telescope tracked the apparent movement of the night sky thanks to Sky-Watcher HEQ5 equatorial telescope mount. 

You can watch the complete journey leading up to this image in the following video: Photographing the Andromeda Galaxy. The images were collected while we camped under the stars on a beautiful August night. 

The final stacked image includes 67 x 2-minute exposures (2 Hours, 14 Minutes Total) at ISO 800. Calibration frames were used (15 x darks, flats, and bias) to help calibrate the final integration. 

Andromeda Galaxy Image Processing Tutorial

The goal of the this image processing tutorial is not for you to follow my process step-by-step to achieve the same result, but to get a better understanding of the tools and techniques I use to edit my astrophotography images. No matter what level of experience you have, I am confident that you will find a number of helpful tricks you can use while processing your own image of the Andromeda Galaxy. 

before and after photo

Assessing your Data

After collecting your images of the Andromeda galaxy with your camera, you need to organize the all of the files on your computer so that you can easily find them. I like to sort all of the picture files and calibration frames into separate folders.

Create a folder for your light frames, dark frames, bias frames, and everyone’s favorite, flat frames. The root folder should include the date the images were taken so you have all of the information you need to reference later including the moon phase and location.

You may also want to include the telescope, camera, and filter that were used in the folder name, as these details may be hard to remember years later. Here is a look at the folder structure for my data on the Andromeda Galaxy.

folder structure

Make your life easier by taking the time to organize your images and calibration frames into folders.

You may find it useful to go through your light frames in a RAW image preview software such as Adobe Lightroom or Adobe Bridge. Delete any frames that have airplanes, or satellites passing through them, or that are not the full exposure length. If your tracking accuracy and autoguiding were successful, you should not have to delete any frames due to poor tracking. 

With the files organized and easy to find, we can now import the image data into DeepSkyStacker for calibration and integration. This will create an intermediate file that can then be processed extensively in Adobe Photoshop. 

Stacking and Calibration

DeepSkyStacker will allow us to calibrate our data using support frames, and improve the signal-to-noise ratio of the final image through integration. The software will automatically align and register the images on top of one another, to reduce noise and increase the signal (light) in the image.

To start, select all of your light frames (the actual pictures) by clicking the Open picture files button on the top left of the screen. This is where you will choose all of the images on the Andromeda Galaxy you would like to stack. If you have organized your images and folders neatly, and have filtered out any images that should not be in there, this process will be very easy. 

deepskystacker

Load all of your light frames (picture files) into DeepSkyStacker.

You will then need to repeat the process, for your calibration frames. Click on the buttons for dark frames, flat frames, and bias frames in the top left-hand menu of DeepSkyStacker. I recommend using at least 15 support frames to properly calibrate the image for further processing. 

You can review the details of your image files in the lower portion of the screen.

This is a great time to check to make sure the following:

  • Your light frames are all the same exposure length and ISO
  • Your dark frames match the exposure length and ISO of your lights
  • Your Bias frames are the fastest exposure length possible
  • You have loaded at least 15 flat frames into DeepSkyStacker

image stacking

Review the details of your image files in the lower half of the DeepSkyStacker dashboard.

If everything looks in order, you can go ahead and click check all, followed by Register checked pictures. From here, we will need to make sure that a few key settings are used so that DeepSkyStacker can properly integrate and calibrate the image data. 

Register and Stacking Settings

Use the Register Settings shown in the image below as a reference. Because we have used all of the recommended calibration frames, and have pre-screened the images, these settings should work well. Feel free to try using the exact settings I have used to stack the image, including the sigma-clipping combination method to stack the light frames. 

deepskystacker settings

Recommended Settings in DeepSkyStacker.

You can change the Star detection threshold in the advanced tab of the Register Settings. The setting you use will depend on the type of data you are stacking. For this image, I suggest using a threshold of 25%, as it will speed up the stacking process significantly, and 456 stars are more than enough to successfully register the image. I have always kept the “Reduce the noise by using a Median Filter” option checked. 

star detection threshold

As for the Stacking Parameters (which can be accessed by clicking the button in the Register Settings box), I suggest leaving the default settings in place under the light, dark, flat, and bias tabs. You can select the Enable 2x Drizzle option if you want, but be warned that your computer will kick into overdrive, and the output file will be massive. (learn more about the benefits of using drizzle). 

stacking parameters

Now, click the OK button and review the final Stacking Steps of your image, and the estimated total exposure time. The total integrated exposure time for my image of the Andromeda Galaxy is 2 hours, and 14 minutes. 

Your stacked image of the Andromeda Galaxy may look very different than mine. Everything from the amount of exposure time invested in the image, to the filter used will affect this. 

The resulting image of the Andromeda Galaxy shown below has a typical look to broadband, color images shot using my DSLR camera. This is our intermediate file, that is now calibrated to reduce much of the noise and artifacts present in a single exposure. 

astrophotography image

The stacked 32-Bit TIF file created by DeepSkyStacker.

The integrated data now has a much better signal-to-noise ratio, which will make the processing and manipulation techniques in Adobe Photoshop much more effective. The final processed image will look much different than the version you see at this stage.

Image Processing in Adobe Photoshop

Adobe Photoshop is powerful tool for processing astrophotography images. It is a robust graphics software designed primarily for photography and design, but many amateur (and professional) astrophotographers use Photoshop for astrophotography image processing. 

Adobe offers a subscription service for their complete Creative Cloud Suite, or for stand alone products such as Adobe Lightroom or Photoshop.

Adobe Photoshop CC

Download Photoshop CC (Single App Plan)

Open the Stacked TIF Image

The first thing we need to do is open the file that DeepSkyStacker created using all of our pictures and calibration data. By default, DeepSkyStacker will output the intermediate file as a 32-bit .TIF, in the destination you have selected in the settings.

The default name of this file will be Autosave.TIF. You can change this file location in the output tab of the stacking settings option.

Alternatively, you can save the stacked .TIF file by clicking Save picture to file, at which point it will convert the image to 16-bit mode. We need to convert the 32-bit image to 16-bit to fully process the file in Adobe Photoshop anyway.

Now it’s time to open the TIF file you created in Adobe Photoshop. If you are opening the Autosave.TIF file that DeepSkyStacker created on it’s own, you first need to convert the image to 16-bit, by clicking Image > Mode > 16-Bits/Channel.

You will now have complete access to all of Photoshop’s tools to manipulate the data.

Crop and Initial Curve Stretch

I like to start by cropping the image slightly, just enough to remove any stacking artifacts around the edges of the image. This can create an inaccurate histogram reading, and you wouldn’t want to include these edges in your final image. You can use the Crop tool, or simply select the area you would like to keep (98% of the image), and click Image > Crop from the main menu. 

The first change we will make to the data is a simple curves stretch. Using the Curves tool (Image > Adjustments > Curves), perform a basic curve stretch using the image below as a reference. Now, the data is non-linear, and has been manipulated to help us better see the dynamic range of this object. All of the amazing deep sky astrophotography images you have ever seen were “stretched” like this. 

curves stretch

My initial curves adjustment.

For this object, it is important that we do not over-stretch the core of the Andromeda Galaxy. It is the brightest area of the object, and details surrounding it could easily be lost. To avoid this, you can either blend in shorter exposure images of the core using a layer mask, or isolate this area (again, using a mask) so that you do not stretch this data as far as the surrounding details.

In the next step, I’ll show you an easy way to selectively stretch all of the areas of the image except the bright core. 

Selective Curve Stretch

To start, we’ll select the brightest area of the image using a mask. Click on Select > Color Range > Sampled Colors. Now, use the eyedropper tool within the Color Range dialog box to select the nucleus of the Andromeda Galaxy. 

Feel free to use settings similar to the ones below on your image. This will create a rough mask that we now need to refine.

color range

Now, navigate over to the Select and Mask tool (Select > Select and Mask) to soften the edges around the selection. This is an important step, because we need to create a smooth transition between the areas at the edges of the mask. 

Once you are happy with the amount of feathering around the mask (using the Feather slider in the Select and Mask dialog box), you can click OK, and the selection mask will activate. Now that we have defined the area we want to leave untouched, we need to click Select > Inverse to apply our curves adjustment to. 

Perform a modest curves stretch as you did in the last step, and notice that the areas we have masked off (the nucleus of the Andromeda Galaxy) remain unchanged. You may want to make several iterations of this process, making small curves stretches each time. 

Before/After

Before and after making a selective curves adjustment. 

If you were too aggressive in your selective curve stretch, you will create an unnatural looking transition between the core of the galaxy and the mid-tone areas. To avoid this, find a balance between the amount of feathering at the edges of your mask and the amount of curve adjustments you make. 

The same process of masking the bright core of the galaxy can be used on the surrounding stars in the image. This technique is a great way to pull your data forward without bloating the stars. 

Color Balance the Image 

At this stage we will balance the color of the image by setting the black point, and the white balance. Start by creating a Threshold Adjustment Layer (Layer > New Adjustment Layer > Threshold). This creates an exaggerated view of the image showcasing the brightest and darkest areas of the image.

Threshold Adjustment Layer

A threshold adjustment layer used for setting the black and white points. 

We’ll use this layer to plot our black and white points of the image. The black point is used to balance the background night sky to a neutral grey, while the white point is used to set a natural white color as we know it on Earth from the Sun. 

Using the slider in the properties tab of the threshold adjustment layer, choose an area of the sky that contains no stars, and is not touching the galaxy. Use the Color Sample Tool (found in the main toolbar) to plot 2 points on the image where there is nothing but dark sky.

Make sure that the Sample Size (found at the top left of the screen) is set to 5 by 5 average for the best results. 

Setting the Black and White Points

Now, plot a point on the image that is the brightest “white” area of the picture. In most cases this is a star, but this time I have chosen to use the center of the galaxy core to set the white balance. For the most accurate rendition of colors, you will want to use a star that is the same type (G2V class) as our Sun.

These plotted points will now give us a reading of the pixel information and currunt balance of colors in the image. To see this information, turn off (or delete) the threshold adjustment layer, and open the Info window (Window > Info).  

At this stage, we just need to balance the colors out a bit. If your image is like mine, it is very brown and ugly at the moment. We can balance the colors by adjusting each color channel independently and matching the values of our plotted points.

With the Info window open, click on Image > Adjustments > Levels. From the levels window, select each color channel from the drop-down menu and adjust the sliders. For my first levels adjustment, I have set the black point to read 20, 20, 20 across the RGB channels. These values will increase shortly, as we will pull the data forward even more. 

color balance

This is a good time to save the image. For all further edits, it is wise to create new layers on top of the original. This way, you can save the file with each adjustment made on its own layer. Label each layer with the adjustment you have made, and then you can save the complete .PSD file with the ability to go back and edit at any stage later. 

Targeted Curves Adjustment 

A powerful way to make a targeted curves adjustment in Adobe Photoshop, is to hold down CTRL on your keyboard and plot a temporary reference point. With the Curves window open, hold down CTRL and click an area of the background sky. Now, holding down CTRL once more, click an area of the Andromeda Galaxy that you would like to brighten (the mid-tones at the edges of the galaxy),

If you noticed, the histogram on the Curves window now has two points plotted on the graph. You can now “pull” at the data with a targeted approach, as you now know where specific pixel data lies in the graph. The goal is to bring out the mid-tones, without bringing up the dark sky, or disturbing the bright core of the galaxy.

Curves Photoshop

Making a curves adjustment with plotted points on the histogram. 

At this stage, we can now see a lot more of the galaxy structure. The image is far from done, but it’s nice to see all of the interesting details of our deep sky object. This is another great time to save the image. I also like to use the History state feature of Adobe Photoshop (Window > History) if I ever need to go back and make small changes during my process.

Saturation Boost

You may want to increase the saturation of the colors of your image. I find the best way to accomplish this is to create a Hue/Saturation Adjustment Layer. We need to define specific areas of the image to apply this effect to, and the Color Range Tool is a convenient option. 

Go to Select > Color Range > Highlights, and adjust the slider to define the areas of light we would like to increase the color of. In my case, I have chosen the bulk of the highlights, as I would like to increase the saturation of the galaxy as a whole, and the brightest stars in the field. To refine the selection, you can use the Select and Mask Tool, or simply Select > Modify > Feather using a value of 1 or 2. 

With the selection active, go to Layer > New Adjustment Layer > Hue Saturation. Now you can adjust the Saturation slider to taste, boosting the intensity of the colors in your image. This is where your personal taste dictates the direction of the image. I would suggest not going overboard with your saturation boost adjustment. 

At this point, I recommend creating a visual merge (Shift + Ctrl + Alt + N + Eon the keyboard), and naming this layer “SATURATION”. If you have followed a similar path to me, your image and layers will look a little something like this:

Andromeda Galaxy Photoshop Tutorial

The Andromeda Galaxy with a selective boost in saturation. 

Minimize Stars

Minimizing the size of the stars in your image is a great way to draw more attention to your deep sky object. I find it to be one of the most dramatic differences between a good astrophotography image, and a great one. 

Reducing the size of the stars in your image is easy, but you will need to monitor a few things along the way. First create a new layer, and name it STAR MINIMIZE. That way, we can turn the layer on and off to see the difference it made. 

Start by using the Color Range Tool again, selecting Highlights from the drop-down menu. Adjust the slider so that most of the stars are selected, but not the entire disc of the galaxy.

The goal is to select only the stars, so we can apply a minimizing effect to them. We will need to refine this selection and remove the bright areas of the galaxy, as we want these areas to remain unchanged. 

Using the Lasso Tool (found in the main toolbar), hold down the ALT key, and draw around the areas of the Andromeda Galaxy that you do not want to apply a star minimizing effect to. Holding ALT will ensure that this action de-selects area of the selection. 

star minimize

Settings for minimizing stars with the minimum filter in Adobe Photoshop. 

Now, go to Select > Modify > Expand, and expand the selection by 1 pixel. You should notice that the “marching ant” selection has changed, and that there is now more room around the star selected. You may want to expand the selection by 1 more pixel, depending on the aggressiveness of the original selection made.

Next, go to Select > Modify > Feather, and use a Feather Radius of 1 pixel. This has softened up the selection around the edges, which is important for blending purposes. 

With our selection carefully refined, we can apply the star minimizing effect to the stars. Go to Filter > Other > Minimum, and use a radius of 1.0 pixels. Make sure that the Preserve option is set to Roundness and click OK. Click anywhere on the selection using the Lasso Tool to deselect it. 

Here is what my image of the Andromeda Galaxy now looks like with smaller stars.

Smaller Stars

Noise Reduction and Artifact Removal

If your stacked image includes 3+ hours worth of exposure time, chances are the noise is minimal. For my data, there is still quite a but of camera noise in the images, even using 67 light frames and calibration data. There is also an unnatural glow coming from the bottom of the image.

Let’s start with the noise. I prefer to use the noise reduction tool found within Adobe Camera Raw. To access this feature, click Filter > Camera Raw Filter. The noise reduction tool is found under the Detail Tab, and can be controlled using the Luminance slider under the Noise Reduction heading. 

Zoom into the image to about 200%, and experiment using different levels of noise reduction on the slider. You can also mask and sharpen the image using this tool, but I don’t recommend doing that yet (even though I did in the example). Here are the noise reduction settings I chose to use for my image of Andromeda. 

noise reduction settings

Use the sharpening tool found under the detail tab of Adobe Camera Raw. 

Now that the noise is under control, we can tackle the subtle glow at the bottom of the image. In this situation, I think the easiest way to correct this is by copying the top most layer, and reducing the brightness. Then, I can remove the areas of the image that I do not want to darken using a simple mask and the Eraser Tool

Odd gradients like this are some of the most challenging processing scenarios, and can usually be avoided with proper flat frame calibration. I’m not quite sure what went wrong this time (the horizontal banding indicates it could be something to do with the dark or bias frame signal), but luckily fixing a subtle horizontal gradient like this is not too difficult. 

Gradient Xterminator is a handy third-party plugin for removing gradients and vignetting in your images. This is the method I used on the Andromeda Galaxy image, although I have shared ways to remove gradients without Gradient Xterminator in the past. 

Using Photoshop Actions

I have installed a useful astrophotography image process Action Set to my version of Adobe Photoshop, and I find it exceptionally useful. The Astronomy Tools Action Set contains many time-saving, powerful actions you can apply to your image with the click of a button. You do not need these actions to create amazing images in Photoshop, but I find them to be very handy.

If you are using this action set, I like to run the “Enhance DSO and Reduce Stars” action at this point. It can make a dramatic difference to the image in a single click. It basically pulls the faint details of the galaxy forward, and applies another star minimizing effect the image. I prefer to set this layer to 50% opacity once complete.

You can also try running the “Make Stars Smaller” action, which should be used carefully as it can eat away at the stars in your image. 

Here is a look at each layer of the process, to give you a clear idea of when each processing technique took place.

processing steps

Each layer of the image is labelled with the processing step that took place. 

Selective Sharpening

It is wise to only sharpen the ares of your images that you intend to sharpen, and to not simply run a sharpen filter over the entire image. For example, you would not want to sharpen empty areas of the background sky, or the larger stars with a pleasingly soft glow. 

Again, we’ll use a mask selection to isolate the areas we would like to to sharpen. The Select > Color Range > Highlights method works well, and be sure to refine the mask with careful feathering.

The sharpening filter I enjoy most is the one found inside of Adobe Camera Raw. This tool features a number of useful options to apply just the right amount of crispiness to your image. You’ll find it under the Detail Tab of Adobe Camera Raw (Filter > Camera Raw Filter).

Andromeda Galaxy

Finishing Touches

From this point forward, you need to decide the overall story you want to tell with the image. You can apply subtle tweaks to enhance the details of the image you enjoy most, whether that is having tiny stars across the field, cool blues in the galaxy, or a well-defined core. It may take several astrophotography image processing sessions to understand what makes a great image in your eyes. 

You may want to adjust the orientation of the image, too. For the Andromeda Galaxy, I like to see it in a portrait orientation so the galaxy is on an angle. To me, this gives the Andromeda Galaxy more depth and better showcases its spiral structure.

One tip I’d like to share, is to process two entirely different versions of the image. This means starting from scratch, making subtly different decisions about each action along the way. Then, compare both processes of the image, and decide which one you like best. Often times, I will combine the two processed image together with the top layer at 50%. 

With the selective masking techniques I shared in this tutorial, you’ll have countless ways to process your image of the Andromeda Galaxy in the fashion that you prefer. 

astrophotography

I hope you have enjoyed this image processing tutorial on the Andromeda Galaxy. To keep up with my latest videos, tutorials, and equipment reviews, please subscribe to the AstroBackyard Newsletter

Download My Image Processing Guide

If you would like to learn about every astrophotography image processing technique I use in DeepSkyStacker and Photoshop, you can download my premium guide. The PDF download contains over 100 pages of the specific steps I take to process all of my images. The guide is available here.

image processing guide

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Essential Image Processing Video Tutorial

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This video may change the way your shoot and process astro-images forever. It covers the few simple steps needed to create an ultra high-resolution master frame with a high signal-to-noise ratio.  This tutorial covers the capturing, processing and production of gorgeous wide-field astrophotography images using a camera lens or small telescope. If you are a DSLR imager like me, many of the techniques you’ll see demonstrated in this video will make their way into your capturing and processing workflow.  Even if you focus more on deep-sky imaging with a large telescope, there is still much to take away from Tony’s practices. You might even learn a little bit more about about the way DSLR’s work, their limitations, and how to get around them to produce stunning images.

Self proclaimed “Lazy” Astrophotographer Tony Hallas discusses the basics of DSLR imaging and provides intermediate pointers for capturing and processing amazing images. In this video, Tony explains how he has learned to harness the powerful and sophisticated capabilities of Adobe Camera Raw (ACR) to handle the majority of his astrophotography image editing and processing. I will be implementing Tony’s techniques into my own workflow, and I will share my new images using his techniques as I capture them. Here is a Milky Way image processing tutorial that includes some of the methods Tony uses in Adobe Camera Raw. 

Signal-to-Noise Ratio (SNR)

The measure used in science and engineering that compares the level of a desired signal to the level of background noise.

DSLR Camera vs. CCD – Which is Better?

A DSLR and a CCD camera may seem similar, both essentially use a sensor to gather light photons.  However, there are several key differences that make these tools worlds apart. Each have their own benefits and downfalls. Some of the major advantages of a CCD camera over a DSLR are the specialized astrophotography features, such as a cooled and regulated chip temperature, and better handling of noise during long exposures.  The mono chip, combined with calibrated narrowband filters, provides extremely accurate colour control.

ATIK Mono CCD Camera for narrowband astrophotography with filters

In Tony’s opinion, narrowband imaging is the realm of CCD cameras, and not worth the time and effort of tackling with your DSLR.  It is not possible to produce an astronomical  image as deep and detailed with a DSLR as you would with a CCD. The major downside on CCD cameras is their steep learning-curve, and high price tag.  An entry-level CCD Camera will cost you upwards of $2,000.

What is the Best DSLR Camera for Astrophotography?

If you ask Tony, he’ll tell you it’s the full-frame, Canon EOS 6D. His was astro-modified by Hutech for astrophotography. My friend and fellow astrophotographer Phil owns this camera, and produces amazing results when combined with his ultra-portable iOptron Skytracker mount. You can view a photo he captured of the Milky Way at the bottom of this page.  I currently use my old modified Canon Rebel Xsi, but my next DSLR will definitely be full frame. Whether I spring for a used Canon EOS 5D Mark II, or the newer 6D, is yet to be decided.

Benefits of using a DSLR

The advantages of using a DSLR for astrophotography are many. The first is that it is easy to focus the camera using live-view. You can simply find a bright star, zoom-in by 10X and fine tune your focus whether it is through a telescope or on the camera lens. DSLR cameras do not use very much power.

I use an aftermarket battery grip that I purchased on eBay. These 2 small batteries will last an entire nights worth of imaging. You have the option of taking shorter exposures to adjust your frame and enjoy a quick preview of your subject. Instant gratification. The most important factor of them all is the fast setup, and minimal equipment.

If you plan on doing any travel astrophotography, chances are you will be using a DSLR and a lightweight tracking-mount. I believe that this is the reason DSLR astrophotography has become so popular around the world.

Image of the Andromeda Galaxy with a DSLR by Trevor Jones

Some of the drawbacks of using a DSLR for astrophotography are the lack of temperature regulation, the handling of colour using a bayer mask (RGB) and the primary noise source of “colour mottle”. 

Color mottle by Tony’s definition is horrible globs of red, green and blue artifacts that appear in a long-exposure DSLR frame.  In the video above he explains the steps he takes to remove the large amount of grain and noise in his long-exposure astro-photos. The process is known as dithering, which subtracts the noise data by taking frames slightly apart from each other, and then registering and stacking the data afterwards.

Best Camera Lens for Astrophotography?

The 4 camera lenses mentioned in this video that would make excellent choices for astrophotography purposes are the Canon 70-200mm f/2.8 L, Nikon 14-24mm f/2.8 G, Canon 15mm f/2.8 Fish-eye (not pictured) and the surprisingly high-performing Rokinon 35mm f/1.4

Tony noted that the Nikon 14-24mm was the best wide-angle lens, that he uses an adapter to connect to the Canon body.  You can browse insightful performance statistics about each lens including the amount of vignetting and resolution on the Photozone website.

The Rokinon Lens is 1/3 of the price of the big-name brands and scores top marks in the categories of vignetting and resolution.  As Tony says, this lens is a total sleeper.

Rokinon 35mm f/1.4 Lens for Canon Cameras 
 

Rokinon 35mm f/1.4 lens for astrophotography
The Resolution of the Rokinon 35mm Lens scored top marks from Photozone

 

Different examples of camera lens choices for astronomy photography

I personally enjoy the Rokinon 14mm F/2.8 lens for wide angle astrophotography. This lens is very affordable and can capture extremely wide swaths of the night sky with either a crop sensor or full frame DSLR camera.

So What Equipment do I Need for this Process?

As Tony describes in the video, there are some essential pieces of equipment and software to produce the high-quality images he is taking. Remember, you don’t have to jump straight to top-of-line equipment right away.  I certainly didn’t! This is merely a guideline for those wondering the exact equipment used in the video.

1.  Astro-Modified DSLR Camera such as the Hutech Modified Canon 6D
2.  High-Quality Camera Lens such as the Rokinon 35mm f/1.4
3.  Recent Version of Adobe Photoshop with Adobe Camera Raw
4.  Latest Version of the Registar Software

Adobe Camera Raw software and a Canon 6D DSLR
 

The Tony Hallas DSLR Processing Workflow

Tony uses Adobe Camera Raw for the bulk of his processing. He then combines the corrected images together using Registar, and back into Photoshop for final editing. His DSLR processing workflow is shown below:

1. Initial ACR batch processing and save as 16 bit TIFF to folder
2. Register frames in Registar and combine with median/mean function
3. High Signal-to-Noise ratio 16 bit TIFF imported into Photoshop for final processing

Chromatic Aberration and Vignetting

He begins his process by opening the first frame in a series of images and removing the chromatic aberration with the tool designated for this in Adobe Camera Raw. This is a powerful technique that can remove even severe chromatic aberration produced by inexpensive lenses. Next up is vignetting. The traditional way of dealing with vignetting was to shoot “flat” frames using an old white t-shirt to cover your camera lens or telescope, and shining a bright, evenly lit light into it. Try explaining THAT to your nosy neighbor watching you in your backyard. Tony simply uses the anti-vignetting tool in the Lens Correction tab of in ACR.

Noise Reduction and Colour Adjustment

The noise-reduction tool in ACR is comparable with powerful third-party plugins dedicated to this task. A liberal amount of luminance noise-reduction is applied in the example. He then opens the curves tab, selects the red colour channel, and reduces the amount of red (caused by light pollution) in his image. A small contrast adjustment is made next. Our instructor seems a tad rushed through this part of the tutorial, but if you are following along with the video it all makes sense.

A general rule of thumb when processing astro-images in ACR is to start from the right tab, and work your way left. Resist the temptation to start moving sliders in the far left tab right away.

Now that we have this one “perfect” frame with all of our adjustments, we can apply these settings to all of the frames at once using the “synchronize” command. This is the stage of the game Tony calls “halfway home”, where we have all of our images in the series with the exact same adjustments made.

Registar

I’ll start by saying that I have never used Registar. I use free software called DeepSkyStacker for registering my images, and Registar is listed at $150 US!  I will see if I can supplement this step with DSS before forking out 150 big ones for Registar.

In a nutshell, he tells Registar where to look for the image set, uses the default program settings, and goes for a coffee. (I like your style Tony!) Registar then goes through each image and accurately aligns each image star by star. This takes about 5 minutes. The next step is to click on “Combine Control” and select “Median/Mean” to average all of the frames together and create a neutral image. You can also take this process a step further by using the outlier rejection capabilities of Registar to remove unwanted objects such as a satellite trail.

The final combined image is created by Registar is impressive. The stacked image is smooth and free of grain, colour noise and spurious colors. This averaged image is now the Master Frame. A 16-bit TIFF with all of the adjustments made and a high signal to noise ratio.

An astronomical image with an improved signal to noise ratio

Final Processing in Adobe Photoshop

This is where your artistic freedom comes in to play. There are limitless ways to process your final astrophotography image, and this is definitely my favorite step in the entire process. The big difference this time is that you now have a very smooth, clean image to play around with. An image free of vignetting, chromatic aberration, noise, and properly colour corrected. I hope you got as much out of this tutorial as I did the first time I watched this amazing video from Tony Hallas.

You can visit Tony’s Website Here.

Wide-Field Astrophotography Image using Canon EOS 6D and Tony Hallas Processing:

 

Milky way galaxy photo taken with a Canon 6D and iOptron Skytracker.
The Milky Way – Photo by Philip Downey using Tony Hallas Processing Techniques

Phil is a member of my astronomy club and takes incredible astrophotography images using a Canon 6D and iOptron SkyTracker.  You can visit his blog here.

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LRGB Processing Technique for Orion

Astrophotography LRGB Processing Technique

A useful guide to processing the Orion Constellation using a DSLR Camera and Tripod

From the very moment this video started, I knew I was in for a real treat. The motion control time-lapse of the Milky Way moving across the sky was the perfect primer for this high production, quality tutorial. Lonelyspeck.com is an informative and beautiful website created by Ian Norman –  A full-time traveller and photographer. In the following video he will explain how to process a photo of the Orion Constellation using the LRGB processing technique. He stacks multiple exposures to reduce noise, corrects vignetting, and greatly enhances the contrast and colour of the photo.  The exact camera settings he used, including ISO, exposure length and aperture details are shared.

He uses nothing more than a regular tripod and a DSLR camera equipped with a standard prime lens. The location he chose for this tutorial was Red Rock State Park in California.  The initial processing steps take place in Adobe Lightroom, a different approach than I currently use. Based on this tutorial, I may need to incorporate Adobe Lightroom into my astrophotography processing workflow.

Another major difference in this photographer’s technique is the fact that he stacked the photos directly in Adobe Photoshop as opposed to a third-party software like Deep Sky Stacker. I have heard of a lot of astrophotographers who swear by this method. One thing to note is that stacking via “photomerge” in photoshop will consume a large amount of RAM on your system, and could result in a system crash. Be sure to have your work saved, and have some time set-aside for this process to take place.

One of the biggest factors in the amazing results Ian was able to achieve, was the pristine dark skies he was able to shoot in. It is not possible to bring out the faint details seen here from the city. I can’t wait to try this tutorial myself. I am amazed at how much detail he was able to pull out from such short exposures. I hope that you find this tutorial as invaluable as I did.

 
 

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