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Astrophotography Video Tutorial

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Astrophotography Video Tutorial

Astrophotography Video Tutorial

In my first ever astrophotography video tutorial, I take a crack at the Rosette Nebula using data collected in February 2014. I have plans of shooting a video about light frame acquisition in the future, but this one is about what happens after you have already captured your data.  This astrophotography video tutorial may be useful to anyone who has questions about the stacking process, and processing the created .TIF file in Adobe Photoshop.

I must admit, I learned a lot about how I could improve upon these videos in future during the process.  Putting together an online tutorial video using a particular piece of software is harder than it looks!  Nevertheless, I believe new astro-imagers will find some useful information in my video.

My astrophotography processing techniques

In the video, I discuss the importance of organizing and inspecting your raw image files before you dive-in to Deep Sky Stacker. The application I find most useful for this stage is Adobe Bridge.  I subscribe to the Adobe Creative Suite that includes all of the Adobe applications, so using Bridge as my default image viewer was a no-brainer.  I know that Adobe Lightroom is another popular choice for this purpose as well. Alternative methods for viewing RAW image files on your PC are Faststone Image Viewer, Canon EOS Utilities and installing the proper codec on your particular version of Windows to preview the files.  I have used Faststone Image Viewer and Canon EOS Utilities, but I have not tried the Windows Codec option.


Video Summary

Using Deep Sky Stacker, I register and stack over 2 hours worth of 3.5 minute light frames I captured of the Rosette Nebula with my Canon Xsi and ED80 Telescope. As always, dark frames are subtracted from the final image to produce a final image with a higher signal-to-noise ratio.  I then locate and open the 32 bit Autosave.tif file into Adobe Photoshop CC for further processing using helpful astrophotography plugins including Gradient Xterminator and the Astronomy Tools Action Set. The order of the actions I make when processing an astrophoto from the RAW image files to the final result are as follows:

  1.  Stack and register light and dark frames in DSS
  2.  Open Autosave.tif file in Adobe Photoshop
  3.  Slight Image Crop to remove stacking artifacts
  4.  Removal of gradient and vignetting via Gradient Xterminator
  5.  Levels Adjustment
  6.  Convert to 16-bit/channel image
  7.  Curves Adjustment
  8.  Astronomy Tools Action > Local Contrast Enhancement
  9.  Astronomy Tools Action > Enhance DSO and Reduce Stars
  10.  Astronomy Tools Action > Increase Star Colour
  11.  Astronomy Tools Action > Make Stars Smaller
  12.  Balance neutral background sky colour
  13.  Increase Saturation
  14.  Final Curves Tweaks

The Learning Curve

Up until this point, I’ve been the student, not the teacher.  I want to show beginners how I process my astrophotography images, but my presentation skills leave much to be desired. I have always been an artist at heart, so my methods may seem unorganized and random to the general public.  I am more likely to “trust my eyes” rather than a set of numbers and graphs, although I recognize their value.  I feel that through the process of teaching others how to capture and edit photographs of the night sky, I will gain a deeper appreciation and knowledge of the hobby for myself.  Thank you to everyone who has subscribed to my YouTube channel so far.  I am just getting started.

 

AstroBackyard on YouTube

 

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Astrophotography by Trevor Jones

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What is Astrobackyard.com?

This astrophotography blog creates an outlet for me to share images, information and tips about my favourite hobby. I received lots of help when I began this hobby in 2011, and it’s my turn to pay-it-forward to the next wave of astrophotographers. I have watched the hobby grow in the short years that I have been involved. There are more options and information out there now than ever before. The one aspect that does not change is a love for the night sky. The story behind the sites name is that the backyard is where I began my journey, and where I still spend the most time under the stars. Travelling to new locations around the continent with much darker skies is great, but happens only once or twice a year at max. My backyards is my personal window to the heavens, and it’s where I connect with the universe.

 

Lagoon Nebula by Trevor Jones

The Lagoon and Cat’s Paw Nebula by Trevor Jones

Why should I come back?

If you’re anything like me, you enjoy reading about a fellow astrophotographers experiences.  You enjoy hearing stories from someone who shares the same love for astronomy that you do.  If you use similar camera and astrophotography equipment, you might even learn a thing or two from my mistakes.  Maybe you just like to sit back and enjoy the hours of hard work I have put into each and every one of my photos.  Whichever reason you choose, I sincerely appreciate your company.

What to expect

I have recently overhauled my site to it’s current design. Astrobackyard.com is now set to become an authority in the astrophotography community.  You can expect more astronomy related news and events, more astrophotography tutorials and equipment reviews, and of course, all of my astrophotography adventures from the backyard, and beyond.  I plan to share astrophotography processing techniques that have helped me pull the absolute most detail out of my images.  Later this year I will be creating a video tutorial series on youtube that should cover the basics of my current workflow.  I am not an professional photographer, image-processor or scientist, but I am dedicated to improving my skills.  I am an active member of the Royal Astronomical Society of Canada, as the current webmaster and newsletter editor for the Niagara Centre. Please follow me on Twitter for the absolute latest news.

@astrobackyard on Instagram

I post new and old astronomy photos in Instagram quite regularly.  Feel free to connect with me over there!

 

Astrobackyard on Instagram

 

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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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