Backyard Astrophotography, Part 4: Post-Processing

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Welcome to Part 4 of my guide to Basic Backyard Astrophotography. If you missed Part 1, Part 2, or Part 3, please click these links, and we will see you back on this page in a few minutes. In this segment, I share how I post-process some of my astrophotos. As you are about to see, processing astrophotography images is fairly basic and, in my world, is as much about art as it is about science, with a lot of experimenting sprinkled in.

Photographs © Todd Vorenkamp

Mars (left), Saturn, the Milky Way, a lighthouse, and a few people who stood in the right place at the right time.

Post Process

Just like the fact that there is no universal exposure for capturing portions of the night sky, there is no fixed and firm recipe for how to post-process astrophotography images. I will show you what works for me on some images, but it may not work for other photos. The cool part about post-processing astro images is that it is really up to you, the photographer, to play with the sliders in your post-processing software and make the image look like you want it to look. Your “model” is the heavens, but you are the artist who gets to interpret what it looks like on your screen or in a print! (Even NASA does a lot of false-color processing of its astro images to illustrate different aspects of celestial phenomenon.)

The Milky Way

So, here is a KISS (Keep It Simple, Stupid) rundown of ideas for sliders inside Lightroom, from top to bottom, when processing starscapes (the moon or planets will be different).

  1. White Balance I don’t have much luck neutralizing astro images with the eyedropper. Try “Auto,” leave “As Shot,” or try “Daylight” (some stars are just like our sun, right?) and then move the sliders around. Be careful, a little slider goes a long way.
  1. Exposure If you followed my advice and did ETTR, you will be dialing back the exposure slider toward the negative range. Depending on the image, you might be doing two or three stops of exposure reduction in post.
  1. Contrast I usually dial it up a bit.
  1. Highlights Mostly I go +100 here, but sometimes I dial it back.
  1. Shadows Ditto on Highlights. Try +100 and adjust if needed.
  1. Whites Where this slider ends up is totally dependent on the image. Sometimes it stays at 0. Sometimes it goes right, other times it goes left.
  1. Blacks Same as Whites. No rhyme or reason here, either.
  1. Clarity 90% of the time I set it to 100 and leave it.
  1. Dehaze (This could be lower depending on what version of LR you are using.) A little goes a long way. I usually add in about 10-20.
  1. Vibrance Season to taste.
  1. Saturation I like to make things pop by dialing it up, but not too much!
  1. Sharpening The more you add, the sharper the stars… and the noisier the noise. Use in moderation. Hopefully, your lens gives you good sharpness out of the box.
  1. Noise Reduction You can watch thousands of hours of YouTube videos or spend hundreds on noise reduction LR add-ons, but I just move the sliders a bit until it looks good or better. KISS.

Believe it or not, that about covers it from capture to saving as your newest computer screen wallpaper. Not only is it easy, it’s fun and every time I go out shooting the stars, I come back with images that I really love to process, admire, and share.

What is the easiest way to fit over a billion stars in one photograph? Point your camera at the Andromeda galaxy. Andromeda is the closest galaxy to the Milky Way and the only galaxy that you can see with the naked eye (usually only in a dark sky area). Here is Andromeda captured with the Fujifilm X-T2 and 23mm, 35mm (two images, with and without the constellation Cassiopeia), and 105mm lenses (equivalent of 35mm, 50mm, and 160mm lenses), proving that you can do deep-sky photography without a tracking mount.

Expand Your Gear

Many photographers have proven that you don’t need a mega-megapixel camera or the world’s most exotic optics to make captivating images of the night sky. That is the good news for those of you with entry-level DSLRs, mirrorless cameras, and kit lenses. But, say you just read the above information and went outside and made your first awesome astrophoto (Please tell me about it in the comments if you want!) and you want to know what gear or tools can improve your future astro images. For those cases, here is a short list.

  1. Prime Lenses As good as today’s kit zoom lenses are, nothing compares to the light-gathering capabilities of a high-quality prime lens. Note that “high-quality” need not mean “high price.” I will always be a fan of the ubiquitous 50mm lens (approximately 35mm for APS-C shooters) and, with the f/1.8 options on the market, you will not find a better value in a super-wide-aperture optic that is perfect for capturing details in the night skies above. Some of these wide-aperture primes are even less expensive than your kit zoom—and optically superior. Get one!
  1. Focal Length Speaking of lenses, always consider the focal length. The wider you go, the more sky you capture and the longer shutter speeds you can use to gobble up more light (remember the Rule of 500). But, if you want to look more closely at a planet or nebula, you will need lenses on the telephoto end of the spectrum. The downside here is that shutter speeds need to be very short. You can do a 21-second exposure with a 24mm lens, but a 200mm lens on a full-frame camera needs a shutter speed faster than 2.5 seconds—that isn’t enough time to let a lot of starlight in, and that leads me to the next item…
  1. Motorized Tracking Mount I did not own an equatorial camera tracking system until the run-up to the 2017 total solar eclipse, and I often wake up in a cold sweat thinking of how I should have bought one 20 years ago. If you have been bitten by the astrophotography bug, a tracking mount is—no understatement here—a game changer. With the tracking mount, I still shoot ETTR exposures, but now I can shoot a 200mm or 300mm lens for 30 seconds or more with no star movement in the frame. It opens a lot of new astro-imaging possibilities. As cameras’ high ISO performance gets better and better, there will be a day when the tracking mount will be superfluous for some images, but that day is not here yet, so bide your time with your own tracking mount.

With the addition of a tracking mount, a huge number of celestial objects can be photographed by your camera. Here we have the Andromeda galaxy, the Lagoon and Trifid Nebulae, Saturn, the Omega and Eagle Nebulae, and more.

Other Resources

There is a veritable ton of Internet and published resources on astrophotography. Since the dawn of the digital camera, this segment of the art of photography has become accessible to almost everyone with a digital camera, and there are a lot of astrophotographers like B&H Photo affiliate Ian Norman of www.lonelyspeck.com, who have poured their hearts and souls, and buckets of knowledge into their über-informative websites, to tell the rest of us how to be successful astrophotographers. This short article is just another one of my contributions to the vast Internet library of how-tos when it comes to astrophotos.

Now it is time for one of two things: 1) You can most certainly post comments, ask questions, or share your tips below or, 2) Is it dark and cloudless outside? Go take some photos of the heavens!

Astrophotography and astronomy can be a social event. Find the nearest observatory and see if they have star parties. My local observatory will bring hundreds of stargazers out on a given Friday night.

Additional Resources

The best Milky Way Photography website: www.lonelyspeck.com

How to Set Up Your Camera for Night Photography: https://www.bhphotovideo.com/explora/photography/tips-and-solutions/how-set-your-camera-night-photography

B&H Photo Podcast with Lonely Speck’s Ian Norman: https://www.bhphotovideo.com/explora/photography/features/podcast-shooting-stars-part-ii-deep-sky-diy

12 Comments

Nice series of articles on Astrophotography.  I'm ready to give it a try.  Got to ask though, what adapter do you use to attack Nikkor lenses to your X-T2?  Thanks.

Hi William,

My answer: I use a Novoflex adapter. https://www.bhphotovideo.com/c/product/888375-REG/Novoflex_fux_nik_Adapter_for_Nikon_Lenses.html

Here is the short version of a long story...

You might have noticed that that Novoflex adapter is expensive. (I actually got one for less from our Used Department.) I thought it was prohibitively expensive as well, so I bought an adapter from another reputable adapter company. It did not work well as far as infinity focusing and the feel wasn't good. I thought I had gotten a bad copy, so I returned it and had the same issues. Done with my cost-saving experiment, I went with the Novoflex and haven't looked back.

Having said that, I recently tried the Vello Pentax to Fujifilm X mount and it seemed to work well and was very tight.

Not knowing your budget, you could start with an inexpensive one and see if it works, but, if it doesn't, hopefully you can get some B&H Gift Cards for your birthday and get the Novoflex.

Good luck and let me know if you have any follow-up questions!

PS. If you have any Nikon G lenses (no aperture ring), you'll need an adapter with the aperture control ring or you will be shooting your adapted lenses wide-open all the time.

I appreciate the quick response Todd.  And you're right, a new one is not cheap!  Unfortunately B&H didn't have the model I needed in the used department.  And eBay (not my favorite) only had the cheap ones you referred to.  I'll keep looking.  Thanks for the follow up.

Hey William,

You are welcome! No worries! Keep an eye out for the Novoflex in the Used Department, and maybe try a less-expensive one until one becomes available? We do have a 30-day return policy, if that helps (I used it twice on my adapter journey!).

Good luck!

Great article, thanks!  I was wondering what post production software you use?

Hi Bridges,

Thank you for the kind words!

I am a Lightroom/Photoshop user.

I might be trying some add-on or stand-alone stacking and noise reduction software in the future, but I currently just live in the world that Adobe has carved out for me.

Thanks for reading!

Todd,

Thanks for all the great advice.  I have enjoyed photographing the 2017 total solar eclipse and the recent lunar eclipse, and plan to try some shots of the Milky Way next.  I would like to add one bit of advice regarding focus.  Some zoom lenses (including mine) do not hold focus when the zoom is changed.  Because of this, I can't go to maximum zoom to manually focus, and then pull back out for the shot as you suggest.  For best focus, I have to set the zoom first, and then focus.  I suspect this will be the case for many kit and mid-level lenses.  As a work-around for this problem, I use the digital "focus magnifier" function in my camera for closer view while focusing.  As you mentioned, using focus peaking in the display is also very helpful.  Thanks again for a great series of articles.

Hi Philip,

You are welcome!

Great point regarding focus! I may change the text for clarity.

By the way, the term for a lens that remains in focus when being zoomed in or out is "parafocal."

Thanks for reading Explora!

Hi Todd,

While not new to photography, I'm new to astrophotos.  I've used a lot of the skills and techniques in post processing to apply to this world.  I was incredibly relieved to see that your approach to post processing is much like mine.  I was fumbling through it, not sure if I was doing it right.  Thanks for the boost in confidence.  Now I need to get busy planning my next adventure into the dark skies of west Texas.  Thanks a bunch.  

Hi Michael,

Thanks for the kind words. I am sure there are some astrophotography veterans that might scoff at my methods, but I want to keep things simple for the reader (and myself) and get on with making and sharing photos!

Thanks for stopping by!

Thank you Mr Vorenkamp. I am a long time lover of night shots, but newer to the astrophotography class. (I like shooting cityscapes with light trails from vehicles.) I, like mahy, was hit with the bug with the latest solar eclipse. I took some shots and some turned out, others not so well. BUT, I will keep trying. Thank you for your knowledge and I will try to get the shot that all have been trying to get in their portfolio.

Hi Rick,

Call me "Todd!" I like to pretend that I am still young! :)

Thanks for the kind words! I hope this series of articles is helpful to you. There are some great tutorials on the web, but I have tried to craft this series for those just starting out in astrophotography.

For the next solar eclipse, check out the lessons I learned at last year's... https://www.bhphotovideo.com/explora/photography/tips-and-solutions/8-lessons-learned-when-i-photographed-total-solar-eclipse

Keep shooting at night! Cheers!

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