Post-production

4 Ways to Remove Airplanes from Star Stacks

When I make a star stack sequence, I’m at a crossroads for my editing choices.

Do I remove the plane trails? If so, do I live with the tiny gaps in those star trails left behind by the removal process?

It’s a hard decision. On the one hand, the journalistic approach is, “That’s what happened in front of my camera—it’s the truth.” If that’s your creed ... you’re done! Make whatever levels and color adjustments you want and move on.

But when I desire to have a final image without plane trails, I spend some time to make sure it’s done right, and that I’m making a quality photograph.

Want to learn some techniques on how to do this? Is there a method—without having to be a professional photo retoucher—that doesn’t leave gaps? Read on, my fellow night photographer.

Note:

If you are unfamiliar with how to create a star stack, see these previous blog posts:

Prep: How to Find Which Layers Have Plane Trails

I used the same image stack for all the demos below. Shot in the Fruita Orchard of Capitol Reef National Park during our workshop in June 2018.

Gear:

Exposure details:

  • 63 images shot at 30 seconds, f/5.6, ISO 6400
  • total exposure duration: 31.5 minutes

I knew I wasn’t going for star points, so I chose a 30-second exposure to keep long exposure noise down in the high desert summer heat. The temps weren’t that bad, but I wasn’t taking any chances.

For expediency, I exported full-resolution JPGs from Lightroom to Photoshop. Stacking TIFFs straight from Lightroom with this many files can really choke a computer. As it was, the PSB file was 4.2 GB when saved.

Note:

Do not apply lens profile corrections before making a star stack. It can lead to irreparable moire in the final stacked image. If you want to do apply lens corrections, do so after stacking and flattening.

How to Find the Planes

  1. Create your image stack in Photoshop and save as a PSD or PSB file (the latter when the file is over 2 GB—don’t worry, Photoshop will prompt you if it’s needed).
  2. Identify which layers have plane trails. But how, you ask?
  3. I like to turn on all the layers and apply the Lighten blend mode to each so I can see everything.
  4. Then I click and hold on the eyeball icon at left of each layer and drag downward in groups of ten or so, while staring at the image. This gives me kind of a faux animated preview of the layers being added one by one. (See video below.)
  5. If I see plane trail (or a portion of one) disappear, then I click the eyeball on each layer, one by one, upward from the bottom until it disappears. That’s how I know I found the offending layer.
  6. I make that layer a color to identify it for further work later.

An alternative way to do this is by revealing only one layer at a time, from top to bottom. Which strategy to use is just personal preference. Unless you’re on a PC, apparently. Chris is a PC user, and the trick I detail above and in the video doesn't work for him. What he does is group the layers ten or so at a time, changes the blend mode of all the groups to Lighten, then hides each group one by one, which helps him narrow down the locations of trails more quickly. Finally, he goes into the offending groups and finds the offending planes.

Either way, this process is time-consuming. So be patient. Find those planes. For the photo in the video below, the process above took me about five minutes. (I made it faster for you to watch.)

Note:

You may also find meteors and satellites in there. We have another blog post coming soon on how to identify the differences between them.

4 ways to remove plane trails in a star stack with Layer Masks

  1. Remove plane trails in a flattened image in Lightroom.
  2. Use the black paint brush in Photoshop.
  3. Use the spot healing brush in Photoshop.
  4. Use layer masks in Photoshop.

Which one is best? I am going to explore all four and compare them, so you can decide which works best for you. And, you can bet that I will have an opinion about what works best for me, too. ;-)

Removing Plane Trails in a Flattened Image

This is the fastest method, but also the least likely to be effective in terms of quality. If you must have it fast, try this first. If you don’t like the results, try one of the options that follows.

  1. Open your flattened image with plane trails in Lightroom.
  2. Select the Spot Healing Brush.
  3. Click once at the beginning of the trail. (See note below.)
  4. Hold Shift on your keyboard.
  5. Click once again at the end of the plane trail.
  6. Repeat for every plane trail on every layer.

NOTE:

You can paint freehand with the trackpad on your laptop (most awkward), with your mouse (somewhat awkward) or with a tablet like a Wacom (hardly awkward at all). This applies to subsequent techniques too.

I find that using keyboard arrow keys to move the healing brush target around is easier to manage than just using a mouse or trackpad. But it causes “jaggies” (below) more often than not, no matter how precise you are.

Using a Black Paint Brush in Photoshop

Since the Lighten blend mode for layers reveals the brightest pixels in a scene, painting with a black brush right on the image layer will make trails (which are bright) disappear.

  1. Select the Brush Tool with these settings: Opacity at 100 percent, Flow at 100 percent and Color at 100 percent black.
  2. Make your brush slightly larger than the width of your plane trail. (You may have to adjust this up and down, depending on the trail.)
  3. Paint over the plane trails. But only over the plane trails.
  4. Repeat for every plane trail on every layer.
  5. Merge layers or flatten when done with all.

Resulting image after using black brush to remove plane trails. Click to enlarge.

100 percent zoom crop to an area where a plane trail was removed.

In this video, I used the process of identifying layers first and then color-coding them before blacking out the trails. Even then, I discovered more along the way.

Note:

This is a destructive process. No going back. Unless you duplicate each layer you paint on and turn off the duplicate, but that increases your PSD/PSB size.

Using the Spot Healing Brush in Photoshop

I recently discovered this. While mucking about in Photoshop, editing my star stacks from Capitol Reef National Park earlier this year, I had a What If? moment. …

I asked myself, “What if I try using a different tool to remove star trails?” (I usually use layer masks, which we’ll get to in a little bit.)

  1. Select the Spot Healing Brush tool, and change the Type to Content-Aware.
  2. Make your brush slightly larger than the width of your plane trail.
  3. Click once at the beginning of the trail.
  4. Hold Shift on your keyboard.
  5. Click once again at the end of the plane trail.
  6. Repeat for every plane trail on every layer.
  7. Merge layers or flatten when done with all.

It works. I love this method, despite it being a destructive process.

Resulting image after using Spot Healing Brush to remove plane trails. Click to enlarge.

100 percent zoom crop to an area where a plane trail was removed.

In this video, I simply went from top to bottom to eliminate trails in each layer without color-coding them. I missed one plane trail, because I was kinda tired doing both back to back.

Note:

As mentioned, this is also a destructive process. No going back. Unless you duplicate each layer you paint on and turn off the duplicate, but that about doubles your PSD/PSB size.

Comparing the Methods

Let’s take a look at how the methods stack up against each other. (See what I did there?)

The edit in Lightroom of a completed, flattened stack? I immediately abandoned it. It was janky to complete, and undesirable:

And when your stars go the wrong way, it’s really hard to make it match:

So, all that’s left are the two competitors we’ve looked at so far. Below you can see the final images from each:

And here are some comparisons I made while viewing both simultaneously in Lightroom:

Above you can see that there isn’t really much difference between the two methods. At least in terms of image quality.

But … what did my time cost?

Painting Black

Pros: Easy to see if you covered a plane trail.

Using Spot Heal Brush

Pros: I just feel better seeing an image versus black lines all over. The trails are gone, and the layers still looks like a photograph.

Both methods have the same cons:

  • destructive to pixels
  • makes some gaps in the trails (thought remarkably few)
  • no way to go back on edits unless you duplicate your PSD/PSB beforehand

To Identify or not to Identify

I spent eight minutes identifying layers with stuff to eliminate.

I spent 30 minutes using the black brush on those layers I identified.

I spent 27 minutes using the Spot Healing Brush, layer by layer, without color-coding or pre-identifying layers.

It’s up to you which method helps you get through the process better. I can operate without color-coding in the future. One-by-one is the way for me.

Conclusion: Which Method Wins?

Guess what? Both strategies are just as effective. Yay!

And here is the proof: When gaps appear, they do so in the same places using both methods.

The above were from testing my own hypothesis that Spot Healing would work better. Surprise! I’m delighted to discover that for this test, both techniques performed the same.

Both methods create gaps. But you can meticulously fill them in with Photoshop prior to flattening. Use the clone tool, if you have the extra hours. ;-)

The Fourth Way—Using Layer Masks in Photoshop

This is how I’d always done it before my recent discovery. This method is non-destructive—if you save your PSD/PSB, you can always roll back the edits or modify them. (The downside, of course, is that an unflattened, many-layered file could be downright huge. If you’re not planning to save an unflattened file, this doesn’t provide much benefit.)

  1. Add a mask to a layer with a plane trail.
  2. Select the Paint Brush tool with these settings: Opacity at 100 percent, Flow at 100 percent and Color at 100 percent black.
  3. Make your brush slightly larger than the width of your plane trail.
  4. Click once at the beginning of the trail.
  5. Hold Shift on your keyboard.
  6. Click once again at the end of the plane trail.
  7. Repeat for every plane trail on every layer.
  8. Make your final contrast, color and other finish adjustments.

Give it a shot. You may like this better, especially if you are already masking out other things in your scene.

Et al.

Here are some examples of other stacks I’ve done using these techniques:

So go forth and capture, my fellow lovers of the night sky. And fear not the airplanes arcing across the heavens, for you can make their presence just a memory.

Matt Hill is a partner and workshop leader with National Parks at Night. See more about his photography, art, workshops and writing at MattHillArt.com. Follow Matt on Twitter Instagram Facebook.

UPCOMING WORKSHOPS FROM NATIONAL PARKS AT NIGHT

Lightroom for the Night Photographer: Learning to Master Local Adjustments (Part II)

Adobe Lightroom, the industry’s standard image editing program, is at the heart of the post-production process for most photographers. And some of the most dynamic tools in the Lightroom toolbox are the three that allow you to make local adjustments.

In my recent blog post “Lightroom for the Night Photographer: Learning to Master Local Adjustments (Part I),” I demonstrated how to use two of those tools: the Radial Filter and the Graduated Filter.

This time, in Part II, I take a deeper dive and show you how to locally edit any part of an image by wielding the Adjustment Brush. From using the brush feather and flow to employing erase, I’ll show you how get the most out of Lightroom’s most precise adjustment tool. Using multiple masks, adjustments and auto-mask, I’ll demonstrate exactly how to create natural-looking edits with precision.

Tim Cooper is a partner and workshop leader with National Parks at Night. Learn more techniques from his book The Magic of Light Painting, available from Peachpit.

UPCOMING WORKSHOPS FROM NATIONAL PARKS AT NIGHT

How Lightroom Classic CC 7.3's New Features Help the Night Photographer

Since Adobe has shifted their products from the old model of owning a piece of software to the more recent pay-per-month lease model, we have seen more frequent updates and upgrades. While many of these updates don’t make a big splash, occasionally we get a real treat. That’s the case with Adobe Lightroom’s most recent release, CC 7.3.

A particular few of these changes make life a little easier and allow some more creative options for the night photographer. We produced a video to help you navigate these changes and to learn how to maximize them for night work. We cover:

  • workflow and editing tools that have been moved to more convenient places
  • the new Adobe Color profile
  • how to use these tools to improve night imagery

Check out the following video to see what Adobe has added to our toolbox, and how night photographers can use these new and recalibrated features to craft powerful imagery!

Tim Cooper is a partner and workshop leader with National Parks at Night. Learn more techniques from his book The Magic of Light Painting, available from Peachpit.

UPCOMING WORKSHOPS FROM NATIONAL PARKS AT NIGHT

Lightroom for the Night Photographer: Learning to Master Local Adjustments (Part I)

Post-processing photographs has become an everyday affair for modern photographers. Increasing contrast, fine-tuning the exposure and correcting color balance have become as familiar to us as brushing our teeth.

Adobe Lightroom, the industry’s standard editing program, is at the heart of this editing process for most photographers. Its cataloging capabilities are incredible; its Develop module is very intuitive yet extremely powerful. Within that module, most photographers are quite comfortable working with using the sliders and other controls that make global changes to the image: from the Basic panel’s Exposure, Contrast, Highlights sliders, et al., right down through Tone Curve, Detail and Lens Corrections panels, et al.

But many photographers don’t have quite the same level of comfort with the local adjustments—those tools remain a mystery.

So, what exactly is a local adjustment? Well, a local adjustment is when you are effecting a change to only a specific portion of a photograph. A global adjustment, on the other hand, affects the entire image.

In the following video, I’ll demystify Adobe’s two local adjustment tools—the Graduated Filter and Radial Filter—and show you how can use them to tightly control the look of your night photographs.

Tim Cooper is a partner and workshop leader with National Parks at Night. Learn more techniques from his book The Magic of Light Painting, available from Peachpit.

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Dehaze: The Night Photographer's Secret Weapon

Did you know that Lightroom has a secret weapon for night photographers to make the Milky Way look fantastic? It’s way down toward the bottom of the Develop module: the Dehaze tool. In this post and in the video at the end, we’ll show you what this great tool was originally designed to do, plus how to use it to make stars sizzle!

The Dehaze slider was introduced in 2015 shortly after Adobe’s upgrades to their new cloud-based pricing structure. So, if you are still using an older standalone program (Lightroom 4/5/6) but want to take advantage of this awesome tool, then it’s time to update to Creative Cloud.

So what exactly is Dehaze? An official description from Adobe states, “Dehaze is a feature for removing haze/fog from pictures. It is based on a physical model that tries to estimate the amount of light transmission and how it varies across the picture. The user can then control how much haze to remove by adjusting a slider.”

Perhaps a less confusing way to think about it: Dehaze adds more contrast.

However, Dehaze is not like the Contrast slider. It adds contrast in a different way. A smarter way. The Contrast slider adds contrast mostly to the midtones and its affect tapers off in the highlights and the shadows. The Dehaze slider functions by targeting the lower-contrast areas of the scene and applying the bulk of its effect there. This means low-contrast areas of the scene get more of the effect than the higher-contrast areas of the scene. Brilliant! This is just what we need.

To apply the Dehaze filter, open an image, head to the Develop module and simply scroll down to the Effects panel. You’ll find the Dehaze slider at the bottom. Moving it to the right increases contrast, moving it the left decreases contrast.

Figure 1.

Figure 2 below shows a typical use of the Dehaze slider. Notice how moving the slider increases the contrast in the sky and mountains (which were lower-contrast to begin with) much more than it does in the flowers in the foreground (which were already higher-contrast).

Figure 2.

But, here’s some great news: The Dehaze slider works for more than just haze. Figure 3 shows how it can enhance a waterfall and the rainbow in its mist. Once again, notice the increase in the brighter and lower-contrast area of the scene. It’s receiving much more of the effect than the foreground hillside.

Figure 3.

Care should be taken with this slider, though. In addition to increasing contrast, it also increases saturation, especially in the blues. Too much of an increase can produce an overly saturated, false-looking image. Figure 4 shows how the blue tones increase in saturation when the Dehaze slider is cranked up.

Figure 4.

So how does all of this apply to night photography? Well, increasing contrast and saturation is precisely the way we emphasize our night skies and Milky Way! Figure 5 shows the before image of the Milky Way over Mount Reynolds in Glacier National Park and the same image after increasing the Dehaze slider to +67. Notice how the dimmer stars become more pronounced and the Milky Way seems to become more three-dimensional.

Figure 5.

For a more complete description and more examples of how the Dehaze slider can improve your night photos, check out our 13-minute video below:

The next time you want to intensify and emphasize your night skies, visit the Effects panel in Lightroom and increase the Dehaze slider. Just remember: Kid gloves—use a light touch. A little goes a long way.

Note: For a comprehensive tutorial on Lightroom’s Library and Develop Module, check out Tim’s 33-part, six-plus-hour video on Vimeo.

Tim Cooper is a partner and workshop leader with National Parks at Night. Learn more techniques from his book The Magic of Light Painting, available from Peachpit.

UPCOMING WORKSHOPS FROM NATIONAL PARKS AT NIGHT