Processing Star Point Images with the Help of Starry Landscape Stacker

We all love shooting under the stars, but oftentimes we are pushing our cameras and lenses to the extreme. In last month’s article we talked about “Shooting for the Sharpest Stars” and how that forces us into even higher ISOs and shorter exposures. Most cameras have difficulty at 6400-plus ISOs, and the shorter exposures make it tricky to get any detail in the foreground.

Enter the Mac-only software Starry Landscape Stacker (SLS), which blends multiple high ISO star point shots to reduce noise while keeping your stars sharp! (For PC users, your solution is Sequator, which operates and yields similar results to SLS. We will take a closer look at Sequator on our blog a little later this year.)

What is Starry Landscape Stacker?

SLS is a very intuitive piece of software that gives you smoother final images by recognizing and aligning the “tracked stars,” and then stacking the files while applying noise reduction to the other areas of the sky. This is probably the best piece of software to squeeze the most image quality out of multiple files instead of just working with one.

In this post, we’re going to look at the basics of how to use SLS. At the end, you can watch a video of me working through the details of processing an image this way.

Shooting Considerations for SLS

The key for both SLS and Sequator is that we shoot multiple images in the field—at least 10, but 20 is even better. The more information the program has, the better it will work.

So, once you settle on your star point composition, check focus and attain a good exposure, don’t just take one or two shots and move on. Instead, set your intervalometer to take 20 shots with a 1-second interval between. And you can certainly take more than 20 shots. If I have settled on a really nice composition, I might shoot it for an hour or so to get different alignments of the Milky Way as it moves across the sky.

We also have to consider the foreground. In the Figure 1 below, the exposure is good for the sky, but there’s hardly any information in the foreground.

Figure 1. Nikon D5 with an Irix 15mm f/2.4 lens. 25 seconds, f/2.5, ISO 6400.

How can we fix it? Three solutions:

1. Take a twilight shot.

If you arrive to your location prior to nightfall, take a few shots as the light varies throughout the twilights. You can use those later to blend into your star shot. Of course this approach works for only one setup per night (unless you have two or more cameras), but it can create a unique look. (In previous blog posts you can see examples of when Matt and Tim have done this.)

2. Light paint your foreground.

This works really well if we have something dominant in the foreground that is easily reachable with our light painting tools. However, if we have a big swathe of landscape, that will be difficult to paint.

3. Take a longer foreground-only exposure.

Lower your ISO, turn on your long-exposure noise reduction, and take a shot that is three to six stops higher than your sky shot. By using the a lower ISO we can get a cleaner foreground. But don’t expose so that it looks like a daytime foreground—my rule of thumb is to shoot a foreground exposure that gets the histogram off the left side and more in the middle (Figure 2).

Figure 2. Nikon D5 with an Irix 15mm f/2.4 lens. 13 minutes, f/2.5, ISO 1600.

My thought process on for this image: It was very dark, with no moon in the sky in Capitol Reef National Park, which is a Gold Tier Dark Sky Park. I figured an exposure of 4 minutes at ISO 6400 (three stops brighter than the sky shot) would start to reveal foreground. However, I also didn’t want the 6400 noise in the darker foreground, so I lowered my ISO two stops to 1600, which is incredibly clean on the Nikon D5. Adding five stops to my original image gave me an exposure of 13 minutes (should have been 16 minutes, but oh well), f/2.5, ISO 1600.

Don’t look at how bright the sky and the trailing stars are—the piece we want from this image is the foreground detail of the road cutting through the landscape.

Preparing Your Files for SLS

There are a few key things to do to your sky files in either Lightroom or Camera Raw to best prepare them for SLS. The idea here is to remove any chromatic aberrations and have a nice flat file that will help SLS align and combine the dimmer stars.

1. Lower the contrast of the image. I generally set my contrast to -100 and increase the exposure to +.30 (Figure 3). It won’t look good on the screen but that’s OK—just be careful you are not blowing out any stars.

Figure 3.

2. Turn off any sharpening and noise reduction. Bring the sliders all the way to zero (Figure 4). SLS will handle the noise reduction for now and we will do the sharpening after SLS stacks the image.

Figure 4.

3. Correct for lens aberrations. Under the Lens Correction section of Lightroom, check Remove Chromatic Aberration (Figure 5) and manually adjust any vignetting to even out the exposure of the image (Figure 6). I choose to manually adjust the vignetting instead of turning on “Enable Profile Correction” (EPC) because I’ve noticed weird artifacts/moire patterns in the stacked images when doing so early in this process. EPC adjusts for distortion and vignetting, so it’s best practice to apply the Lightroom adjustment (if you want) to the finished image after stacking in SLS. Again, our goal here is only to prepare a nice flat file that SLS can use to easily recognize the stars, sky and landscape for blending. Minimum pre-processing equals maximum results.

Figure 5.

Figure 6.

That’s it! You don’t have to remove airplane trails or satellites. SLS will help you remove them from or add them into the final image.

Once you have worked on the first image of your “batch” you can then quickly sync the adjustments to other files. Choose your best 10 to 20 consecutive images that have the best positioning of the Milky Way or stars, and export them as full-resolution 16-bit TIFF files that include all metadata (because SLS uses your exposure information when stacking). (Figure 7.)

Figure 7.

Processing in SLS

I’ll go into more in depth in the video below, but here are some overall processing tips:

1. Open the files in SLS. It will stack them together and there will be a bunch of red dots that identify the stars.

Figure 8.

2. Follow the “Workflow” instructions at the top left.

3. Adjust Dots in the Sky. Remove any red dots on the ground, along the horizon, in cloudy areas, or in any spots where there weren’t actually stars. You can even add dots into the sky if there are major areas in the sky that don’t have them.

4. Click Find Sky. That will create the blue mask of the sky; it doesn’t need to be perfect but should include all the areas where there are stars. If you have a horizon that has lots of trees cutting into the sky, choose “Mask with Islands of Sky” and that will let SLS know to create masks for the stars between the branches. You might need to clean this up, but SLS does an excellent job to get you started.

5. Align With. This will remove the blue mask. At the bottom of the workflow section it says Current Image. Click on Next and Previous to choose which Milky Way/star-point alignment you’d like SLS align to.

6. Align and Composite. This stacks all the images. You have to select a composition algorithm to choose:

  • Min Horizon Noise is the default and works in most cases. It brightens the Milky Way stars a bit more than the surrounding stars and minimizes the noise along the horizon.

  • If you do notice any star trailing or duplication along the edge of the mask, use the Min Horizon Star Dupe. There is also a “mean” version of the Horizon Noise and Star Dupe—this uses the older “median” algorithm that was seen in previous versions of SLS.

7. Click Save. SLS saves the stacked file to your folder of TIFFs. SLS gives you the option to save a copy of the mask; I generally don’t need it as the masked file works fine. You’ll need to import this new file into LR and then do any image massaging there.

Tip: You can save multiple algorithms of the stack. The Max algorithm reveals any airplanes, satellites or meteors. Save a clean Min Horizon Noise for minimal noise, but then save any meteors that came through and you can blend them together in Photoshop!

Walking Through an SSL Edit

That’s it! You now have the cleanest night skies out there! Check out the video below, where I go into detail and walk through the whole process. I also take the SLS night sky image and blend it with the foreground from the longer exposure in Photoshop.

Milky Way season is here and the temperatures are rising, bringing more noise into our shots. Use Starry Landscape Stacker to create even cleaner jaw dropping night images!

Gabriel Biderman is a partner and workshop leader with National Parks at Night. He is a Brooklyn-based fine art and travel photographer, and author of Night Photography: From Snapshots to Great Shots (Peachpit, 2014). During the daytime hours you'll often find Gabe at one of many photo events around the world working for B&H Photo’s road marketing team. See his portfolio and workshop lineup at www.ruinism.com.

How I Got the Shot: Light Painting and Star Trails at Devils Tower

Stars at Devils Tower. Nikon D750 with a Zeiss 15mm Distagon f/2.8 lens. Ten stacked frames, each shot at 150 seconds, f/2.8, ISO 1600 (1,500 seconds total).

The Conditions

Shooting under moonless conditions can create consistent challenges for astro-landscape photography. The primary challenge is lighting your main subject. When it’s the Devils Tower in Wyoming, you’ve gotta get it right.

Gabe and I were leading a group of eager learners on a workshop a few years ago when I made the above image.

I was not standing at my camera—I was up at the base of the Tower, illuminating it.

So how did we do this?

The Shoot

Well, lemme first show you how it looks without being lit, which you can see in Figure 1.

Figure 1. Nikon D750 with a Zeiss 15mm Distagon f/2.8 lens. 150 seconds, f/2.8, ISO 1600.

It lacked the detail that screams, “Is that the mountain from that famous movie?!?” Right? Yeah.

But one frame did stand out: when some climbers who had to descend after dark illuminated the deep crevices that are the hallmark of this natural stone edifice (Figure 2).

Figure 2. Nikon D750 with a Zeiss 15mm Distagon f/2.8 lens. 30 seconds, f/2.8, ISO 6400.

Aside from that, we wanted more detail in the Tower. So I set my intervalometer to take many, many (infinite, in fact) exposures. (You can read more on how to do that in our post “Mastering the Intervalometer for Night Photography and Long Exposures.”

I knew I intended to make an epic star trail from this. So I aimed for longer exposure lengths of 150 seconds and let the sequence begin. I knew this was still short enough to manage the long exposure noise that the camera would generate in the mid-August Wyoming heat.

I grabbed a two-way radio and drove up to the parking lot. I hit the loop trail and started doing my own lighting. From so far away from the camera, how did I know I was executing the light painting sufficiently? That’s where the radio came in—I kept pinging Gabe to see if my flashlight was providing proper detail and coverage. Trusting Gabe to be the lighting director from the camera position was crucial.

Gabe advised me to cover about one-quarter of the arc around the base of the Tower. We tried a few variations and settled on a final strategy (Figure 3).

Before and after light painting from the base of the tower.

I shot many different variations (Figure 4) through the evening, sometimes re-framing, sometimes adjusting the exposure length. Even when you’re confident about your approach in the field, it’s always good to push the boundaries of your decisions and to give yourself more options to look at when back at the computer.

Figure 4. The different strategies I shot that night gave me lots of options to choose from in post.

The Post-Production

The final set of frames I chose to work with is this:

Figure 5.

Each image required a gradient for the sky, and a proper Range Mask set to 28/100 Luminance and 19 Smoothness. I also used the mask brush to remove the gradient from Devils Tower itself and from the trees below.

Once the mask was done, I made the adjustments, which were intended to emphasize (but not over-process) the sky. Sometimes that’s a fine line, and one we always want to be conscious of. You can see the mask I created in Figure 6, and the adjustments in Figure 7.

Figure 6.

Figure 7.

Then I needed to stack the frames in Photoshop. In several previous How I Got the Shot blog posts we’ve discussed stacking frames to create star trails and to combine different light-painted compositional elements into one image. This time I used the same technique to achieve both those goals in one photograph—i.e., to get the stars to trail and the light-painted sections of the Tower to composite.

The process is:

  1. Select all the pertinent frames in Lightroom by shift-clicking the first and last.

  2. From the menu, choose Photo > Edit In > Open as Layers in Photoshop.

  3. Once the image opens select all the layers by clicking on the top layer, pressing the shift key and then clicking on the bottom layer.

  4. In the Blending Mode dropdown above the layers (the box that defaults to saying Normal), choose Lighten.

  5. Save and close, which will bring the stacked image back into Lightroom where you can make final edits.

I was really pleased with the stacked result:

Nikon D750 with a Zeiss 15mm Distagon f/2.8 lens. Ten stacked frames, each shot at 150 seconds, f/2.8, ISO 1600 (1,500 seconds total).

The photograph has more mystery with the tree line falling into silhouette and the Tower having detail. This emphasizes where the viewer should look.

A Little Cleanup

Due to some people’s red headlamps and flashlights, the trees and ground closest to us picked up the color. It’s quite hard to edit away, so I brushed in some local adjustments subtracting highlights and whites. After stacking, that still wasn’t enough, so I ended up using layer masks to eliminate the distracting details.

(Hmmmm. Come to think of it, it may have been the brake lights of my rental car when I returned to the group. D’oh! And possibly a “mea culpa” moment. Whoops. Bad Matt.)

When I re-edited the stack this time, I noticed something new. I wanted to crop it to a vertical. It felt … more powerful. More focused.

The final, final result:

Nikon D750 with a Zeiss 15mm Distagon f/2.8 lens. Ten stacked frames, each shot at 150 seconds, f/2.8, ISO 1600 (1,500 seconds total).

Wrapping Up

I gotta say, I am excited to return to the Devil’s Tower with Chris later this year. It’s going to be amazing. What will he and I dream up together? And what will the workshop participants dream up? I bet it’ll be out of this world. (Yeah, I went there.)

How do you achieve better astro-landscape photography by collaborating with friends and peers? Tell us more in the comments, and show us photos!

Note: Want to join Matt and Chris to make epic night photography images at Devils Tower National Monument? We have two spots left for the workshop, so sign up now!

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.

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The Color of Night: The Proliferation of LEDs and its Effects on How We Photograph

If you’ve been paying attention, you may have noticed that it’s gotten much cooler at night in recent years––about 3000 degrees cooler!

The nighttime world has transitioned from one that was overwhelmingly lit by yellow-orange sodium vapor lamps to one lit primarily by daylight-balanced LEDs. It’s happened quickly and it’s had a huge impact on night photography, especially in urban areas. Even night photography in national parks is impacted, as the distant glow on the horizon shifts from orange to white.

While there’s no doubt that LED lighting is more energy-efficient, and generally easier on the eyes, it is making for much more mundane and ordinary-looking night photographs.

Figure 1. Trona Pinnacles, California. November 2014. Canon 5D Mark II with a Nikon PC Nikkor 28mm f/3.5 lens. 30 seconds, f/8, ISO 6400. White balance: tungsten. Foreground lighting with a Four Sevens Quark 123 LED flashlight. Sky glow from mostly sodium vapor lights in the nearby small city of Ridgecrest.

Back in the 1990s I was living in San Francisco, and much of my night photography was done in and around industrial sites in the Bay Area. My friend Tom Paiva and I explored the abandoned piers along the Third Street corridor in the south of San Francisco, and the Southern Pacific rail yards across the Bay Bridge in Oakland. We were drawn to the strange machinery and architecture of these sites, but most of all it was the odd mixture of high and low pressure sodium vapor, mercury vapor and metal halide lights that we found so irresistible. We sought scenes lit with multiple light sources that created surreal colors when combined with long exposures on our film (Figure 2). These were exactly the kind of situations that I tried hard to avoid or to correct for in my commercial architectural work.

And there’s the rub––mixed lighting can be both a curse and a blessing depending on the situation at hand. To the artist, it makes for worlds of possibilities, and to the commercial photographer concerned with color accuracy, nothing but headaches.

Figure 2. Petaluma, circa 1994. Shot on Fuji NPL color negative film (tungsten), exposure unrecorded. A combination of sodium and mercury vapor lights illuminates separate parts of this image making for areas with radically different color balances—not to mention that crazy purple sky. Note the light on either side of the pole in the foreground.

Photographing mixed-lighting scenes with digital cameras and adjusting the white balance in post-processing allows for great flexibility in how an image is presented, and in turn the feelings or moods it elicits. We have it easy today being able to fine-tune (or even dramatically shift) the white balance after an image is made, and local adjustments make it even easier to “correct” for different colored light sources in the same frame.

Not too long ago that would have been an unimaginable luxury. Back in the days of 4x5 transparency film, I shot assignments where I would have to make multiple exposures on the same sheet of film for each light source. Testing was required to find the right filtration to put in front of the lens for fluorescent, incandescent, sodium, halide and other light sources, and if daylight was involved, windows would often have to be blacked out and then exposed for separately with all of the other light sources turned off. All of this had to be done while making sure the camera didn’t move between exposures. The gas discharge lamps often took 5 to 10 minutes to warm up after being turned off, so testing and exposing Polaroids and film might have taken 2 or 3 hours for a single image. In some instances, I could filter the lights directly and make a single exposure, but putting filter sleeves on a sea of fluorescent tubes in a large office space wasn’t much fun either. This is what it was like in the days before digital photography and even Photoshop.

But, back to our future …

In the images below of an old textile mill in Pawtucket, Rhode Island, the overall scene is lit with high pressure sodium vapor lights, and there’s a metal halide light out of sight behind the building on the right side of the frame. The interior is lit with either incandescent or possibly more sodium vapor lights.

In each version, I’ve set the white balance differently by using Lightroom’s eyedropper tool to click on an area lit by one of the light sources. As is usually the case, my preferred white balance is somewhere between the neutral points used in the first two examples. After using the eyedropper tool to check various white balances (Figures 3a and 3b), I pick the one that is closest to what I want and then use the temperature and tint sliders to further refine the color (Figure 3c). In this kind of situation, the “right” white balance is the one that looks best, not a perfectly neutral setting.

Figure 3a: Pawtucket Textile Mill. December 2015. Nikon D750 with a Nikon PC Nikkor 28mm f/3.5 lens. 10 seconds, f/8, ISO 400. White balance neutralizing the metal halide light: 3100 K, +15 Magenta.

Figure 3b: The same image with the white balance neutralizing the sodium vapor light: 2050 K, +4 Magenta.

Figure 3c: The same image with the white balance set to personal taste: 2450 K, +7 Magenta.

Figure 4: An LED streetlight casting multiple shadows in Los Angeles, December 2013.

LEDs in the Modern World

In my recent travels, I’ve noticed that in both large cities and small towns around the country, most places have almost fully transitioned to LED lighting within the last 2 or 3 years. Lighting technology has evolved quickly, and early adapters—such as the city of Los Angeles (Figure 4), which converted to LED in 2012 and 2013—now find themselves with outdated fixtures that use multiple diodes and cast weird repeating shadows. Newer lights are brighter, and don’t require multiple diodes for adequate brightness. Even my tiny hometown of Hinesburg, Vermont, has completely transitioned to LED streetlights, casting the town in a naturalistic—but boring—neutral glow.

I had the great fortune to lead National Parks at Night’s Easter Island and Morocco photo tours this winter, and observed that relatively poor and extremely remote Easter Island (Figure 6) has converted to LED lighting, but Morocco, which generally has better infrastructure, is still lit mostly by sodium vapor. Granted, there’s only one town on Easter Island, while Morocco (Figure 5) is a country that is slightly larger than California with several major cities! I guess it’s not a fair comparison, but it was interesting to see. I haven’t been to Cuba since 2015, but I’m guessing that when Gabe returns next week, he’ll report that Havana still glows orange at night!

Figure 5. Essaouira, Morocco. March 2019. Nikon D750 with a Nikon PC Nikkor 28mm f/3.5 lens. 13 seconds, f/11, ISO 100. White balance was set to auto, which used 4350 K, +36 Magenta. I adjusted it to 3950 K, +37 Magenta by clicking the eyedropper tool just above the archway in the foreground. The orange light is high pressure sodium vapor, the green is from mercury vapor, and the archway was lit by either metal halide or LED. The window in the tower is most likely an LED bulb.

Have you noticed the Color of Night in your town lately? Has it changed, and if so, was it for better or worse? Let us know in the comments below or on our Facebook page.

Figure 6: Tahai, Rapa Nui. February 2019. Nikon D750 with a Sigma 24mm f/1.4 lens. 20 seconds, f/2.2, ISO 3200. White balance was set to auto, recorded as 3550 K, +2 Magenta, and adjusted to 3300 K, +6 Magenta. Six vertical images, merged to panorama in Adobe Lightroom. The Moai at Tahai are just at the edge of Hanga Roa, the only town on Rapa Nui, or Easter Island. They are the only Moai that are (indirectly) lit by artificial light, and one of them told me that they were not pleased at being lit up all night every night. Most of the light in this scene is from LED street lighting, but there is one sodium light casting a yellow tinge on the right side of the image. The rock platform in the foreground on the left was lit with a Luxli Viola set at 3200 K.

Lance Keimig is a partner and workshop leader with National Parks at Night. He has been photographing at night for 30 years, and is the author of Night Photography and Light Painting: Finding Your Way in the Dark (Focal Press, 2015). Learn more about his images and workshops at www.thenightskye.com.

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New Rule for Shooting the Sharpest Stars in the Sky

Kareem (@wildnkrazykid) searching for the sharpest stars in the sky. Nikon Z 6 with Irix 15mm f/2.4 lens. 20 seconds, f/2.4, ISO 16,000.

In this golden age of night photography that we live in, the quest for the sharpest stars seems to be the most elusive. But it’s certainly an achievable goal, and we’re here to help you reach it — to reach for the stars, you might say.

Sharp stars can mean two things: Focus and proper exposure. We discussed the multiple ways you can master focus in Chris Nicholson’s article “Staying Sharp.” Today we are going to take a deep dive into working out the best exposure for your camera and lens combination to create tack-sharp stars that don’t trail.

The 600/500/400/250/200 Rules

When I first started shooting digital night photography a decade ago, we used a simple rule to figure out the best shutter speed for star point photography. That was the 600 Rule. Divide 600 by the focal length of your lens, and the result was your maximum shutter speed for achieving pinpoint stars. For example:

600 / 20mm lens = 30 seconds.

This seemed to work fine, but for those of us who were making prints bigger than 8.5x11 inches, we were noticing that those stars weren’t as round as they should be. In reality, they were tiny lines.

So we adapted the rule to 500:

500 / 20mm = 25 seconds

The 500 Rule became the standard for many night photographers and worked fairly well with larger prints and cameras under 20 megapixels. However, as cameras increased the millions of pixels they put into their sensors and with the variety of different size sensors, we needed to adapt again. Over the last 4 to 5 years we have been using the 400 Rule for full-frame cameras under 30 megapixels, the 250 Rule for APS-C sensors and the 200 Rule for Micro Four Thirds. (For an explanation of why this all works, see Lance’s two-part blog post “What’s the Longest Usable Shutter Speed for Astro-landscape?”)

400 / 20mm = 20 seconds

250 / 20mm  = 12.5 seconds

200 / 20mm = 10 seconds

These results were more accurate than the previous 500/600 rules and were customized to our sensor sizes. However, if you were to zoom in to 100 percent, or get close to a large print, you would definitely still see slight movement in those luminous points in the sky.

Add to the equation that higher-megapixel cameras (40-plus megapixels) were actually doing a decent job at higher ISOs, which meant our images were showing more detail than ever before. More detail means that trailing stars become more noticeable.

Not to mention that those “rules” are just guidelines to get you in the right ballpark for shutter speed. Other factors affect how quickly stars begin to trail, including declination (i.e., your place on the globe) and which compass horizon you’re facing. The point is (see what I did there? point?), if you want to be precise about getting sharp star points, there’s a lot that goes into figuring that out.

A Modern Solution for a Modern Problem

A couple of years ago, Frédéric Michaud—a French photographer and amateur astronomer—devised the ultimate formula for the Astronomical Society of Le Havre. That formula is called the NPF Rule. Don’t bother trying to decipher the acronym; the letters aren’t initials, they’re variables:

N = aperture
P = pixel pitch
F = focal length

I’ll be honest—the formula is a bit complex. Besides the focal length of your lens, it also takes into account the camera’s megapixels, physical size of the sensor, aperture, pixel pitch and the minimal declination of the stars in your frame.

This is a lot to figure out in the field, and the cheat sheets aren’t small. To take a look at Frédéric’s formula, visit the Astronomical Society’s website (or Google’s English translation).

Fortunately for night photographers, there’s a simple way to apply this complex concept: I am happy to report that our friends at PhotoPills have incorporated the NPF Rule into their app, under the Spot Stars section.

Below is what the PhotoPills calculator looks like, followed by the five easy steps to figure out the best shutter speed for sharp stars.

When you open PhotoPills, the Spot Stars module is located near the bottom, so scroll down and tap.

Input your information and PhotoPills will do the NPF Rule calculations for you,

Here’s how to use it:

  1. Select your camera in the upper right corner. PhotoPills uses this to determine some of the necessary numbers to plug into the NPF Rule algorithm, such as using the sensor size and megapixels to figure out the pixel pitch.

  2. Choose the focal length of the lens (the one written on the lens, not the full-frame equivalent).

  3. Input the aperture you’d like to use. We typically choose an aperture one-third to 1 stop less than wide open. For example, for a f/1.4 lens we’d shoot at f/1.8 or f/2.

  4. For declination, tap the AR (Augmented Reality) button on the lower left corner and angle/aim the AR to the area in the sky you’d like to compose around. Note that at the bottom of your screen PhotoPills will now show your maximum exposure in landscape and portrait modes, as well as your minimum declination.

  5. The final setting to look at is Accuracy (upper right). It should say “Default.” If you keep it at Default, you’ll get a longer shutter speed and be able to use realistic ISOs such as 3200 and 6400. However, if you’re a pixel-peeper and look at the stars at 100 percent, that will result in you still seeing slight movement. You can switch from Default to Accurate and then there will be no trails at all. However, you’ll also be cutting your maximum shutter speed in half. I wouldn’t recommend this unless you are making 17x22 or larger prints—but even then, that results in the negative trade-offs that come with shooting at sky-high ISOs, which are also more prevalent in larger prints. Decisions, decisions.

Old vs. New

Let’s take a look at the old and new math.

Using our beloved Irix 15mm lens on a standard-resolution, full-frame camera, the 400 Rule gives us a 25-second exposure (400 / 15mm = 26.6 seconds).

Using the NPF Rule in PhotoPills, at a declination of 0 and set in Default mode, with the Irix lens at f/2.8 on our new favorite camera, the 24.5-megapixel Nikon Z 6, we get a maximum shutter speed of 17.26 seconds. I’d probably round that out to 15 seconds. (You want to round down, not up, to ensure sharpness.)

However, if we then shifted to Accurate mode, our maximum shutter speed would be 8.63 seconds. I’d round that to 8.

So, using the NPF Rule in Accurate, I’ve lost pretty much 2 stops of light from ye olde 400 Rule and 1 stop of light off the NPF Default mode. On a moonless night we would typically use ISO 6400 under the 400 Rule. Now, with the NPF Rule, we’d have to shoot at ISO 12,800 or 25,600 in order to get perfectly sharp stars. The Nikon Z 6 can handle those ISOs, but not many others can.

Real-World Testing

Theory is nice. But shooting for real is where we really learn some things.

I was out on the sand dunes of Death Valley a few weeks ago, and I brought my new Z 6. Curious about how the bigger sensors and higher-megapixel cameras would perform, I also borrowed the medium format 51.4-megapixel Fujifilm GFX 50R as well as my friend Kareem’s 42-megapixel Sony a7R III.

Fujifilm GFX 50r with 23mm f/4 lens

400 Rule: 400 / 18mm = 22.22 seconds

The 23mm lens is equivalent to an 18mm on a full-frame sensor, so for the 400 Rule this equaled a 22.22 maximum shutter speed. I rounded down to 20 seconds at f/5.6, ISO 6400. The resulting stars are slight dashes—elongated oblongs. They are sharp and skinny, which makes me feel I could live with this. However, if you are shooting with a 50-megapixel camera, then you’re probably making big prints, so maximum sharpness is important.

Full image from Fujifilm GFX 50r with 23mm f/4 lens. 20 seconds, f/5.6, ISO 6400.

100 percent view from Fujifilm GFX 50r. 20 seconds, f/5.6, ISO 6400.

NPF Default = 10.71 seconds

I used 10 seconds, but I was afraid to go any higher than ISO 6400 on the GFX 50r—so I just underexposed. (Not trying for art here, just testing efficacy.) To be honest, I’m seeing only the slightest of movement in the stars, not even oblong, mostly round but some of the brighter ones slightly oval. I’d be happy with these stars, event in a big print.

Full image from Fujifilm GFX 50r. 10 seconds, f/5.6, ISO 6400.

100 percent view from Fujifilm GFX 50r. 10 seconds, f/5.6, ISO 6400.

NPF Accurate = 5.35 seconds

With NPF Accurate, we’re squeezed even further. Again we are still dealing with an underexposed image, but the stars are certainly tack-sharp.

Full image from Fujifilm GFX 50r. 5 seconds, f/5.6, ISO 6400.

100 percent view from Fujifilm GFX 50r. 5 seconds, f/5.6, ISO 6400.

Takeaways: The GFX has the most megapixels of the sub-$5,000 cameras on the market, clocking in at 51.4. The dynamic range and detail are amazing, but the higher ISOs are a struggle. ISO 3200 is workable but 6400 needs some finessing. Match that with their widest lens, for which the fastest aperture is f/4, and it’s a challenge to do any dark sky work with this combo.

Nikon Z 6 with Irix 15mm f/2.4 lens

400 Rule: 400 / 15mm = 26.66 seconds

Here was my first shot using the 400 Rule, which gave me a 25-second maximum shutter speed. This forced me to use a wide-open aperture of f/2.4 and an ISO of 12,800. It looks good in standard view in Lightroom, and if posted to social media there would be no issues. However, the 100 percent crop definitely show the stars as small lines.

Full image from Nikon Z 6 with Irix 15mm f/2.4 lens. 25 seconds, f/2.4, ISO 12,800.

100 percent view from Z 6. 25 seconds, f/2.4, ISO 12,800.

NPF Default = 17.26 seconds

The stars are definitely rounder, a little oblong, but I would find this result totally acceptable.

Full image from Z 6. 15 seconds, f/2.4, ISO 12,800.

100 percent view from Z 6. 15 seconds, f/2.4, ISO 12,800.

All that disturbs me is the coma distortion that is affecting the brighter stars. Most lenses display some coma at their widest aperture, mainly near the edges of the frame and in brighter stars. With the Irix, this can be minimized by stopping down to f/2.8 or f/3.5.

Note the distortion in the brighter stars—they look like UFOs with a bright line intersecting them. This is called “coma’ and is found in many lenses. You can correct for coma by closing down your lens 1 to 3 stops.

NPF Accurate = 8.63 seconds

The NPF Accurate exposure was for 8 seconds, so I had to push my ISO up to 32,000 to get a good histogram. The stars are definitely rounder and less oblong, but it is a challenge to live in those higher ISOs. The coma is also still prevalent.

Full image from Z 6. 8 seconds, f/2.4, ISO 32,000.

100 percent view from Z 6. 8 seconds, f/2.4, ISO 32,000.

Takeaways: I’m starting to feel that I can live with the Default NPF setting in PhotoPills, which is still pushing cameras into the ISOs of 12,800 and higher. The Z 6 handles those higher ISOs very well, but I barely got the right exposure in the sky and the foreground is suffering. Blending a longer foreground exposure would be key to balancing the overall image (such as Tim did for his Bryce Canyon photo in last week’s post).

Sony a7R III with 16-35mm f/2.8 lens

400 Rule: 400 / 19mm = 21.05 seconds

I stopped down the lens to f/4 and the shutter speed to 20 seconds for our 400 Rule shot. The Sony a7R III does an excellent job at ISO 6400 and the Big Dipper looks very sharp. Looking west (left) I do notice the stars are becoming oblong.

Full image from Sony a7R III with 16-35mm f/2.8 lens. 20 seconds, f/4, ISO 6400.

100 percent view from a7R III. 20 seconds, f/4, ISO 6400.

NPF Default = 11.75 seconds

Rounding down the NPF Default to 10 seconds yields excellent results. Only a few bright stars to the far left look oval, and this is being nitpicky.

Full image from a7R III. 10 seconds, f/4, ISO 6400.

100 percent view from a7R III. 10 seconds, f/4, ISO 6400.

NPF Accurate = 5.88 seconds

We rounded up the NPF Accurate shutter speed to 6 seconds and the stars are wonderfully round. I don’t see any distortion at all.

Full image from a7R III. 6 seconds, f/2.8, ISO 25,600.

100 percent view from a7R III. 6 seconds, f/2.8, ISO 25,600.

Takeaways: I was very impressed with how the higher-megapixel Sony handled ISO 6400, and the 16-35mm lens did a superb job resolving sharp, round stars. In my testing, ISO 12,800 is also easily attainable with the a7R III, whereas ISO 25,600 is the breaking point for me, as a layer of grainy noise covers the whole image. This is still a very admirable result for a camera that gives loads of detail.

Final Thoughts

If you are a star-point seeker then you’ll definitely want to start using the NPF Rule in your workflow. I’ll be switching over from the 400 Rule to the NPF Rule at the Default setting in PhotoPills. If the shot is an absolute beauty—a 5-star shot (so to speak) that I know I’ll want to print—then I’ll use the NPF Accurate mode.

Either way, with an f/2.8 lens we will be using an ISO from 6400 to 25,600, which isn’t ideal for any camera. Don’t get me wrong, there are certainly a few cameras that handle these higher ISOs admirably, but for the best print quality we always want lower ISOs.

Because of that reality, I’ll also start committing to shooting multiple frames of a star-point scene that I can blend in post-production to reduce noise. This requires using Starry Landscape Stacker (SLS), a Mac-only software application that does an excellent job of reducing high ISO noise while keeping stars sharp. Sequator is the PC equivalent. Look for our in-depth reviews of these excellent pieces of software soon.

For the test photos above, the foregrounds were all very dark due to the moonless night and the fact that the area we were shooting was too large to paint with light. In these scenarios, I’d also advise taking an additional exposure between 3 to 5 stops brighter than your sky exposure, perhaps with LENR turned on. This will provide more detail and information in the foreground, which can be blended into the stacked SLS or Sequator image.

Applying the NPF Rule

Now here is the hardest part about new knowledge: Do you use it?

It’s up to you. We just want you to realize that star point photography is a constant balance, wherein you want to weigh the trade-offs of noise at higher ISOs versus slightly trailing stars. Understanding how your gear performs and then deciding which sacrifices to make in the field will help you create the best possible image based on the specific conditions you are shooting in.

Run some tests so that you know your personal tolerance for star sharpness versus how your camera performs at higher ISOs, then apply the 400 Rule or NPF Rule as needed while you #seizethenight!

Note: If you want to take a deeper look at some of the other “night testing” you can perform on your camera, check out Gabe’s latest video with B&H that takes a deep dive into recently released full-frame mirrorless cameras.

Gabriel Biderman is a partner and workshop leader with National Parks at Night. He is a Brooklyn-based fine art and travel photographer, and author of Night Photography: From Snapshots to Great Shots (Peachpit, 2014). During the daytime hours you'll often find Gabe at one of many photo events around the world working for B&H Photo’s road marketing team. See his portfolio and workshop lineup at www.ruinism.com.

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How I Got The Shot: Star Trails Over the Amphitheater, Bryce Canyon National Park

Star Trails Over the Amphitheater, Bryce Canyon National Park. Fujifilm X-T2, 10-24mm f/4 lens at 10mm. Light-painted with a Coast HP7. Two blended exposures of 1 second, f/8, ISO 200 and 15 minutes, f/5.6, ISO 100.

The Location

Bryce Canyon National Park is truly one of the wonders of our park system. It’s not as big or varied as some other parks, but what is has to offer is nothing short of astonishing.

Despite its name, Bryce Canyon is actually not a canyon at all. A canyon is the technical term for a gorge formed by a river. Bryce is instead a series of natural amphitheaters, or bowls, that line the eastern side of Utah’s Paunsaugunt Plateau. These bowls are filled with red, orange and white rock spires that were eroded into existence by water freezing into ice. These spires are called hoodoos. It’s the endless variety of these hoodoos that make Bryce so magical.

The Light

Standing on the rim of the canyon at one of the many overlooks affords the visitor with an awe-inspiring view. The sprawling amphitheater spreads out below you with the orange-red colors of the towering spires contrasting with the deep blue sky. This view is especially popular at sunrise as many of the viewpoints face directly east. How then, does one capture this incredible canyon at night?

As with any location, the first step is to decide which phase of the moon you would prefer to shoot in. Moonless nights (new moon) are great for photographing the Milky Way, but they leave the foreground completely black. On the other hand, moonlight (full, quarter or crescent) helps illuminate the foreground, but the brightness of the sky masks many of the dimmer stars. All phases of the moon are great to shoot under, so you just have to consider how much moonlight you actually want. My choice for Bryce would have been to shoot under some moonlight. Unfortunately for me, I was there during a new moon. Complete darkness.

Under these conditions, it made sense to concentrate on shooting the Milky Way, which I did on the first night. While I like some of those images, the lack of moonlight means I didn’t include the canyon because it was completely black. And the canyon is the hero of this location.

Figure 1. Milky Way over Bryce Canyon. Fuji X-T2, 10-24mm f/4 lens at 17mm. Twelve stitched frames shot at 30 seconds, f/4, ISO 6400.

Being in Bryce, I really wanted to include the canyon with the night sky. But how do we do that with no moon? I could have done a little painting on the foreground, which I did for the photo in Figure 2. This worked out well for some of the details, but it still did not show the entire canyon.

Figure 2. Light painting in a small area of the canyon. Fuji X-T2, 10-24mm f/4 lens at 10mm, Coast HP7.

To illuminate the entire canyon I needed something stronger than a flashlight. It needed to be the sun or the moon. Since I didn’t have the moon, I had to use the sun.

The Shoot

The next day I headed out in late afternoon to scout a location to shoot. Once I decided on the spot, I set up my camera and tripod and began fine-tuning my composition.

The goal here was to take one shot in the waning light of dusk and then another once the sky became completely dark. Back at home I would combine them together in Photoshop.

The trick was to get the right light on the canyon. Sunset would look fake if combined with the night sky, so I needed the illumination to look somewhat like moonlight. That time came around half an hour after sunset. This time of the day is called civil twilight and is great in its own right for making landscape images. (For more on this, see one of my previous posts, “Out of the Blue: The Importance of Twilight to the Night Photographer.”) I experimented with several exposures to find one that sort of looked like night. Figure 3 shows the exposure I ended up using for the final composite.

Figure 3. The canyon during civil twilight. 1 second, f/8, ISO 200.

Keeping my camera set up—not moving it one centimeter—I waited until complete darkness.

The kind of darkness I wanted begins at the time of evening called “astronomical twilight.” Depending on your latitude, this is somewhere between 1 to 1.5 hours after sunset. (Click here for a great description of the different types of twilights.)

Once the sky became completely dark, it was time to start experimenting with light painting. I changed my ISO to 100 and opened up my aperture to f/5.6 so I would capture more stars.

With these new settings I experimented with walking up and down the trail, painting as I went along. I determined that painting at an angle back toward the camera—while returning back up the trail toward my setup—created better texture in the lit areas. It also kept my silhouette from blocking the light on the trail. Had I painted while walking away from the camera, my body would have blocked some of the light from the camera’s view, thereby creating a blotchy effect.

Once I felt confident that my light painting approach was effective, it was time for the long shot. Figure 4 shows the 15-minute exposure that captured the star trails while I lit the trail.

Figure 4. Light painting during the long exposure. 15 minutes, f/5.6, ISO 100.

The Post-Production

Once I was back at the computer, it was time to put the images together in post-processing. I began in Lightroom by fine-tuning the exposure and white balance. Then with both images selected, I chose Photo > Edit In > Open as Layers in Photoshop. This command brings both of the images into Photoshop and combines them into one file, with each image as a separate layer.

Figure 5. The two images combined into one file in Photoshop.

Next I highlighted the upper layer by clicking on it. From the Blending Mode dropdown (the box that defaults to saying Normal), I chose Lighten. This blending mode automatically shows the brightest parts of all the layers it’s applied to (in this case, two layers). Voila! Now I could see the brighter canyon (lower layer) as well as the stars and the light painting (upper layer).

Figure 6. The Lighten blending mode revealing the brightest parts of each layer.

At this point I could have been done with the image. This technique works well for so many situations found in night photography, but in this case it needed a little tweaking. Because the sky was brighter at dusk during my first shot, that part of the scene also showed through when I applied the Lighten blending mode. To solve this problem, I clicked on the lower layer, made a selection of the sky with the Quick Selection Tool, and then created a Curves adjustment layer to darken the sky.

Figure 7. The Curves Adjustment over the bottom layer.

Figure 8. The Curves adjustment darkening the sky.

Because the Curves adjustment layer is below the stars layer, the adjustment does not affect the night sky. It darkens the sky only in the dusk layer. And now that the sky was darker in the dusk layer, only the stars layer would show through.

Then I needed to apply a little cleanup. The hard edge of the mask near the horizon looked a little odd, so I blurred the edge of the mask to smooth out the gradient of the curves adjustment. To do this, I clicked on the mask and increased the feather in the Properties dialog, as seen in Figure 9.

Figure 9. Feathering the mask to smooth out the transition of the curves adjustment.

At this point the bulk of the compositing was complete. Figure 10 shows the finished composite of the stars layer and the dusk layer.

Figure 10. The completed composite.

Once the images were put together I was able to judge the overall look of the picture. I felt it was still a bit dark and the color somewhat off, so using more adjustment layers in Photoshop, I fine-tuned the exposure and color.

Figure 11. The final image after fine-tuning white balance and exposure.

Wrapping Up

The moral of the story is that you can’t always get what you want, but if you try sometimes … well, you get the picture. Matching the locations, moon phase, time of year and our creative vision can be a daunting task—and sometimes an impossible task. But with creative thinking, and a full grasp of all of your available tools, you might just find you can get what you need.

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