Night Sky Planning

Hidden Lake – Glacier National Park, Montana

While presenting a recent night sky image to our photography club at work this week, I was asked a lot of questions about how to plan those kinds of shots. I hadn’t thought about it for a while, but there can be a lot that goes into it if you have a particular image in mind. My goal is often to try to line up something in the sky (usually the Milky Way) with a landscape scene. To make it work I need to figure out when those things will line up, when the sky will be dark enough to see the stars, and how much light will I want on the landscape, all while also keeping track of the weather and sometimes tides. In this post I will list some of the tools that I use and show how I used them to plan some recent images.

Apps for Planning

I do most of my work on Windows PCs and Android phones. I am also willing to pay for apps that I believe provide good value. Most of the tools I list here will be available on any platform – but I don’t promise that they will be free.

For basic sunrise/sunset, moonrise/moonset, moon phase and Milky Way visibility I primarily use PhotoPills and The Photographer’s Ephemeris (TPE). TPE has a simpler interface and provides an easy way to find a location on the map, choose a date/time, and see where and when the moon and sun will rise and set. PhotoPills has more options (and accordingly has a longer learning curve) but their planning module better helps me to figure out the different phases of twilight along with where the Milky Way core will be. You can save the location, time and date into a plan that you can reload later for reference.

If I want to see how the stars will look in the sky, along with how the Milky Way will be oriented, I use a free open source program called Stellarium. This lets me set the location and date and then scroll through time to see how the objects in the sky move. The combination of Stellarium and PhotoPills allows me to clearly picture my shot. Once I get onsite, I use the “Night AR” feature in PhotoPills to fine tune my plan. This turns on your phone’s camera so you can see the scene on your screen, and then overlays the night sky on top of it. By dragging your finger on the screen you can change the time and see where everything will be at the time of your choice. I’ll show how this works below.

My favorite weather app is Dark Sky. Over time I have seen it do a remarkable job of predicting weather conditions. Clearly I am not the only one who likes it, as Apple recently bought the company for their own use and shut down the Android version of the app. For the time being at least, I can still access their weather data through their website as well as in other Android apps (I am now using “Today Weather” which lets me select Dark Sky as my data source).

I also recommend the Clear Sky charts on ClearDarkSky. This site is intended for astronomical use and predicts the cloud cover, transparency, seeing, smoke and other parameters that can impact your ability to see the stars. It has a limited number of locations and only looks out 48 hours into the future, but it has rarely let me down when I’m trying to decide whether it is worth staying up all night for a shot.

Example: Hidden Lake

Hidden lake is a stunning location near the Continental Divide in Glacier National Park. The lake is ringed by mountains and the viewpoint is reached by an (uphill) hike of 1.25 miles from the Logan Pass parking lot. During my recent trip to Montana, I decided I wanted to try capturing the Milky Way from this viewpoint. I started with PhotoPills as shown below. I could see that the Milky Way core would be SSW of the viewpoint at 10:40PM just as Astronomical twilight ended and the sky became fully dark.

PhotoPills Prediction for Hidden Lake

I checked the moon phase as well, and observed that there was a 13% moon that night which would set at 10:20PM. My first choice would have been to go the next night, so that the moon would still be in the sky at the end of twilight to help light the landscape. I made the decision to go this night, though, as the weather predictions were more clear and I knew I wanted to see the stars. Because of this, I decided to arrive early enough to make sure I could capture some late twilight images that I could combine with the darker star shots in order to improve the image quality. I also checked the scene in Stellarium as shown below, where I could see that the stars would be angling up and to the left in my scene and that both Jupiter and Saturn would be visible.

Stellarium Prediction for Hidden Lake

I arrived on site just after sunset and used PhotoPills’ Night AR to decide where to set up my camera. The image below is a screen capture from my phone, showing that the stars would line up just left of Bearhat Mountain at 10:30PM – just as I had hoped.

The image at the top of this post is the resulting landscape image. Below is the portrait version, which was my primary goal for the evening. This is a combination of two shots. The first was taken at 9:52PM while the moon was still in the sky so I could get some light on the foreground. I used a 14mm f/1.8 lens (at f/2) for the image at ISO 1600 and an exposure time of 20 seconds. I took the second image with the same settings at about 10:30PM to capture the stars and then combined them in Photoshop. I was careful not to move the camera between shots to make it easy to line things up.

Hidden Lake and Stars – Glacier National Park, Montana

Example: Bowling Ball Beach

Bowling Ball Beach is a popular spot for photographers, with large boulders lined up along the beach that make great foregrounds. I knew I would be in the area and decided to check if there would be any opportunities for night shooting. Looking at the PhotoPills prediction below, I saw that I would have a crescent moon setting at 9:03PM and that the Milky Way core would be visible to the south west. Twilight ended at about 8:45PM so the stars should be visible at that time. I checked a tide app (I use an Android app called “Tide Prediction”) and verified that it would be low tide at this time as well. As long as the skies were clear (never a sure thing in that area) things lined up nicely!

PhotoPills Prediction for Bowling Ball Beach

I made the trip down to the beach and looked for some attractive rocks. I used the Night AR feature (below) to pick where to set my tripod and have the stars appear between two large boulders (they are a little dark in this image but were clear on my screen).

Night AR at Bowling Ball Beach

And here is the resulting image. Even though I knew the moon was in the sky, I took a foreground image during twilight as well so I would have options for blending. I ended up using that twilight image as it had significantly less noise than the images I took later.

Bowling Ball Beach and Stars – Mendocino Coast, California

Example: Olmsted Point

Here is one more quick example where I didn’t really do any serious planning. I knew I was going to shoot the Milky Way at Olmsted Point in Yosemite but hadn’t really decided where. I arrived in the early afternoon and did some scouting with PhotoPills before moving on for an afternoon hike. I came back later and made use of my scouting to create some images. Here is one of my Night AR screen captures:

Olmsted Point Night AR Prediction

I saw from this that the Milky Way would be stretching over this tree a little after 10:00PM. I ended up going with a landscape composition to get more of the night sky and the result is shown below.

Stars and Rocks – Yosemite National Park, California

Hopefully this is helpful – feel free to ask questions in the comments!

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