In this video I will show you the photo session and Photoshop editing of the images to create a star trail and 4K time lapse.
We will visit the location before the night shooting session in order to see the access and possible setup places. I will also show you how to shoot time lapse photography, the camera settings and how I took the dark frame used to subtract the noise from the image once the star effect is created in Photoshop.
Equipment used to get this shot
Time lapse Video Tutorial
Download time-lapse image sequence
For night photography, it’s not necessary to have the most expensive camera out there. The most expensive the better the results of course but the lens you are using is far more important in my opinion. Wide aperture lenses give you better results, you capture more light in less time. If you don’t own one, you can borrow one for one night if you don’t want to spend the money.
If you don’t have a remote trigger, you can also shoot in Burst Mode if your camera allows you and simply tape the shutter button. But you can find really cheap remote triggers and even though wireless are a bit more comfortable to use, a corded one will do the job too.
Make some planning before you go out at night
Scout the location during daylight if possible. The location was 20 min. away by car so I visited the place on midday to see the terrain, possible setup locations, etc. Take a flashlight for light painting the foreground and a head lamp for your safety, you will walk safer and you will be seen by others.
Proper clothing is also important because nights are usually colder, check the terrain and wear proper shoes. In my case I was wearing tall rubber boots because there was a lot of tall grass full of bugs and thorns. Think about bugs and other creatures so take with you bug spray especially if you’re going to shoot near a water source. Take extra batteries for your electronic equipment and maybe even something to eat and drink, you will out there for a few hours.
Weather is critical for night photography
If you want to photograph the milky way or the stars, you need clear dark skies and no moon, otherwise you will not see the stars. Also avoid light pollution by shooting away from towns or cities. Elevated locations are also great to avoid pollution and have a clearer view of the stars and even see the milky way with the naked eye. There are plenty of websites that will give you the lunar phase but it’s usually on the middle of the month where there is no moon on the sky (depending on your hemisphere).
Also check clouds coverage charts and make sure you have no clouds, because the stars will no be visible. On the internet you can find applications that will give you the forecast but you can also just watch the TV and check the local forecast.
Setup the camera and prepare for hours of shooting
Setup your tripod and make sure you open the legs wide enough to avoid movement in case of wind and wrap the camera strap to the tripod so it doesn’t hang around moving your camera or getting in front of the lens.
Focusing and making the composition
If the stars are very bright you can focus to infinity using by pointing to the brightest star on the sky. If there is city lights on the distance try to use those lights to focus. If you carried a flashlight you can use it to illuminate into the distance and focus that way. Once you focus, change the focusing mode to manual.
Now it’s time to make the composition. On manual mode, pump the ISO very high 1600 or above and the lowest F number and set an exposure of 30″ and try from there. The objective is to get a photo that is bright enough so you can see what’s in the frame. You will get an unusable image with lots of noise but it will help you make your composition.
Camera settings for time lapse photography
Once you have the right composition set the camera settings for the time lapse shooting. Set the camera and focus mode to Manual and set the widest aperture of your lens (lowest F number), ISO of 800 and exposure time of 30″, take a test shot and of course shoot in RAW. Your objective is to get a decent amount of stars and a usable amount of noise so you will have to balance it. The foreground should have some light on it as well, unless you want to have a silhouetted horizon line. If you increase the ISO you will get more noise but also brighter stars and brighter foreground (expensive cameras handle noise a lot better).
You can also increase the exposure time, but to go beyond 30 seconds you have to switch to Bulb mode and use the remote trigger. Try with 40 seconds and same ISO and F number and you will get longer star trails and brighter image. Change one variable at a time and asses the result. Make as many test shots as you need and make sure the focus is right, the last thing you want is to get home after 3 or 4 hours of shooting and find out that the pictures are out of focus.
Program the remote trigger
Once I found the right settings for my photos, I programmed my remote control by setting to Timer Mode with and Long exposure time of 40 seconds and an Interval of 5 seconds between each shot and hit the play button.
Settings used for this particular session
- Aperture: f2.8
- Exposure: 40 seconds
- ISO: 800
- Interval: 5 seconds
Taking the dark frame for noise subtraction
Before I started to shoot the time lapse sequence I took the dark frame. A dark frame is a photo that you take without any light hitting the sensor of your camera. So I put the lens cap on and I took a shot using the exact same settings I have set for the time lapse sequence. The result is a dark image with the sensor noise recorded on it. This will be used later when we make the star trail image to subtract this noise from the stacked images.
The Nikon D7100 has a built in Long Exposure Noise Reduction (LENR) function which can take the dark frame after each image automatically and subtract the noise when it processes the image. The downfall of using the built in function is that the picture takes twice as long to be taken (40 seconds for the normal exposure and 40 seconds to take the dark frame).
If you’re going to make a time lapse and activate the LENR function on your camera, it will take ages to make a 200 photo series. A better approach when making star trail photography, is to only activate this option when you take the last shot when you make the light painting. That way you will have an image where the foreground is well lit and free of noise which you can compose in Photoshop using a simple layer mask.
The reason why I took this dark frame on a separate black image is because I want to show you how you can use it in Photoshop to remove noise from your final composition but it’s not as effective as the built in function on your camera.
Edit the images in Lightroom
Import all the images you took in Lightroom. You can use the same images to make the time lapse and the star trail image Edit the first image to your liking and then select all images and click the Sync… button to apply the same settings to all the images. When you’re done, select all the images you want to use for your star trail and time lapse and export them File>Export.
How to make a star trail photo in Photoshop
Making a star trail photo in Photoshop is really easy. Open Photoshop and go to File>Scripts>Load Files into Stack and locate the photos you exported from Lightroom. Load the photos you want to use for your star trail, with 100 photos you will have more than enough (even less if you use exposures longer than 40 seconds). It’s not necessary to align the images because we took them using a tripod.
Select all the layers except the last on on the bottom and change their blend mode to Lighten. The effect will be created but we have to clean the image from airplane trails.
Cleaning the image from airplane trails is time consuming depending on how many images you used to make your star trail. In my case I used only 60 images. The process is the following. Disable the visibility of all layers except the bottom one and start enabling them back one by one and inspect your image. When you see a new airplane trail, use the Spot Healing Brush Tool to remove it and continue with the process until you’re done.
Compose the light painted foreground image. With the settings that I used to shoot all the images, the foreground is a bit too dark so after I finished shooting the sequence, without moving the tripod, I took another shot and I painted the foreground with a flashlight. I used this image to put it on top of my star trail and used a layer mask to blend the images. Use the Opacity setting to adjust the amount of light.
Use the same images to make a time lapse
If you want to take advantage of your shooting session, you can use the same image to also create a timelapse video but you will need far more photos than just 60. For a 10 seconds video at 25 frames per second you need 250 images and if each photo takes 40 seconds to be taken, that’s 10000 seconds (about 3 hours of shooting if you also add 5 seconds of interval between shots). In other words time lapse photography takes a lot of time for only a few seconds of video.
In Lightroom I used the same images but I used a 16:9 crop and exported the images again. You can create the time lapse video straight from Lightroom using the Slideshow module and the time lapse presets for lightroom but exporting the time lapse takes about 15 minutes depending on the amount of images you export. For this tutorial I used another software called Sequence to create the 4K the time lapse video.