The Milky Way rises over Arches National Park
If you're interested in capturing images of nebula and galaxies, you'll want to check out my new Deep Space Course! This course has over 9 hours of content which will teach you how to find, photograph, and edit deep space objects. All you need to get started is a DSLR, star tracker, and telephoto lens! Click here to read more about the Deep Space Course.
As you might already know, a star tracker is one of the best ways to capture better images at night. However, they can be quite difficult to use properly, and there isn't much good information online. Therefore, I set out to create a comprehensive tutorial package for each star tracker, including the iOptron SkyTracker Pro and SkyGuider Pro, as well as the Sky-Watcher Star Adventurer and Star Adventurer Mini. These courses are designed to show you the entire process for capturing amazing images at night. While some of this information is covered in this free tutorial page, I've gone much more in-depth on every subject and put it into an easy-to-follow video format. Most importantly, I've included hours of tutorial videos that will show you exactly how to setup your star tracker in the field! For more information, head over to the Star Tracker Tutorials page!
If you want to learn how to edit your astro photos, then you'll love my new Astrophotography Post-Processing Course. It's jam packed with over 7 hours of tutorial videos! For beginners, I've included basic tutorials for Photoshop, Camera RAW, and Bridge, which will help you learn the main features of each application. I've even included some of my own RAW files, so you can follow along and practice if you don't have your own images yet. For advanced users, I've created multiple full-length workflows for nightscape images as well as deep space astrophotography. One of the most important skills we'll be covering is exposure blending using Luminosity Masks. This technique will allow you to cleanly, and easily, blend your foreground and sky images. For more information, head over to the official Astrophotography Post-Processing Course!
First, you need to know when and where the Milky Way will be in the sky. For those of us in the northern hemisphere, the core of the Milky Way is always in the southern sky. Keep in mind, "Milky Way Season" runs from April - October in most cases. In the winter months (November - February) the core is not visible. In Spring, the Milky Way will be in the Southeastern sky very early in the morning (3-5AM). In the Summer, the Milky Way will be due South and will be up all night. In the Fall, the Milky Way will be in the Southwest portion of the sky early at night (8PM-12AM).
I highly recommend using Stellarium, a free Desktop application. It is also available on the App Store and Google Play for $2.50. Stellarium allows you to select any location on Earth and see what the night sky will look like. I've been using Stellarium to plan all of my night photos for over a year now. The smartphone app has everything you will need when shooting out in the field. One thing to be aware of: Stellarium does not account for timezone differences. This can make planning a photoshoot confusing if you are using a location in a different timezone from your own. Click here for more information and a fix for that particular issue.
You should also get TPE (The Photographer's Ephemeris) to help plan out your photos. This app is a must-have for landscape photographers, and it also includes great information for nightscape photographers. It will show the path of the moon, if it's above the horizon, the civil / nautical / and astronomical twilight times, as well as the sun / moon rise / set times. This is one of my most-used apps when I'm doing photography.
Don't forget, you can also look North for a different take on the Milky Way. I've found that some of my favorite Milky Way photos taken recently have actually be facing North, not South.
Trillium Lake - MidnightThe Milky Way shines brightly over Trillium Lake. Mount Hood can be seen in the distance
Next, you need to find a location with dark enough skies. If you are anywhere near a major source of light pollution the Milky Way will probably not be visible. I highly recommend using this Dark Sky Map as a guide to finding dark locations near you. Remember, the core of the Milky Way will be in the southern sky, so it's best to find locations that don't have any orange or red locations south of your position. Living in Northeast Ohio, it is very hard to find suitable locations for photographing the Milky Way. In my experience, even a Yellow area can be dark enough to get some good shots. If you are lucky enough to live near a dark sky with no light pollution, you will have a much easier time taking and editing your Milky Way photos.
There's a few different options for mobile apps. First up is the Light Pollution Map - Dark Sky Finder Astro Tools. One feature I love in this app is that you can see whether light pollution on the horizon will affect you. If you press and hold a location on the map, a circle will form around the point. You can now see if light pollution will be visible on the horizon. This app also has the ability to show the Aurora location and strength. The app is free, but some more advanced features require you to purchase the Pro edition.
If you just want a simple Dark Sky app, then I'd recommend this one.
To understand the role light pollution will play in your Milky Way photos, take a look at the 2 images below. The first image was taken in Joshua Tree National Park looking southwest. The second image was taken at Black Canyon of the Gunnison National Park looking south. Use the Dark Sky Map to see the difference in Light Pollution at each National Park.
Light Polluted skies in Joshua Tree National Park
Dark Sky at Black Canyon of the Gunnison
I recommend using Clear Dark Sky forecasts. These are a bit tricky to understand at first. Basically, you want as many rows as possible on the chart to be dark blue. The darker the blue, the better the conditions will be. This forecast is specialized for Astronomers and Astrophotographers with telescopes, so it may be a bit overkill for normal photographers. I've found it's more accurate than a standard forecast though. Another important thing to keep in mind is the moon. In order to get great Milky Way photos, the moon can not be out. Therefore, it's best to wait until the new moon each month, or use Stellarium to see if the moon will be below the horizon when you are out.
Any modern DSLR can take decent photos of the Milky Way. The major problem you will have with any camera is noise / grain. The camera's electronics always produce a low-level of 'noise'. Have you ever heard white noise when turning on your speakers or headphones? Once you start playing music, the white noise is no longer audible. It's a similar concept with cameras. You need to capture enough light to overpower the camera's 'white noise'. Older cameras have more 'white noise' and will perform worse in low-light scenarios. This concept is called Signal to Noise Ratio (SNR). Click here to learn more about SNR.
The next thing to consider is your camera's sensor size. The larger the sensor, the more light it can capture. Many entry level Crop-Sensor cameras will start to see heavy noise around IS0 800. A Full-Frame camera can shoot at much higher ISO's with better noise control. Full-Frame cameras also allow you to capture a wider view of the sky, provided you use a wide-angle lens; this also allows you to take longer exposures without any star movement. A Wide Angle lens can also help with Milky Way compositions, as you will have room for the Milky Way and foreground. For more information on crop-sensors vs full-frame sensors, read this article.
I want to be very clear here, the best way to get higher-quality Milky Way photos is to capture more light. I recommend using a long shutter speed to capture more light. You could buy the most expensive camera in the world, but the photos still won't look great at the typical ISO 6400, f/2.8, and 25 second shutter speed. That's because the camera still only captured 25 seconds of light. If you capture 4 minutes of light though, the images will be vastly better. Therefore, even an entry-level DSLR with a long shutter speed can capture great Milky Way photos. There's just one problem though, we can't take 4 minute long photos without the stars blurring.
One of the best purchases I made for Milky Way photography was a star tracker. You can read my Star Tracker Tutorial on my blog. This device moves the camera at the same speed as the stars, allowing you to take much longer photos without star trails! Since you are now capturing much more light, your lens' aperture and camera's ISO performance no longer matter as much. For example, when using my 14mm lens with a star tracker, I can now take a 4 minute long photo and capture up to 8 times the amount of light! Normally I'd be limited to a 20 second exposure before the stars began to show movement. Having had a chance to use a star tracker on my 2017 roadtrip, I would recommend purchasing this device over an expensive new lens. Even with the best, most expensive, wide angle lens, you will always be limited to a ~20 shutter speed. Therefore, your images will always be grainy. The star tracker can help produce beautiful, clean, detailed images even with a relatively cheap lens and entry level camera! I cover Star Trackers in depth further down in the tutorial.
If you currently can't afford a star tracker, there is another option for higher quality night photos. I recommend shooting multiple exposures in order to reduce noise. This process is called Median Stacking. This blog by Pat David does an excellent job of explaining the process in detail. You will need 10+ images to effectively remove noise. I recommend using Sequator to stack your images. It does a great job with wide angle photos and deep space images! Click here to watch my YouTube tutorial for Sequator, where I show exactly how to use it.
*Sony Users: There is currently a major bug with some Sony mirrorless cameras, including the a7SII, a7RII, and a7RIII. Basically, the camera will automatically remove stars in your image, in an attempt to reduce noise and hot pixels. This flaw has been identified by the astro community and reported to Sony, who have yet to issue a fix. For more information, visit the Lonely Speck website.
A lens that has bad aberrations can ruin your Milky Way images. This article explains exactly what Coma is. Many lenses produce awful coma, or star distortion. This causes the stars to lose their sharp, spherical look. The example below was taken with the Sigma 35mm Art lens at f/1.4. I cropped in heavily to the upper-right corner of the image. These "winged stars" are actually the result of astigmatism in the lens, often referred to as coma. If you stop the lens down to f/4, the stars will look normal. However, we've just lost 8 times the amount of light! Again, this is where the star tracker can come in handy. You can take a longer shutter speed with the f/4 aperture and get the best of both worlds, sharp stars and lots of light. Some lenses have bad coma that affect stars across the entire image. Therefore, it is recommended to use a lens with minimal coma for your Milky Way photos.
I recommend reading this excellent article on Lens Aberrations over at Lonely Speck, it describes all of the major aberrations you may notice when photographing the stars.
Sigma 35mm f/1.4 coma
The lens you choose is one of the most important factors in capturing good Milky Way photos. You can have the best camera body available, but a bad lens choice will ruin your star photos. I've spent many hours researching the best lenses for night photography. Every lens listed below is wide-angle, which will allow you to capture nightscape photos with a foreground.
If you want higher quality nightscapes, you'll want to create panoramas using a 35mm, 50mm, or even 85mm lens. I personally use the Sigma 35mm Art lens when I do any night-time panoramas. The Sigma 50mm Art would be another great option. Keep in mind, doing panoramas at night is quite hard. I would not recommend this approach for beginners. Wide angles lenses will make everything much easier.
Out of all the lens manufacturers, the clear winner, for the price, is the Rokinon / Samyang brand. They make good, cheap, manual focus lenses. Oddly enough, many Nikon and Canon lenses are awful for taking Milky Way photos. Below is a list of the top Astrophotography lenses:
First up is the acclaimed Nikon 14-24mm. This lens is quite expensive at $1,900, especially compared to the $350 Rokinon 14mm. The Nikon has fairly minimal vignetting, distortion, and coma at f/2.8. This lens doubles as a fantastic lens for landscapes and waterfall photography as well. It is also very large and heavy, especially when compared next to the Rokinon. This is currently my main Milky Way lens.
The Tamron 15-30mm is one of the best wide-angle lenses on the market right now, and it costs $700 less than the Nikon! While it may capture slightly less light than the Nikon, it performs at a high level. In fact, it actually out-performs the Nikon during the day! The Tamron also has Vibration Control built in (you'll want to turn it off when photographing the Milky Way though). It is roughly the same size and weight of the Nikon 14-24mm (big and bulky). If you don't want to spend nearly $2,000, but you want a high-quality astrophotography lens, this might be your best bet! Check out my direct comparison tests of the Tamron 15-30mm vs the Nikon 14-24mm for more information.
The new Sigma 14-24mm is another great wide-angle lens for astrophotography! It transmits slightly less light than the Nikon, but the Coma performance is better, and the lens costs $600 less! You can see a direct comparison of the Nikon 14-24mm and Sigma 14-24mm here.
If you don't want to spend over $500 on a lens, then I recommend purchasing the Rokinon 14mm. You can head over to my blog, which has multiple comparison images of the Rokinon 14mm vs the Nikon 14-24mm. Keep in mind, this lens is also listed under different names, including Samyang or Bower. They are all the same lens, just for different geographic markets. I'd recommend this lens for beginners and professionals alike. It is a cheap lens, yet the image quality is quite good, even better than some lenses that costs thousands of dollars. The Rokinon 14mm has no coma and is sharp from corner to corner. Another thing I love about this lens is its massive focus ring. Most lenses have a very small focus ring, (if you move the focus ring a millimeter past "Infinity" it won't be sharp). The Rokinon allows you to rotate the focus ring substantially without losing sharp focus. I should also mention that this lens is Manual Focus only, no autofocus. However, this is irrelevant when doing Milky Way photography, as Auto-Focus wouldn't work anyway.
There are 2 bad things about this lens. First is the awful vignetting. When compared against the Nikon 14-24mm, you can see that the Rokinon loses a substantial amount of light due to its vignetting. Personally, I find this to be a big problem. The images taken with the Rokinon are significantly darker than the Nikon or Tamron. The second problem is the mustache distortion, but it's not very noticeable unless you have a straight horizon in the center of the frame. To be clear, almost all of the Milky Way photos in my Nightscapes Gallery were taken with this lens. It can definitely get the job done, but it will take more editing in post-processing to get the images up to an acceptable level. Head over to my YouTube channel to check out a full-length post-processing video made specifically for the Rokinon 14mm!
In 2017, I had the opportunity to test the Tamron 15-30, Nikon 14-24mm, and Rokinon 14mm against one another at Cherry Springs State Park. This review should give you a very clear look at the differences between each lens, and help you decide which option might work best for you. Click here to read the review.
The Rokinon 14mm is a great Milky Way lens
Another lens I like is the Sigma 35mm Art. It produces very sharp images, but it does suffer from pretty severe coma at f/1.4. However, at f/2.8 the coma is gone! The 35mm focal length also changes how you compose your Milky Way photos. Compared to a typical 14mm lens, you won't have much room to compose your scene. If you plan to capture a typical nightscape scene, with a foreground and the Milky Way overhead, you'll likely need to create a panorama. This can be very difficult to do in the dark, and I wouldn't recommend it for beginners. Plus, you'll also have much less Depth of Field with a 35mm lens, compared to a 14mm lens. At f/2.8 on a 14mm lens, you can focus on the stars and the foreground will be sharp too! You can read a more in-depth review, complete with sample images, on my blog.
If you have a Sony, Pentax, Fuji, or Olympus camera, head over to Lonely Speck website for even more lens recommendations and details! Ian has compiled a large list of lenses for every camera brand and sensor size that work best for Astrophotography. This article should help you find the best lens!
In order to capture a nice foreground and the Milky Way with a 35mm or 50mm lens, you will likely have to create a Panorama. Check out this fantastic guide by LonelySpeck Photography to learn how. They have tons of informative guides and information on their site, be sure to look around!
The lens you choose will drastically alter how your Milky Way images look. I love using a 14mm lens because I have plenty of room for the foreground and the Milky Way. Anything over 35mm is too tight to capture a foreground element, unless you create a panorama. Remember, these focal lengths are for Full-Frame cameras.
If you are using a Crop-Sensor camera, the image will be magnified by a factor of 1.5. The photo below shows this difference between a 14mm lens on a full frame camera and a crop-sensor camera. The 14mm lens essentially becomes a 21mm lens on a crop-sensor camera.
When it comes to Milky Way photography, it is crucial to capture as much light as possible. T-Stops measure the transmission of light through the lens. Ideally, the f-stop and T-stop would be the same. For example, an f/2.8 lens would transmit 2.8 T-stops of light. This is usually not the case. Most lenses don't transmit as much light as their aperture would indicate. For example, the Nikon 14-24mm f/2.8 transmits T/3.0 stops of light.
I recommend watching this informative video by Tony Northrup on the difference between f-stops and T-stops.
Be sure to visit DXO Mark and see what the T-stop rating is for your lens. You may be surprised how much light you are "losing". You can also compare most of the Astrophotography lenses I listed above, and get an idea of which lenses will let the most light in. Remember, the more light that you let in, the cleaner your images will be.
I'm sure this is what most of you came for. Everyone always wants to know more about what camera settings were used. For astrophotography, things are pretty simple. However, there are different methods you can use to create better images, like photo stacking or simply taking longer exposures (think 4+ minutes!). Let's break down each camera setting first, and see how they affect our night time images.
ISO is a very important camera setting to understand for Milky Way photography. There are a lot of misconceptions about ISO, and what exactly it does. Generally, it is said that "increasing the ISO increases the camera's sensitivity to light". For the more experienced photographers, I recommend reading this ISO Tutorial by Lonely Speck. It covers ISO very well, especially in context with Astrophotography.
Click here to see the difference between the ISO Stops, from 100 to 6400. The only setting I changed between each photo was the ISO.
Remember, there are only two ways to capture more light: a longer Shutter Speed or a wider Aperture. We want to gather as much light as possible through Shutter Speed and Aperture. Since we can only shoot for a certain length of time (before the stars become blurred), we are limited by the Shutter Speed. The lens aperture only opens up so wide. Most Wide Angle lenses are limited to f/2.8, although some can open up to f/1.8 or even f/1.4.
It is generally better to use a higher ISO in-camera, as increasing the Exposure in Post-Processing tends to ruin image quality. However, at some point, increasing the ISO will actually cause you to lose Dynamic Range. This ISO value changes for each camera. Therefore, you may want to shoot at a lower ISO, say 1600, and brighten the Exposure as needed in your RAW editing software.
To make things even more confusing, some cameras are ISO Invariant, which means you can use any ISO and brighten the photo in Post-Processing without any loss in image quality. You would mainly use this feature to save data in your highlights and reduce noise. Note, this only applies when shooting in RAW. Read my blog post on ISO Invariance to learn more. To understand how to use an ISO Invariant camera to its fullest potential, check out this article by Daniel Laan.
The best way to reduce noise / grain in your images is to capture more light. That means a longer shutter speed or wider aperture. Increasing the ISO does not capture any more light! Watch the video below for more information, as well as some tips to reduce noise in Adobe Camera RAW and Photoshop.
When photographing faint stars, it's imperative to use the widest Aperture possible. Ideally you have a lens that opens up to at least f/2.8. If not, you should seriously consider buying a new lens for astrophotography. Remember, a f/2 lens can get double the amount of light of a f/2.8 lens. A f/1.4 lens can get four times the amount of light of a f/2.8 lens! That's a huge difference!
If you use a wide-open aperture, like f/1.4, you will likely notice vignette in the corners and significant coma. If you stop-down to f/2 or f/2.8 these problems tend to disappear. This is another advantage to buying a lens that can open up to f/1.4 or f/1.8. For example, you have the Nikon 14-24mm (an f/2.8 lens) and you stop down to f/4. The vignette will be reduced, but you would now be getting half the amount of light. Not good for Milky Way photography. If the starting point is f/1.4 though, you can stop down to f/2.8 and still capture a lot of light and not have to deal with heavy vignette or bad coma. My Sigma 35mm Art lens has such bad coma, that I have to stop down to f/4 to get reasonable sharp stars! Make sure you do your research before you buy your next astrophotography lens!
The Shutter Speed you choose will have a massive impact on your astrophotography images. Most people begin by taking 1 single exposure. Therefore, there Shutter Speed needs to be fast enough to avoid star trails. By now, you've heard of the 500 Rule, which states "Take 500 divided by the focal length of your lens for sharp stars". Lets take a 35mm lens for example. 500 \ 35 = 14.2 seconds. Therefore, your shutter speed would need to be 15 seconds or less for acceptably sharp stars. However, I personally don't agree with the 500 Rule. I find the stars will show too much movement. I personally use the 300 Rule most of the time.
If you want high-quality nightscapes, I would recommend using a much longer shutter speed. For example, I normally take 4 minute long photos to capture enough detail in my foreground. This also helps to drastically reduce the noise in my images. Taking a longer exposure is the simplest way to create better images! Keep in mind, you'll need to blend in another exposure for the sky, as the stars will show motion after 4 minutes.
Alternatively, if you have a Star Tracker, you can use a much longer shutter speed. However, we now have the opposite problem as mentioned above. Instead of the stars moving over the course of the exposure, now the foreground will become blurry. This can cause image blending in Photoshop to become considerably more difficult. When using a star tracker, your shutter speed is limited to the accuracy of the star tracker. For example, I normally shoot 4 minutes with a 14mm lens without noticing star trails. That allows me to capture over 4 times the amount of light than a standard 20 second exposure! If I'm using a 100mm lens, I can normally shoot up to 60 seconds without motion blur. That means I'm capturing almost 16 times more light than a standard 4 second exposure!!
When I am photographing the Milky Way, I want to have as neutral a White Balance as possible. With that being said, most of my Milky Way images tend to have a blue or purple tint. Light Pollution, Air Glow, and environmental conditions can all change the colors in the night sky.
I normally set my White Balance around 4000 - 5000 K for the best results. This tends to make the sky more blue / grey / green. Most of the photos in this tutorial were taken in that White Balance range. If you are shooting in RAW, and you should be, you can always leave the White Balance set to Auto. Once you get into Lightroom or Camera RAW, you can easily adjust the White Balance to suit the image.
To get realistic colors, use the preset 'Daylight' White Balance. Read Roger Clark's blog post on Night Sky Colors for more information. The image below was taken on a dark night in Canyonlands National Park, Utah. This photo is a (roughly) accurate representation of the true night sky colors. The green color is called Air Glow, which is similar to the aurora. The predominate yellow color is because most stars in the night sky are yellow/orange/red.
More accurate night colors
If you begin taking your Milky Way photos at Nautical Twilight (~one hour after sunset), the sky will have a blue cast to it. Therefore, you may need to re-adjust your White Balance once Astronomical Twilight arrives (~1.5 hours after sunset). Personally, I always wait until Astronomical Twilight to begin taking my Milky Way images. I recommend using The Photographer's Ephemeris App to see what time these occur.
Again, the real colors of the night sky tend to be quite warm. Using the Daylight White Balance may be scientifically accurate, but it doesn't always make for a pleasing photo. As the artist, it's your decision to make. What White Balance looks best to you?
Daylight White Balance - 5500 K
Custom White Balance - 4000K
Fluorescent White Balance - 3800 K
Tungsten White Balance - 2850 K
Focusing at night should be easy. Just set your lens to Infinity and shoot. Most lenses don't work that well unfortunately. If the focus ring is even slightly off, your stars will no longer be sharp. Manual focus lenses are much easier to focus with at night, as they have a lot of distance in the focusing ring. This is why I love using the Rokinon. I can move the focus ring quite a bit and still have sharp stars. When using most Auto-Focus lenses, the slightest movement on the focus ring will ruin the sharp focus. There are a few different ways to focus at night.
Sometimes you can't see anything through Live View. It may be that the lens is too out of focus, double check that the Focus Ring is on / near infinity. You should also be using a lens with an aperture of at least f/2.8. If you are using a kit lens that doesn't have the capability to open up to f/2.8, it will probably be too dark on Live View to see any stars.
Keep in mind, using Live View will quickly heat up the camera sensor. This sensor heat will cause unwanted side effects in your final images; these problems are covered further down on the page. Therefore, try to be as quick as possible when using Live View, especially on warm nights. Then again, having sharp stars is critical. Make sure that your stars are 100% sharp before continuing on.
Another problem you will encounter when shooting at night is star trails. While these can make for excellent photos, we generally want our stars to be tack-sharp. Therefore, we need to limit our exposure length so that the stars don't appear to move. This is another great reason to use a very wide lens (24mm and lower), you can have longer exposure times without any visible star movement. If you are interested in learning how to create a Star Trails image, check out my Star Trails Tutorial.
As I stated in the Shutter Speed section, most photographers recommend the 500 Rule when taking Milky Way photos. The 500 Rule states: to prevent star trails, take 500 divided by your lens' focal length.
In my experience, the 500 Rule is just a bit too long. You will likely see the stars moving.
Another problem you will have is that the camera may not give you the exact shutter speed. For example, you can't take a 21 or 14 second photo. Anything longer than 30 seconds has to be manually timed on Bulb Mode.
Below you will see 4 heavily cropped images, each taken with a different "Rule" (500, 400, 300, 200). If you look closely, even the 300 Rule has a small amount of movement. Below are some quick Shutter Speeds for reference:
500 / 14mm = 35 seconds
400 / 14mm = 28 seconds
300 / 14mm = 21 seconds
200 / 14mm = 14 seconds
**Note: all these numbers are for Full Frame Cameras. If you use a Crop Sensor camera you must multiply your focal length by 1.5 to get the proper shutter speed. 500 / (14mm * 1.5) = 24 seconds
Another thing to consider when choosing your 'Rule' is the amount of light captured. Remember, it's crucial to capture as much light as possible at night; the more light you capture, the less grainy the photos will be. Even though the stars will show movement with the 500 Rule, you will capture substantially more light.
I personally use the 300 Rule. I find it to be the best compromise between sharp stars and capturing enough light. You can decide for yourself which Rule looks best. If you are using a Crop Sensor camera, you may want to stick with the 500 Rule so that you can have less grain in your images.
A Star Tracker is a special device that moves your camera at the same speed as the Earth's rotation. This is by far the most effective way to capture more light and detail in your Milky Way photos. The best part is, you can use a lens that doesn't open to f/2.8 or a camera that doesn't perform well at high ISO's and still get a clean Milky Way photo!
There are many different options for star trackers, but I personally use the iOptron Skytracker Pro and I recently upgraded to the iOptron SkyGuider Pro. Honestly, I would recommend purchasing a device like this over an expensive new lens! The image below was taken using the SkyTracker in Colorado. I was able to shoot a 4 minute exposure and capture a lot more light and detail in the night sky!
Click here to read my full Star Tracker tutorial, which includes a buying guide, step-by-step instructions, a video tutorial of the SkyTracker Pro, and a Post-Processing Tutorial!
Using a Star Tracker is relatively simple, yet it can be a pain to setup correctly. First, you need to align the device with Polaris, the North Star. This can be surprisingly difficult! If you are using the iOptron Skytracker Pro, it has a built-in base that helps with this process. You will need to know your latitude though. I recommend TPE (The Photographer's Ephemeris) app. It will not only show your latitude in the upper right corner, but it gives you a wealth of necessary information including: sunrise / sunset times, twilight times, and moon rise/set times. This information is invaluable for Milky Way photography. Once you know your latitude, you can adjust the Star Tracker's base to match. Now your star tracker should be pointed up at the correct altitude.
Your next goal is to make sure the star tracker is pointing North and directly at the North Star. If you are unfamiliar with the night sky, this will undoubtedly be somewhat complicated. I always look for the Big Dipper first. Then I take the corner star in the Big Dipper, and draw a straight line across the sky. This line should point right to the North Star. The North Star should be brighter than any other stars nearby. Remember though, the Big Dipper will rotate counter-clockwise around the North Star during the night. Depending on the season, the Big Dipper may be "upside down". Hopefully the image below illustrates this technique clearly.
Finding the North Star
Once you have the North Star located, look through the Sky Tracker's scope and check if the North Star is visible through it. This step always gave me the most trouble. Frankly, I didn't realize I could adjust the focus of the polar scope. I've since focused it properly to my eye and the stars are sharp. Before I learned this, I would just roughly eyeball it and use the scope kind-of like a gun sight. This seemed to work well enough for wide angle photos, as well as 100mm photos at 60 seconds.
Next, you need to make sure the star tracker is level. The Skytracker Pro linked above has a built in bubble-level that helps. If you happen to find yourself shooting on pavement, you're in luck! However, if you are in the wilderness, you will need to adjust the tripod legs so that the star tracker base is perfectly level. This can be a tedious process.
Finally, you need to balance the weight of your gear on the Star Tracker. If you are using a big telephoto lens, you will need to add counterweights. However, if you only have a small camera and lens, a counterweight is unnecessary. Click here to see the SkyGuider Pro's counterweight system.
Your accuracy with these steps will determine how long your Shutter Speed can be before star trails become apparent. Keep in mind, the longer the focal length, the more precise you will need to be with your alignment. At 14mm, as long as you're fairly close you should be able to shoot for at least 2 minutes without star trails. At 200mm though, if you are slightly off-alignment, you will see star trails after 20 seconds. If you are using a 200mm lens, you will also likely need to use a counterweight. The counterweight is needed to balance everything properly, otherwise the mount will not rotate properly and your stars will be blurry.
It's important to remember not to touch your tripod once you have a good alignment. Otherwise, you will have to go through the alignment process again. The first time I used my star tracker, it took me at least 30 minutes to get a good alignment. After using the device about a dozen times though, I was able to get good alignments within minutes.
There is one major downside to using a star tracker though. Since the tracker is moving the camera to follow the stars, the foreground will blur out! This poses a dilemma. We can either have a sharp foreground or sharp stars. The only way around this is to take 2 photos and blend them in post-processing. Thankfully this is a relatively easy process in Photoshop. However, sometimes the horizon can be very tricky to blend between the two photos.
I recommend using Luminosity Masks to blend your 2 exposures together. This process is actually pretty easy once you are familiar with Photoshop. First, you should download the free Easy Panel by Jimmy McIntyre. Once you have that installed into Photoshop, you're ready to follow along with the tutorial below.
Ultimately, a star tracker is the best way to capture high-quality Milky Way photos without breaking the bank on a new lens! After dealing with ugly, grainy Milky Way photos for 3 years, I wish I had bought one sooner!
This ugly purple grain that can ruin an otherwise good photo. Every camera has different amounts of grain and Amp Glow; some newer cameras have very effective sensor designs that can entirely remove this problem at a hardware level. For more information, read this article by Roger Clark.
This purple noise is mainly caused by sensor heat and lack of light. Therefore, you will likely notice this problem on warm nights. Using Live View will increase the sensor temperature the most. Therefore, it's best to minimize Live View usage, if possible. If your camera has a flip-out or rotating screen, move it away from the camera body. This will help to keep the camera a bit cooler. The ambient air temperature will also have an affect on the sensor's temperature. If it's a warm night, the sensor will take longer to cool down.
Click here for more information on keeping your sensor cool at night, and how a hot sensor can cause more noise
The amount of light captured will also have a major effect on the level of amp glow in your photos. Basically, the sensor needs to collect photons, which provide information for the final image. If the camera doesn't capture a lot of photons, the underlying sensor noise and heat will be visible in the photo. Imagine a canvas and a painter. If the painter doesn't put enough paint in the corners, the canvas will still be visible. Same thing here, but with light instead of paint.
The Before/After below shows a 15 second photo at ISO 12800, vs a 4 minute long photo at ISO 800. By capturing 16 times more light, the After image shows a massive improvement. Next time you head out, try taking a 4 minute long photo, instead of a 20 or 30 second image. Of course, you will need to blend in a sky exposure.
I've recently discovered a bad "glitch" when using Long Exposure Noise Reduction at night. On my Nikon D750, LENR causes the stars to have really weird colors, including green, magenta, and cyan. After a recent series of tests, I've confirmed this problem is a direct result of using LENR in-camera. Therefore, I would recommend everyone try this test on your own images ASAP.
Set your camera to ISO 3200, f/4, 30 seconds. Take one image with LENR turned OFF, and another with it turned ON. Zoom in at least 100% on your computer and see if you notice the same issue as below:
Once LENR is turned on in your camera's menu, any Long Exposure you take (usually 1 second or longer) will engage the Noise Reduction. The camera takes another exposure of equal length, a dark frame. Then, the camera compares the Dark Frame with the original photo, removes any Hot Pixels and Amp Glow, and saves a final RAW or JPEG photo. Keep in mind, the camera will be unusable during the LENR stage. If you take a 4 minute exposure, you will need to wait another 4 minutes for the camera to capture the Dark Frame and then process the final image. The image below shows just how well LENR works at removing hot pixels.
I would only recommend using LENR when photographing your landscapes / foregrounds at night. This is the easiest and most effective way of removing hot pixels, if you don't want to remove them manually in Photoshop. However, be sure to turn LENR OFF when photographing the Milky Way or sky, as it will likely cause the weird color shift seen above.
As we saw above, Hot Pixels will look like bright, multi-colored dots in your image. The warmer it is outside, the more hot pixels you will see in your image. Likewise, if you take photos longer than 30 seconds, the sensor will usually start to produce a lot of hot pixels. If you forget to enable Long Exposure Noise Reduction, and have an awesome image plagued by hot pixels, there are ways to fix it.
If you remembered to take a Dark Frame while you were out shooting, you can try the Photoshop Subtract method, detailed in the video below. The best way to remove hot pixels in post-processing is the Dust and Scratches Filter in Photoshop. This works wonders on hot pixels, but it can be tricky to get right. The video below covers the process in detail.
In my experience, Long Exposure Noise Reduction is the easiest and best method to removing Hot Pixels. However, it does not seem to do much for Amp Glow; so be sure to take a Dark Frame while you are shooting and use the Photoshop Subtract method to reduce Amp Glow.
For more information on removing Hot Pixels, watch the video below.
In order to reduce noise and increase detail in your Milky Way images, it is essential to do Photo Stacking. This process enables you to take multiple photos and have Photoshop find and remove grain. This is my favorite method for creating noise-free Milky Way photos. If you are familiar with taking star trail photos, it's the same process. You need to capture 10+ images, one after the other, and blend them together. This process can be complicated when using a wide angle lens however.
Since the stars are moving in each frame, Photoshop will have a tough time aligning images taken with a wide angle lens (14mm). Photoshop can never properly align images taken with my Rokinon 14mm due to the wide angle distortion. I've had the best alignment success when using my Sigma 35mm lens. There is a free program that can successfully blend wide-angle photos to reduce noise, it's called Sequator. I recommend using this application for photo stacking not only wide angle images, but nebula and galaxy photos as well! You can watch my tutorial below.
You will need Photoshop CC or CS6 Extended, RAW capabilities, and an Intervalometer to successfully capture these images for photo stacking.
With those settings dialed in, take a test shot and verify everything is sharp. Now, use your camera's built in intervalometer (or use external device) and set it for anywhere between 10 to 50+ exposures. The more images you have, the less grainy the final image will be. Set the Interval to either 1 or 2 seconds longer than your shutter speed. (8 Second interval for 6 second shutter speed) If you've done Star Trails before, using the Intervalometer, it's the same process.
This method takes a bit more work, but it can be very beneficial for noise reduction. At the very least, you can use this method to remove the noise from your foreground. Combine this with a Dark Frame subtraction and your images will be looking good! No Amp Glow, no hot pixels, and minimal noise!
Milky Way photos straight out of the camera are very boring, in my opinion. To fully bring out the detail and color takes an extensive knowledge of Adobe Camera RAW and Photoshop.
You can watch a full-length Milky Way editing tutorial over on my YouTube page.
This video covers my personal Nebulosity workflow. The main goal of this process is to emphasize the Milky Way and nebulae in the night sky.