The Milky Way is a fantastic target for photographers who want to try their hand at astrophotography. However, getting that perfect shot can be tricky! If you need some tips or just want to learn more about capturing a stunning photo of the Milky Way, this article is for you. Keep reading to discover ten things you should know about Milky Way photography!
1. What Does the Milky Way Look Like and How Do You Locate It?
Under the right conditions, the Milky Way looks like a cloudy band of stars with a light gray backdrop. It won't appear as bright or colorful as it does in photographs because our natural night vision is primarily black and white. The rods, one of two types of cells in the outermost layer of our retina (the back of your eye), are more sensitive to luminance than the cone cells, which allow us to perceive color. So, even under ideal conditions, the Milky Way appears washed out and much less colorful than you might expect.
The easiest way to locate the Milky Way is by using a celestial simulator like Star Walk 2 or Stellarium. These apps provide a real-time view of numerous celestial objects, including the Milky Way. If you want to locate the Milky Way without an app, you’ll need to know when and where it will be visible. This is relatively simple, but it helps to have a diagram, as Earth, the solar system, and the Milky Way are all moving at different speeds and directions. If you want to explore these mechanics in detail, check out our article covering How to View the Milky Way.
2. What are the Best Conditions for Milky Way Photography?
The best conditions for any type of astrophotography are clear, dark skies with the Moon below the horizon. This holds true regardless of the equipment or style of image. The two most important sky conditions to consider are cloud cover and light pollution:
- While clouds near the horizon can occasionally make for a nice foreground, they can easily ruin a Milky Way image. As they move across the sky, clouds reflect surface light and block star light. This will cause long exposure images to appear washed out, hazy, and smeared. While it's possible to edit clouds out of an image during the post-processing stage, it is better to avoid imaging on cloudy nights.
- The light produced by a bright city can further impact your ability to image the Milky Way. With that said, as long as you set your expectations right, it is possible to capture an image of the Milky Way in moderately light-polluted skies. However, if you want to capture a stunning image of the Milky Way, you'll need to find a dark sky location.
For up-to-date forecasts on local sky conditions, check out ClearDarkSky.com.
3. How Do You Find Dark Sky Locations?
Imaging under dark skies is incredibly rewarding and fun, but how do you find a good dark sky location? The easiest way is by using a light pollution map. These maps use data from satellite imagery and the nine-step Bortle scale to spatially represent the effects of light pollution. The Bortle scale ranges from 1 (little or no light pollution) to 9 (most light-polluted). If you want to learn more about light pollution and the Bortle Scale, check out our in depth exploration of The Effects of Light Pollution!
Once you've reviewed a light pollution map, look for a suitable location that falls within the lower end of the Bortle scale (1-4). Keep in mind that when choosing an imaging location, you'll need to consider the direction of any nearby sources of light pollution. For instance, if you’re in a dark sky area but there’s a bright city between you and the Milky Way, the city lights might produce a "light gradient" in your images.
Alternatively, you can look for a dark sky park. Check out our Ultimate Guide to Dark Sky Parks to learn more about the various dark sky sites across the United States.
4. Can You Take a Photograph of the Milky Way During a Full Moon?
While it is technically possible, imaging the Milky Way during a full moon is needlessly difficult and time-consuming. This is due to “skyglow,” which occurs when light interacts with various molecules and particles in our atmosphere. Since the lunar surface reflects a great deal of sunlight, it causes the atmosphere to glow, ultimately reducing overall transparency. Moreover, the light reflected from the Moon will cause long exposure images to be overexposed.
Ideally, you should aim to capture the Milky Way when the Moon is near or below the horizon to get the best results. If you want to avoid planning your Milky Way imaging session during the full moon phase, check out our interactive guide on Predicting the Phases of the Moon!
5. What is the Best Lens for Milky Way Photography?
The best lens for Milky Way Photography depends on the type of image you intend to capture. If you want to capture a wide-field, landscape-style image of the Milky Way, you’ll likely want a "fast" wide angle lens. Typically, any lens with a focal length less than 35 mm is considered wide, but 18 mm to 14 mm lenses are ideal, as they allow you to capture more of the Milky Way in a single frame. For a lens to be considered “fast,” it needs a wide maximum aperture, so you’ll want to look for a lens with a low focal ratio (generally below f/3.5). A fast lens will allow light to reach the sensor in a shorter amount of time, which is especially beneficial if you are not using a tracking mount to capture the Milky Way. Alternatively, if you want to capture a small area of the Milky Way or explore the beautiful nebulae near the galactic core, you can use a lens or telescope with a longer focal length.
Regardless of the style of image you aim to capture, using a prime lens will produce better results. Unlike a telephoto lens (also known as a zoom lens), prime lenses are fixed at a specific focal length. The benefit of shooting with a prime lens is that they are often crafted higher quality glass, which is less susceptible chromatic aberration and color fringing. However, it's important to note that you can still capture stunning images of the Milky Way with a telephoto lens, so long as it is right focal length.
6. What is the Best Camera for Milky Way Photography?
Choosing the best camera for Milky Way photography is tricky. With new models being released every year, and the constant innovation of sensor technology, finding a camera that truly holds the title of "best camera for Milky Way photography" is nearly impossible. More importantly, you do not need the best or newest camera on the market to capture stunning Milky Way images. Instead, it’s best to consider which camera best fits your needs and imaging style. Below, you'll find a few general factors to consider when buying a camera for Milky Way photography:
- Sensor: For Milky Way photography, the size and resolution of the camera sensor is important to consider. Due to their larger sensor and a wider field of view, full frame cameras can make it much easier to frame the Milky Way. They also offer a wider range of lens options and can make full use of the light gathering power of super-wide "fast" lenes. You should also consider resolution, as you'll want to capture as much detail as possible. You don't need the highest resolution camera available, but generally, a higher mega-pixel sensor will give you the most control over the quality of your final image. Just keep in mind that more pixels equals more data, and more data means bigger files. So, it’s best to pair your camera with a memory card with a fast write speed.
- Specs: Noise, or the random signal capture by your camera’s sensor, is detrimental to quality of your Milky Way image. While there are many ways to reduce or remove noise from your final images, it can come at the cost of details and contrast. So, you’ll want to look for a camera that features a wide ISO range and good low-light performance. Brands like Sony, Nikon, and Canon have plenty of great options that meet these criteria. However, it’s important to consider the price and availability of lens options, as having the wrong focal length lens will limit your ability to image the Milky Way.
- Type of Camera: DSLR cameras are versatile but have limitations for astrophotography. For example, the movement of the reflex mirror can cause blurring during long exposures, and the optical viewfinder can make it difficult to find the ideal focus with looking at dim objects. On the other hand, a mirrorless camera has fewer moving parts and a live view mode that makes it much easier to focus and frame an image. Both types of cameras will allow you to capture beautiful images of the Milky Way, but mirrorless models may offer less resistance for some.
- Use:If you only want to capture images of the Milky Way or other deep sky objects, you should consider purchasing a modified DSLR or mirrorless camera. These cameras have been altered to capture a wider range of light, allowing them to reveal hidden features in the Milky Way not naturally visible to the human eye.
Another option to consider is purchasing a dedicated astrophotography camera. Typically, these cameras are used with a telescope for deep sky or planetary imaging, but some models can be adapted to work with a wide-angle camera lens. While not nearly as convenient as the prior options, dedicated astrophotography cameras offer a wider range of functionalities than traditional cameras, and there is a large catalog of models from which to choose. There are also models with monochrome sensors and onboard cooling that reduce or eliminate image noise, and some models can make use of specialized filters that separate and block specific wavelengths of light. Moreover, these cameras work with software applications like SharpCap, which offer precise control over capture settings and file management.
7. What are the Best Settings for Milky Way photography?
The best settings for capturing the Milky Way depend on your camera, imaging conditions, and equipment.
- Modern cameras with advanced sensors are more sensitive and perform better in low light, allowing you to increase the ISO and decrease the exposure time. However, if you’re using a tracking mount, like the Star Adventurer 2i Pro, you'll want to aim for longer exposures with a lower ISO.
- Imaging conditions also play a role in the best settings for imaging the Milky Way. Dark, clear skies offer the most flexibility. However, in light-polluted areas or when the Moon is above the horizon, you’ll need to determine how long you can expose the sensor without overexposing the image, even with a tracking mount.
- The only constant setting for Milky Way photography is the f/stop or aperture, which should always be set to the widest aperture available (lowest f/stop) to optimize the amount of light reaching the sensor.
8. Can You Image the Milky Way with an APS-C Camera?
Yes, you can easily capture a stunning image of the Milky Way with an APS-C camera! However, your field of view will be narrower when compared to a full-frame camera using a lens with the same focal length. This is because APS-C cameras have smaller sensors.
APS-C cameras often come with "kit lenses" designed specifically for their smaller sensors. Nevertheless, you can certainly use a lens designed for a full frame camera on an APS-C camera. This is because both types of lenses share the same standard for focal length; however, APS-C cameras use smaller sensors and cannot utilize the full width of the image circle produced by a full frame lens.
This is why APS-C cameras have a narrower field of view and have a "crop factor" (usually 1.5 or 1.6). The crop factor allows you to find the focal length of a lens with a comparable field of view. Simply multiply the crop factor by the focal length of the lens you intend to use, and the result will be the focal length of a lens with a comparable field of view (when used on a full frame camera). For example, an 18 mm lens on an APS-C camera with a crop factor of 1.5 is equivalent to a 27 mm lens on a full-frame camera. This does not impact the quality of your Milky Way images; it simply limits how much of the Milky Way you can frame in a single image.
9. Can You Image the Milky Way with a Smartphone?
Modern smartphones have small lenses and even smaller sensors, which can limit their ability to take good photos of the night sky. To compensate for these limitations, many smartphones have multiple imaging sensors and use complex software to improve image quality. If your smartphone allows you to capture long exposure images, you may be able to photograph the Milky Way. Additionally, if your smartphone has the ability to save and edit RAW files, you can further improve the quality of your Milky Way photos.
With that said, smartphones are not designed for astrophotography. So, even if you can capture an image of the Milky Way, you might notice star trailing and other unwanted image artifacts. Despite these challenges, with the right settings and a bit of patience, you can capture an impressive image of the Milky Way with a smartphone!
10. What is the Rule of 500?
To capture an image of the Milky Way, you’ll need to take long exposure photos. This means keeping the camera’s shutter open for an extended period to gather enough light from the stars. However, due to the rotational speed of the Earth, stars will appear to streak across the sky if you’re not using a tracking mount. To avoid this, you need to limit the exposure time.
To figure out the maximum exposure time before star trails appear, you can use the Rule of 500. This rule is simple; just divide 500 by the focal length of your lens, and the result will be the maximum length of exposure. For example, if you’re using an 18 mm lens, divide 500 by 18, which gives you 27. This means you can expose each frame for up to 27 seconds before star trailing becomes noticeable.
If you’re using a camera with a crop sensor (APS-C), you’ll need to account for the crop factor. Be sure to multiply the focal length of your lens by the crop factor (usually 1.5 or 1.6) before dividing by 500.
Learn More
Interested in learning more about astronomy, astrophotography, and more? Check out our Astronomy Hub!
Glossary
Aperture
The camera aperture is an adjustable opening within a camera lens that controls the amount and direction of light that reaches the imaging sensor or film. Wider apertures have a narrow depth of field, making the background or foreground appear blurry. Narrow apertures have a wider depth of field, bringing more of the image into focus.
Astrophotography
This refers to photography of astronomical bodies and phenomena. Astrophotography is not new, for example the popular T threading still used today harkens from Tamron’s T-mount developed for their 35 mm cameras - however it has seen a notable increase in popularity with improvements in cameras, mounts, filters, and software making astrophotography much more accessible. This is not limited to celestial bodies such as nebulae, planets, or galaxies either, as solar imaging is now more within the reach of the average consumer than ever before.
Background
A background is the part of a scene that falls behind the subject, and is furthest away from the observer.
DSLR
DSLR stands for digital single lens reflex and it is a type of digital camera designed to integrate the mechanics of analogue SLR cameras with a digital imaging sensor. These cameras feature interchangeable lenses, a reflex mirror that allows a user to see through the camera lens via the viewfinder, and a digital imaging sensor that converts light into a digital file that can be stored on a memory card.
Foreground
A foreground is the part of a scene that comes between the subject and the observer.
Galactic Core
The galactic core, also known as the galactic nucleus, is the luminous center point of a ecliptic and spiral galaxies. In our galaxy, the galactic core is home to a supermassive black hole know as Sagittarius A.
Image Masking
Image masking refers to a wide range of processing techniques used to isolate and alter specific areas of an image, and layer multiple images atop one another. It can be achieved digitally with processing programs such as photoshop, or it can be done altering physical images and film negatives.
Image Stacking
A method used to bring out what would otherwise be faint or invisible detail and contrast in an astrophotography image. When imaging a target, the longer an exposure is, generally the more faint detail will become visible. However as exposure time becomes longer several complications emerge - motion blur due to compounding small deviations or errors in tracking, increased sensor noise and glow, and overexposure of the bright areas of an image. Stacking mitigates these issues by combining a number of shorter exposure images, commonly called sub exposures, sub frames, or simply “subs”, into one image that effectively has a longer exposure time. The stacking process can further improve the resulting image with the use of calibration frames that help identify and compensate for visual artifacts introduced by the optics or sensor itself.
ISO
ISO is an acronym for the International Organization for Standardization. This organization works to create standards for various technologies, practices, and methodologies. In the case of imaging sensors, ISO is a numerical value assigned to the sensor's light gathering sensitivity. Higher ISO values collect more light and a faster speed, while lower ISO values collect less light and a slower speed.
JPEG
A JPEG image is a commonly used file type that is pre-processed and compressed. Due to the smaller file size, JPEGs can be efficiently stored and easily shared online. However, the compression significantly alters the image, limiting the range of processing options.
Lunar Cycle
A lunar cycle refers to the 29.5 day orbital period of the Moon around our planet, in which the Moon transitions through all 8 of its main phases.
Milky Way
The Milky Way is the name of the galaxy that hosts our solar system. Named for its bright milky appearance in the night sky, the Milky Way is home to countless stars, nebulae, and a even a few supermassive black holes. It estimated to be over 13 billion years old, and it would take over 100,000 light years to travel from one side to the other.
Mirrorless Camera
A mirrorless camera is a type of digital camera designed to maintain the functionality of DSLRs with less mechanical parts. Like DSLRs, they feature interchangeable lenses, however, they do not use an optical viewfinder or reflex mirror. The parsimonious design of mirrorless cameras makes them lighter, slimmer, and quieter than DSLRs and allow for more versatile imaging features.
PNG
A PNG image is a commonly used file format that achieves a reduction in file size without a loss in image quality. This file type is often used to share images that would otherwise be altered by the compression necessary for online usage.
Polar Alignment
Polar alignment is the process of aligning a telescope mount’s polar axis with the Earth’s axis of rotation. By having these two axes parallel to one another, precise counteraction of the Earth’s rotation can then be achieved. While a typical process of equatorial mounts that have three inherent axes of rotation, a similar effect can also be achieved by utilizing an equatorial wedge with two-axis alt-azimuth mounts.
RAW File
A RAW image file is an uncompressed copy of the information received by a digital imaging sensor. Often referred to as digital negatives, RAW files are minimally processed, allowing for a wider range of processing options.
Shutter Speed
Shutter speed refers to the speed it takes the mechanical or electrical shutter of a camera to open and close. By adjusting the shutter speed of a camera, a photographer can control the exposure of an image.
Tracking
As the Earth is continuously spinning and in motion, the location of a celestial object in the sky moves over the course of a night. This becomes apparent during observation as a target moves out of view, and particularly observable in images as stars and objects quickly become a blur as exposure time and focal length increases. To compensate for this, computerized mounts and smart telescopes employ tracking techniques to keep the target centered in the optics. Depending on the motion style of the mount, the resulting image can vary. Alt-Az motion, popular in smart telescopes, keeps the object centered but can not compensate for its “spin” without what is known as a wedge. Accordingly these images lose information on the edges of the frame as they rotate out of view, leading to ever smaller, circular, images as time spent imaging increases.
