How to Shoot Deep Sky Photography
There are very few things that are as awe-inspiring and as magical as deep sky photography. Not even looking through a telescope can compare to the images that deep sky photos can capture. This is because a camera can record even more light than we can comprehend with our eyes—which allows us to get the vibrant colors and contrasts that deep sky photos are known for.
Deep sky photography is all about capturing beautiful deep-sky objects in the night sky. Also known as astrophotography, this is a very unique type of photo-taking and is a term to simply describe using a DSLR camera and a telescope to capture up-close view of objects in space.
This is a really fun type of photography and is also something that takes a slightly different approach than your standard point and shoot photos. It is also one of the most detailed and tricky types of photography, and it is known to test the patience of even the most skilled of photographers.
The best way to really master this type of photography is to start learning the basics and tweak this approach as you try to learn on-the-go. This is why we have created a beginner’s guide to shooting deep sky photography to help get you started.
Collecting the Right Deep Sky Photography Gear
Before you start taking these types of photos, you need to make sure you have the right gear to shoot these photos.
Camera- Even a beginner’s camera will work for capturing deep sky objects, you just need a DSLR with a 30-second exposure option. Of course, the better the camera, the better off you will be, but your entry-level camera will work as well.
Tripod- A tripod will be a necessary addition to your arsenal of products for your deep sky photos. With tripods, it is important to remember that the sturdier the better with these accessories—so the big, older, robust tripod will do just fine.
Lens- A wide-angle camera lens is another necessity when shooting this type of photography. One of the most popular lenses out there right now for astrophotography is the Rokinon 14 mm F/2.8. This is a great lens even for beginners because it has a faster aperture and comes at a budget-friendly price tag.
Telescope- If you are less-interested in wide-angled shots that capture everything in the sky, and more interested in capturing far away images close up, you need to pay close attention to the telescope that you choose. There are specialty astrophotography telescopes available—just made sure that you have a t-ring adapter to connect the DSLR body of your camera to this telescope.
Tracking Mount- This is one of the most important pieces of gear for any deep sky photography session—it is also the piece that most people forget. A high-quality mount that is polar-aligned can handle your telescope, camera and accessories. If you want longer exposures (and you should with this type of photography) choose one with auto guiding that allows you to take exposures of 10 minutes or more.
How to Take Deep Sky Images With a DSLR and Telescope
Now that you have all of the appropriate gear, it is time to actually start shooting your deep sky images. For most beginners the most difficult part of shooting is implementing the telescope into your photographs.
When taking deep sky photography, you will need to take several long exposures. This will help you capture enough light from a dim object out in space to still show color and details. Here are some other things you will need to do when shooting these types of photos.
The Polar Alignment
In order to get clear images with this type of photography, you will need to make sure your telescope mount is polar-aligned. This ensures that your telescope mount will turn at the same angle as the rotation of the earth.
Tip: If you are in the Northern hemisphere, you can use the North Star to align your mount.
One of the most unique things about deep sky photography is that the colors from these objects tend to show up as much more bright and colorful than they would be if you were looking at the image through a telescope.
This is because a camera sensor can record more detail and light than our own eyes. This is why tacking is so important as it helps to make sure that the camera and the telescope lock on to the subject, so you can record this light and detail.
The best way to “track” or auto guide is to use a software program called PHD Guiding 2. This program will communicate with the telescope mount and make adjustments to the tracking as-needed.
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M51 – The Whirlpool Galaxy. Located around 23 million light years from Earth, it can be found not far from the Big Dipper. A face-on spiral galaxy, it is about 25-33% the size of the Milky Way. M51 is unique in that it is an excellent example of interacting galaxies. The second galaxy, an elliptical galaxy known as NGC 5195, can be seen below M51 as the bright yellow region. At first glance, the smaller NGC 5195 galaxy appears to be tugging on the arm. However, the Hubble Space Telescope showed that NGC 5195 is actually passing behind the Whirlpool. The small galaxy has been gliding past the Whirlpool for hundreds of millions of years. As NGC 5195 drifts by, its gravitational force creates ripples within the Whirlpool’s pancake-shaped disk. Star-forming regions can be seen in the magenta areas, whereas many of the older stars reside near the yellowish core of M51. I feel like given my setup’s focal length, this was about as much detail as I could resolve in M51, and this was cropped fairly heavily. I’m hoping to get a longer focal length scope (~1600mm instead of 800mm) at some point in the distant future to be able to better resolve better details in these more distant galaxies and nebulae. I shot M51 as my last target for the night and got an hour of good data in before sunrise. Telescope: Orion 8″ f/3.9 Astrograph Mount: Skywatcher EQ6-R Pro Imaging Camera: ZWO ASI 071 MC Pro Coma Corrector: Skywatch Aplanatic CC Guiding: Orion Starshoot Auto Guider Polar Alignment: QHY Polemaster Lights: 12 x 300s = 1 hour of total exposure Gain: 90 Offset: 20 Darks: none Flats: none Bias: none Taken from a Bortle 1 zone in Death Valley NP, CA Stacked in DeepSkyStacker Adjusted levels & curves in Photoshop until I got a reasonably contrasty image Used Gradient Xterminator plugin to eliminate gradients and vignetting Processed using Astronomy Tools actions in Photoshop, specifically: – Increase Star Color – Select Brighter Stars (which were then masked and shrunken with Levels) – Space Noise Reduction Final touches made in Lightroom, including color enhancements and range masking to adjust saturation levels and bring out more detail.
If you want to really capture those sharp images that so many people love with deep-sky photography, then you need to make sure that your subject is properly exposed. It is important that you don’t overexpose your shot as the extreme brightness of the sky will cause the image to look blown out.
When shooting with a standard camera, you will want to make sure you are using a piece of equipment that can shoot long exposures at high ISO settings. There are also Astro-Modified cameras that are much more sensitive than unmodified cameras. These will allow shorter exposure times for better, cleaner results.
You want to get a tight focus with your camera through your telescope when shooting deep-sky photographs. If you have BackyardEOS, you can use the FWHM method that is built-in to the program.
Another popular option is to use the live view function right on your camera. Just turn your camera’s ISO all the way up to the maximum until you see at least one bright, but out-of-focus star. Then, use the 10x zoom to manually rotate the focus until the star is as small as possible—this is a great trick to getting that focus you are looking for.
Tips on Creating Jaw-Dropping Deep-Sky Photographs
Now that you have the basics of deep-sky photography down, it is time to consider a few additional tips and tricks that can help you get the best possible results with your photos.
- Try to find as dark of sky as possible. When shooting night-scapes, you always look for moonlight, but with deep-sky photography, you want things as dark as possible. This means no moonlight and no artificial light.
If you can, try to shoot on New Moon weekends and go to as remote or rural of an area as possible—the end result will be worth the extra effort.
- Consider using LENR. This is an optional tip, but one that many find will help with their end results. LENR, or Long Exposure Noise Reduction. While some people prefer to take dark frames at the end of a session by capping the lens, then subtracting the dark frames in “post-production.”
Try LENR instead. It takes a little longer to get the images, but the end result is much better.
- Try some accessories. There are a lot of accessories that can make things easier when shooting deep sky photography. A remote release is a personal favorite, as it allows you to trigger the exposure without touching the camera. This will lessen your chances of causing vibrations and ruining the clarity of the image when you take the photo.
A dew shield is another great accessory for shooting at night. It will prevent accumulating moisture on cold evenings from impacting your image. It also shields from reflections and dust.
- Use a laser finder to align the scope. Proper scope alignment is essential with deep sky photography, but it is often easier said than done. Attach the laser to the telescope to make it easier to align. While you’re at it, make sure that you use a level (such as a bubble level you would use during construction) to ensure an even and level mount before alignment.
Little tips like these may seem rather minor, but great deep sky photography always comes down to the smallest of details. This is one type of photography that is going to involve a lot of trial and error—but the best thing that you can do is to stick to the basics and keep trying until you find the perfect setting and the perfect night that can lead to the perfect picture.