Updated: Apr 7
Learn how to shoot the Milky Way for social media use the easy way.
We woke at 2 am to get up on Trail Ridge Road before 3 am. Sometime in the past few weeks, a comet named NEOWISE was spotted and it's been making waves among photographers. Its large size and proximity to the horizon has made for some really outstanding shots, and we finally found the time to be out in the early morning hours to get up and see it.
Of course when we arrived and for the entirety of the time we had on the tundra before sunrise, we had clouds to the east that blocked all of our view of the comet. But since we had made the trip, it was a useful time for instruction and practice in astrophotography since my friend had never tried it before.
Among professionals, it's most popular to work on stacking multiple images to create one image that really showcases the depth and color of the Milky Way. Some people use dozens, others use hundreds or thousands of individual images with software like Photoshop or Deep Sky Stacker to build a single image. Stacking can yield stellar results, but most people just getting into the world of astrophotography have neither the time nor inclination to learn a new set of software tricks.
Instead, there are ways you can do excellent astrophotography in a single frame if you're just looking to put together a portfolio for social media.
The key to understanding image publishing on social media sites like Facebook, Instagram, and LinkedIn is that these sites massively compress your photos when you upload them to save space on their servers.
A common struggle is something along the lines of, "I bought an [expensive camera] and my photos look great when I'm done editing them, but they look awful when I upload them! Plz help, TIA!"
When you are working with today's high-resolution cameras like the Nikon D850, Sony A7RIV, Canon 5DSR, etc. you're creating huge files that contain millions of data points. All that data doesn't go away when you export from RAW to JPEG, particularly when you are only compressing some color data instead of compressing the actual file resolution. For example, my Nikon Z7 produces RAW still image files that are usually around 100 MB each. After editing and JPEG compression, some of them still end up being 50 MB or above at full 45 MP resolution.
One thing to keep in mind is that when you upload a 45 megapixel image on Facebook or Instagram, literally nobody in the entire world will ever see it at 45 megapixels, even if Facebook does allow ultra high resolution image display given your display's ability to show it. Simply put, almost nobody has an 8K TV, monitor, tablet, or phone screen. Since the majority of internet traffic is mobile and most mobile devices actually display images and videos at a resolution lower than their advertised pixel count, you can safely assume that most people will be viewing your images and videos at somewhere around 2000 - 3000 pixels on the long edge at most.
Additionally, the human eye actually cannot detect most of the detail in today's ultra high resolution video and photos without a serious display size and a considerable distance to the display. Electronic manufacturers know this, which is why 1080P video still looks great on your 55 inch 4K TV despite being well below your screen's native resolution. Once again, consider that most internet traffic today is mobile. Most people will see your images and videos on a 5 to 6 inch screen. Your eye won't see almost any real difference on that tiny screen between 720P, 1080P, and 4K or 8K content.
If Instagram is your jam, you really don't want to upload ultra high resolution images. No matter what you create, Instagram only displays them at 1080 x 1350 (as of July 2020). In order to do that, it compresses the color and contrast out of your image and then allows you to bring some of it back in the editing window. You can actually see it happen in between selecting your file and then seeing the editing window. When you start with a huge file, Instagram and Facebook need to compress it a huge amount in order to meet the platform's compression specs. For all the work you do in making every pixel perfect, a lot will be lost when you leave it up to these platforms to make your image work on their platform.
You simply are working too hard to impress people with resolution they will never, ever see or appreciate. I say all this to preempt the pixel-peeping "pros" crying about star trails appearing in most single-frame astrophotography images. It's true, but it's not relevant or even noticed.
Unless you're planning to create physical prints of these images, there are certain details you can actually overlook and still come out with some great results from any interchangeable lens (DSLR, Mirrorless, Micro 4/3, etc.) camera.
Since most people are working with APS-C or Full-Frame DSLR or Mirrorless cameras, I'll speak to my experience with those here. Micro 4/3 is beginning to disappear, and I suspect will be completely gone in a couple of years with the onslaught of mainstream APS-C mirrorless cameras, lenses, and accessories.
I began shooting astrophotography with a Nikon D3300. Among interchangeable lens cameras, this is one of the most basic and affordable options out there. I bought one five years ago for $300 on eBay, and I would believe that they would be even cheaper now with two generations (D3400 and D3500) surpassing it at still-affordable prices.
Many people shoot at ultra-high ISOs like 10,000 or 25,600, but you really don't need to. For most cameras, you can shoot at ISO 500-2000 with an exposure time of 8-10 seconds and an aperture of around 1.8-2.8 and create a decent image for social media use in a single frame. That means that you can do this on a very tight equipment budget with a 35mm 1.8/f lens on an APS-C camera or a 50mm 1.8/f lens on a full-frame camera, each around or less than $200.
There are two main enemies when you're shooting astrophotography on a still tripod; exposure time and ISO-related image noise. Unless you have a sky tracking device of some kind, you'll need to keep your exposure time below about 13 seconds.
At around 13 seconds, you'll begin to see macro-level star trails. That is, the 'smear' of the star motion in the sky moving relative to your camera's still position. Those macro-level star trails will still appear when you export to a low-resolution image for social media. Micro-level star trails are visible on virtually any image that is shot on a still tripod, and there's not a lot you can do about it except stack tons of photos or get a tracking device. Fortunately, micro-level star trails are easy to hide on low-resolution photos for social media use. You can avoid some of these micro and macro-level star trails by boosting your ISO, but you will see a noticeable uptick in color noise above about 2000. That will make your editing more difficult to keep your details sharp when you try to denoise it.
Because you'll want to export your images out of Adobe Lightroom or Photoshop/Camera RAW at 2000px on the long edge for social media use to avoid platform compression, most of these micro-level star trails will disappear after a little sharpening and resolution down scaling.
Milky Way for beginners equipment and settings checklist:
Locate the Milky Way in the darkest available sky. The best time to shoot is during the summer. You will see the Milky Way with the naked eye as a thick band of stars generally running north to south, with the southern end being the most photogenic with the bright core exposure. Try to find an area with no major cities directly south of you.
2.8/f or faster lens. For best results, try a 1.8/f or faster lens at 35mm or less.
ISO 2000 or less
Ensure your lens focus is at infinity or the sharpest point for infinite distance objects (some people say certain brands or manufacturers actually focus better slightly off the official infinity mark).
Make sure Autofocus is turned off or you do not activate your back-button focus after setting your preferred infinity focus setting.
Exposure time of 13 seconds or less to avoid macro-level star trails.
Export your finished edit as a JPEG at 2000px on the long edge to minimize social media platform compression effects on your photos for Instagram, Facebook, and LinkedIn while maximizing quality for 80%+ of your viewers on mobile, tablet, laptop, or desktop users.
These settings will give you usable images for your social media portfolio in only a single frame. No need to composite, stack, or take hundreds of images or learn new software. Be creative with the photos you take. When you're doing long-exposure photography, there are lots of neat things you can do while shooting to create truly unique images. Remember that the stars or the Milky Way may be the perfect background setting for something interesting in the foreground.
When you want to take it a step further and create truly stunning and sharp images suitable for large-scale printing, there are plenty of tutorials on blogs and Youtube to get you familiar with shooting and stacking images, purchasing and using sky tracking devices, and all the little details necessary to go full pro with equipment, settings, and print media choices.