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Landscape Astrophotography 101: Let’s talk about settings, baby (and…

Okay, so if you’ve been following along you now know how to focus your camera in the dark. You also know WHERE to focus your camera in the dark in order to get maximum depth of field. Now, you’re asking, what are my settings so that I can capture those awesome images of the Milky Way, thus making me an overnight Internet hero?

We’ll get to that. First, let’s talk equipment: You have a DSLR camera, hopefully with live view. You have a wide or ultra-wide lens that is in focus for your shot. You will probably also need some sort of remote trigger for your shutter. You have a tripod.

Even more important than your equipment is your setting (not your camera settings, mind you, but your physical setting): You should have travelled far, far away from the nearest city lights. At least a hundred miles. Trust me on this. You can spend thousands of dollars on equipment, but if you’re not willing to find the darkest places around, your photos of the Milky Way will fail to thrive. Feed your Milky Way photos with total, pitch darkness. This also happens to mean you also need to wait for there to be no moon in the sky.

Wha? No moon? But, you ask, doesn’t that reduce the number of days that I could possibly take these types of photos to just a handful per month? Yep, pretty much. This is just one of those sad facts of life for landscape astrophotographers. It goes hand in hand with the fact that you can spend more on your camera than you did on your car and the camera will still produce noise at high ISOs. It also goes hand in hand with the fact that there are cougars in them thar woods. And they eat at night.

Cougars aside, the moon thing certainly complicates things, doesn’t it? What all good landscape astrophotographers do is study moon phases (no kidding). Look at when the moon rises and sets; do the same with the sun. Keep in mind that both bodies will affect the amount of light in the sky hours before and after they rise or set. Understand the orientation of the Milky Way and how it moves through the sky (more on this later). Understand that if you’re shooting part of the Milky Way that’s oriented west, and west happens to be the same direction as the nearest city, even if it’s 100 miles away, you very well may lose some detail in the Milky Way because of the city’s light pollution dome. Understand that if you wait several hours for the Milky Way to rotate north-northeastish, then you might have to contend with the predawn light of the sun (in the east). There are very few “happy accidents” in landscape astrophotography. The photos you see online are usually the result of a whole lot of research and planning.

Anyway, now that I’ve said my piece about dark skies, let’s review the three settings that we, as photographers, can use to control light: Shutter speed, aperture, and ISO. If we use the rule of 600, we know what our shutter speed is. For those of you who don’t know the rule of 600, it is the result of 600 divided by your focal length, in seconds. (Keep in mind that if you’re shooting on a crop sensor camera that you should be multiplying your focal length by the crop factor—for instance, on a Canon t4i that’s a 1.6x multiplier).

In order to gather as much light as possible, we’re also going to open our aperture up all the way. Later, in another blog, I’ll discuss when it’s appropriate to stop down a bit to sharpen up the image, but for now, let’s just assume we need to go wide open.

So our shutter speed has already been determined. Even our aperture has already been determined. The only other variable left is our ISO. This is really the only factor that you, as the beginner landscape astrophotographer, can control. Everything else is fixed.

So I’ll tell you the ISO setting I use most often: It’s 3200. I find that to be a very usable ISO for my particular camera. It’s a little noisy, but not so noisy that I can’t deal with the noise in post processing. And it’s sensitive enough to do a really good job exposing the Milky Way, allowing it to really light up and for us to see some of its different, subtle hues.

Your own experimentation should guide you to your own “correct” ISO. If you can handle the noise, by all means, go with 6400 or even higher. If you like a cleaner look, lower your ISO.

So there are my settings. But all technical talk aside, the absolute
most important aspect of Milky Way photography is getting to a dark place. If you live in the city (or even near a city) and you try those settings at night, you’ll quickly find out that what you’re really photographing is a whole bunch of yellowish-orangish light emanating from the city itself. It’s depressing, really, but it’s the truth.

In the photo of Crater Lake below, the orangish glow near the horizon is light pollution from Klamath Falls, Oregon, a city of 20,000 residents about 70 miles away from Crater Lake. If you were in doubt about the insidiousness of light pollution, there’s your evidence. Now just imagine how much orange glow a city 10 or 100 times that size emits. Now imagine the city being 35 miles away instead of 75 miles.

The bottom line: You now know the settings, but you have to escape the city lights to make your Milky Way star photography shine. Until next time, photo-friends!

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Focusing in the Dark, Part 2: Warp Speed Ahead…

*A quick note before we begin: I teach these techniques as well as many, many others in my night-sky photography workshops. For more information, check ’em out here: http://www.bencoffmanphotography.com/star-photography-workshops-and-lessons/*

My last blog on focusing in the dark was kind of a primer, so now we’re going to dive into something a little more advanced. So unbuckle your camera bag, extend your tripod legs, and hang on tight—we’re about to dive into (insert echochamber voice) HYPERFOCAL DISTANCES…Distances…distances…distances…

To keep this discussion clear, I’d like to define a couple of terms below.

•Landscape astrophotography: Landscape photography that also features one or more elements of the night sky (stars, shooting stars, the moon, aurora borealis).
•Fast lens: A lens with a particularly wide aperture.
•Fixed focal length lens/prime lens: A lens that doesn’t zoom.
•Wide lens: A lens wider than about 28mm or so.
•Native ISO: The ISO at which your camera was designed to take photos. For Canons, this would be ISO 100.
•Shooting wide open: Opening your lens’s aperture as wide as possible (to its lowest f-stop number)
•Stopping down: Narrowing your lens’s aperture

So by now you have a few tools in your metaphorical tool belt, the last tool added being your ability to focus your camera in the dark. Hopefully, by now, finding your focus this way feels natural. Let’s go ahead and assume at this point that you’re a fairly dedicated landscape astrophotographer, which means that you’ve invested in a wide and fast prime lens. (I know that I haven’t exactly delved into this topic before, but a wide and fast prime lens is a fairly essential tool for the type of landscape astrophotography in which you “freeze” the movement of the stars in the sky.)

Sharpness is a fairly important aspect of photography, particularly in landscapes in which you’re seeking maximum depth of field (ie, you want everything in your image to be in focus). Your photo has to be sharp if you want to print it large (and who wouldn’t want to do that?). Landscape astrophotography is much the same way, except that sharpness is even more important. Why? Because many landscape astrophotos require high ISOs, and noise reduction is a critical part of post-processing. What happens during noise reduction? Well, sharpness is sacrificed in favor of a “cleaner” or more noise-free image.

Whereas a soft photo at a camera’s native ISO can be sharpened to make it more acceptable, sharpening a high-ISO image (like in landscape astrophotography) only adds to the noise in an already noisy image. In short, you don’t want to do it. (I’ll delve more into post-processing techniques for my landscape astrophotography some other time.)

So sharpness is critically important, and that means getting it right in the field since we may not be able to sharpen it up much in post. If you only want the stars for your image to be in focus and don’t care about your foreground, that’s a fairly easy scenario: just focus on the stars. But that’s not exactly landscape astrophotography, is it?

So we’re going to create a make-believe scenario, and in this make-believe scenario, you’ve discovered, while hiking, the most awesome tree ever, miles away from anywhere, and it’s begging you to take its picture beneath the starry night sky. Further, you’ve decided that in order to make the most effective composition, you need for both the tree (with its super cool gnarly trunk and twisted branches) and the stars above to be in focus.

If you use the ol’ landscape photography rule of thumb “focus one-third of the way into your scene,” you might get a little confused—after all, what’s one-third of the way into your scene when the background is millions of miles away? Using this rule, you might find that your stars are in focus, but the Most Awesome Tree Ever is still out of focus. Worse yet, the Most Awesome Tree Ever (henceforth: MATE) might look like it’s in focus on the back of your camera, and you might not notice that the MATE is soft until you zoom in at 100% while you’re post-processing at home the next day. But by then you’ve hiked out of the place where the MATE lived, and the notes you made in your hiking journal are gone because you accidentally lit your hiking journal on fire with your camp stove while you were absentmindedly talking to your buddy about whether you’ll make next month’s front cover of both National Geographic and Outdoor Photographer, or just National Geographic. And now you can’t remember where that tree was, exactly.

So where does that leave us? How can we reliably know for sure that everything in the shot will be in focus when we’re so often fooled by the tiny, awesome images on the backs of our cameras? Hyperfocal distances and depth of field calculators.

In the olden days, this might’ve involved pulling out a rather large chart, turning on your flashlight, and cross-referencing a couple of figures—all in the field. Nowadays, there are smart-phone apps that can give you this info in the field. How awesome is that? Let’s all take a moment to pat ourselves on the back for living in the digital age. Of course, whipping out your phone still involves adding an artificial light to the scene, killing your night vision, and, if you’re out shooting with a buddy, creating a light that may or may not end up in someone else’s photo.

So here’s what I do: Since I shoot my night shots with two different fixed focal length lenses at one of two or three apertures, I simply memorize the hyperfocal distance most applicable to my particular situation.

For instance, if I’m out with my full-frame camera and my 14mm lens, I know that if I shoot wide open (f/2.8), I can focus 8 feet in front of me, and everything from about 4 feet in front of me to INFINITY will be in focus. How I do I know that? Check out this handy hyperfocal distance calculator online. Cherish that link. It’s magic.

So let’s say I’m shooting on my Canon t3i (a crop sensor camera) with my kit lens, which has a maximum aperture of f/3.5. If I’m shooting wide open (at f/3.5), I need to focus about 16 feet in front of me to ensure that everything about 8 feet in front of me to infinity is in focus. This means that as long as I place the MATE (remember the MATE?) at least 8 feet away from me, I’m golden. The tree is in focus, the stars are in focus, life is good, and I won all photography forever.

This, my friends, is the magic of hyperfocal distances. If you want to, you can trust the “infinity” symbol on your lens (if your lens even has an infinity symbol), but be warned: your lens’s focus can change with the ambient temperature (if it was even correct to begin with coming from the manufacturer). In a certain temperature, that infinity symbol might be dead on. In a radically different temperature, you might not be in focus. Why risk it?

Personally, I’ve memorized the applicable hyperfocal distances for two of my lenses. I don’t need apps, and I don’t need charts. And the great thing about these principles is that they translate perfectly well to standard, daylight landscape photography too. The only difference is that, when you stop down to an aperture that isn’t wide open (as you hopefully would when not shooting star photos), you 1) bring the near limit of acceptable sharpness even closer and 2) you probably create an even sharper photo, since not all apertures are equal when it comes to sharpness. But I’ll get more into that second part in another blog post…..

Until next time, may the clouds part and the stars shine on, my friends!

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Night photography 101: Focusing in the dark

Without fail, the first problem that most photographers encounter when trying their hand at low-light or night photography is an inability to focus. After all, they’re used to autofocus, and their gear has likely been doing much of the focus work for the photographer up till now. As a general rule for night photography, I completely forget that my camera and lens can autofocus. I flip the switch to manual, and I don’t look back. There’s something about the endless whirring of a lens’s autofocus hunting that drives me crazy—it’s like a tiny voice from your camera whispering, “Psssst! Hey! This photo’s going to suck!”

So, step 1: I turn off autofocus.

For step 2, I’m going to assume you’re shooting on a DSLR with live view. For those of you on a DSLR without live view, I feel your pain. I did a fair amount of night photography on a first-generation digital Rebel, and it was very, very difficult. But times have changed and cameras have evolved, so I’m guessing that you probably have live view on your camera. If so, turn it on. The LCD on the back of your camera is probably still black, albeit with a few glowing symbols around the display’s periphery.

Next, I’m going to assume you’re using a tripod. After all, it’s only about 100% necessary when shooting at night. (Unless you’re engaging in a form of light painting called “camera painting,” in which you move your camera while shooting stationary lights during a long exposure.) While your camera is securely mounted on its tripod, find an object in the foreground that you think should be in focus. Illuminate this object with your flashlight. Can you now see this object on your LCD? If not, you may need to illuminate it with something brighter (one of the best night photography investments I ever made was in a brutally powerful, pocket-sized flashlight—I’ve actually driven down rural gravel roads, waving it out the window like a spotlight while looking for interesting scenes to photograph).

If you’re using a bright flashlight on the object and you still can’t see anything on your LCD, this is when I do one of two things: first, I check to make sure I took off my lens cap. If the lens cap is off, I check to make sure that my 10-stop neutral density filter is not currently on that lens. (Both of these scenarios occur with surprising frequency. And they’re both kind of embarrassing.) If you still can’t see anything on your LCD, and you’ve turned on live view, have no filters on your lens, your lens cap is off, and you’re using a powerful flashlight on an object in the foreground, then there’s a strong possibility that there’s something wrong with your camera. Please see my earlier condolences for those photographers who are shooting on a digital camera without live view. Now extend those condolences to yourself, on my behalf.

Step 5? 11?: Zoom in on the object that you’re illuminating in your foreground. On a Canon camera, this is accomplished by using buttons with magnifying glasses and + or – symbols on them. Zoom in as far as you can. Holding your flashlight in one hand, use your other hand to manually focus your lens on the object. Get your focus super sharp, then zoom out, and, if you want, turn off live view. You’ve found your focus for that particular photograph.

However, sometimes there is no object in the foreground. Or, at least, anything with any real detail is too far away to light with your flashlight while focusing your camera. In this case, what I like to do is create an object in my foreground by putting my own flashlight there, and pointing it back at the camera. In some cases, if your flashlight is too bright and rendering your live view display into a giant amorphous blob of light, you can place the flashlight at about a 45-degree angle so that it’s not pointing directly at your camera.

Other options include taking off your ball cap and placing it in the foreground, going back to your camera, and then shining your flashlight on your ball cap to find the focus. (Note: A baseball cap is a handy night photography accessory that can shield the side of your lens from undesirable lighting that causes lens flare, temporarily cover the front of your lens should something unexpected happen in the middle of your long exposure, or cover the eyepiece of your camera if you’re worried about light leaking into the eyehole. In short, a dark ball cap is just about standard night photography gear, and you should really think about owning one.)

Other objects that you can focus on at night using live view include the moon, stars or other celestial objects, streetlights, the edges of a backlit object obscuring a light source—in short, any light source you can find can help you out.

Some photographers don’t bother with focusing in the dark at all. In the warmth and well-lit comfort of their home, before they even leave, they find their focus and then tape the focus ring in place with gaffer’s tape. Personally, this seems like a desperate move to me, as throwing sticky tape on any part of my camera or lens gives me the creeps. But if you absolutely cannot find your focus in the dark (maybe you don’t have live view), than it’s probably not a bad way to go. It’s certainly better than taking a bunch of blurry photos.

Landscape Astrophotography 101: Let’s talk about settings, baby (and…

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Focusing in the Dark, Part 2: Warp Speed Ahead…

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Night photography 101: Focusing in the dark

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