The post I put up the last night about my latest landscape was simply copied and pasted from my Facebook post that ran a little long. But some folks have expressed interest in wanting to hear in more detail how I went about creating it. So here we go…
The first and most important step in creating panoramas and HDRs alike is getting the original images shot correctly. With built-in panorama and HDR features in phones, DSLRs, and more programs than you can shake a monopod at, these techniques are becoming more and more prevalent among hobbyists and professionals. Unfortunately, I see so many people who don’t understand how to shoot panoramas correctly, or worse yet, don’t know how to process an HDR to make it, you know, appealing to look at.
Shooting for Panoramas
The most important thing to keep in mind when shooting a panorama is keeping your parallax at a minimum—ideally, non-existent. Parallax is the effect you see whereby nearby objects appear to move by you faster than distant objects, such as the mountains slowly ambling by and power poles whipping by as you drive down the highway. When you move a camera, such as panning on a tripod, you will most likely introduce subtle parallax that will cause catastrophic problems in post. How do you reduce or eliminate this? By making sure the camera rotates on the lens’s entrance pupil (which until today I knew as the nodal point). The short, non-technical explanation is that you will rotate the optics of the lens around a precise point that keeps the perspective of the scene as you pan around. There are special rigs for this type of work, or you can build your own.
However, the further away your scene is from you, the less of an issue this will be. While you should definitely be doing this stuff on a tripod, the above photo was actually shot handheld. Since the foreground tree line was roughly 1/4-mile away from me, parallax wasn’t going to be a huge issue for me. I made a special note while shooting to not create an arc movement, but instead kept the camera in roughly the same space, and rotated my body around roughly where I knew the entrance pupil to be, as I’ve figured it out with this particular camera and lens combo before.
Similarly, for those of you shooting panoramas on your phones, do not try to pan the phone across the scene, creating an arc with your arm. Instead, keep the phone as still as possible, and rotate it in place. This is as close as you can get to rotating it on its entrance pupil to reduce parallax. And for good measure, if you’re using an iPhone or a similar system that creates the panorama as you pan, slow down! Taking a decent panorama on a phone will take a little while; take your time!
This is something I learned about after already doing it (no originality left in the world, right?). The short version is that you can take a series of photos horizontally and vertically and produce a much larger resolution image than what your camera is capable of producing in a single exposure; sort of a poor man’s medium format image.
I was already familiar with landscape photographers taking ridiculous panoramas by shooting a patchwork of images with telephoto lenses. Thus I thought I’d try taking a panorama of a large epic scene by piecing together images shot at 50mm—not too telephoto to require tons of images but telephoto enough to make it worthwhile. It was on this evening on May 25, while I was out taking other photos around Norfolk, that the sun began to peak through the clouds and slowly move across the landscape toward me. I set my zoom lens to roughly 50mm (since I don’t have 50mm prime at the moment) and began to shoot. I started on the right-hand side and shot the lower right image, capturing mostly ground and a bit of sky. Then I panned up carefully, keeping about 30% overlap in mind (forgot to mention that above). Then I panned to the left and got another shot of the sky, then down to the ground again. I continued this pattern until I had my scene, two rows of six images across. Except I actually ended up with 39 exposures…
For those who may have wondered but are too afraid to ask at this point, HDR stands for High Dynamic Range… Imagery. When I was trained in the Pixel Corps, it was mostly used in visual effects and we called it HDRI. It does what you might think—gives you higher dynamic range than normal. What’s dynamic range? It’s the range of highs and lows that your camera can capture; how bright before part of the image clips to white and how dark before the shadows are simply black. This dictates how much you can push things in post, and why I seriously encourage any hobbyist photographer who isn’t doing it yet to shoot RAW. You’d be amazed at what information is preserved in a single RAW exposure compared to a jpeg, which is effectively pre-destroyed for you.
The benefit of shooting HDR for landscapes and other photos (not the technical needs of the visual effects world) is that you can create a scene that looks much closer to what you remember seeing. When you look at a properly done HDR image, it can be surreal in that it’s hard to believe it was captured in a camera, because ultimately, we’ve all been so exposed (ha!) to photographs that we understand on almost an instinctive level what can and can’t be captured. We know that if you shoot a picture inside, the windows will be blown out (yet somehow don’t get that if you expose for the surface of the moon, stars won’t show up, but that’s another post…). HDR allows you to preserve details in the bright sky as well as shadowy landscape within the same image.
Shooting for HDR
Most of my advice about HDR will come down to the post-processing, as that’s where I think a lot of people go off the rails. The shooting aspect is pretty straight forward, depending on how involved you want to get. Most DSLRs will have some sort of bracketed exposure setup. I shoot on the Canon 60D at the moment, and I can set it up to fire three different exposures. This shot was set to fire a main exposure, and then one exposure 2 stops under, and one exposure 2 stops over. The camera achieves this by varying the shutter speed, so keep this in mind if you’re shooting handheld like I was; the overexposed image is going to be a slower shutter speed, and you could introduce unwanted motion blur if you’re not paying attention. Yet another update – 8/27/15: I should probably explicitly mention that you should indeed be shooting HDR images on a tripod if you want to make your life easier in post. Many tone-mapping programs can handle ghosting artifacts, but not all are created equal. Do as I say, not as I do 😉
In my case, I was shooting right into the sunset, so even my slow exposure was plenty fast enough to be a non-issue. I also set my AF-Drive to high speed multi-shot, so as I hold the shutter, it fires off all three exposures, one after another. Thus each patch of the panorama is a single click of the shutter, even though I’m producing three exposures. The other crucial thing is that the camera is in full manual mode. No matter how much the light changes from shot to shot across the scene, I’m capturing identical exposures for the entire final image. If any aspect is being adjusted automatically, the next couple parts of this breakdown would, well, break down…
Update – 8/26/15: Couldn’t have asked for more perfect timing. As soon as this post went into my Twitter feed, Carolyn Stampeen, a fellow photographer who I met through the Pixel Corps, tweeted this gem:
Sunsets are quickly changing. Bracketing exposures isn’t just for HDR; sometimes it helps to get an exposure that works.
— Carolyn (@cstampeen) August 26, 2015