I’ve been shooting HDR images for a long time and if there’s one thing I’ve learned over the years it’s how the finishing touches can make all the difference. HDR photography is incredibly polarizing. When most people hear the letters “HDR” they almost always make a sour face and say they don’t care for it. One look at an overdone HDR image and you’ll quickly understand why HDR photography gets a bad reputation. Whenever I see an over-the-top HDR I usually say: “that place looks like it had a nuclear accident” and good photography should show viewers interesting subjects in places they’ll want to visit, not places they want to avoid.
Luckily HDR photography comes in many forms and when it’s really done well the viewer stops thinking about how the image was created and they just enjoy what they’re looking at. For this article I’ll be talking about my background in HDR photography and sharing some of the finishing touches I apply to my HDR photography today.
My background in HDR photography
I got my start with HDR photography about 10 years ago when I worked in the Advanced Visualization Group of Ford Design North America. Back then I wasn’t shooting bracketed sets of images and processing them with software like Photomatix or HDR Efex Pro. I used a very specialized camera that could capture a complete 360 degree shot at a full 96 bit depth that results in 26 stops of dynamic range (compared to the 12 stops of dynamic range I can capture with my full frame A900) and do it all in a single shot. The camera was called a Spheron VR and it was an awesome piece of gear. The 50 megapixel captures were used by digital animators to create super realistic environments for their rendering projects. Here’s a look at the Spheron VR camera system in use:
Using a camera system like the Spehron taught me a lot about capturing HDR images as well as something called tone-mapping.
Tone-Mapping a 96 bit HDR image
One thing I learned when I used the Spheron VR is that the raw file doesn’t look very good. A 96 bit image contains information way beyond the capabilities of just about any monitor so you needed a special HDR viewer to adjust the exposure of the HDR shot. Using the special software you can look at the image and turn up the exposure to see into the darkest shadows or turn the exposure down to see what’s in the brightest parts of a shot. Unfortunately you can’t do both at once. For that you needed to process the image. The processing used to make a single image that shows both the dark areas and bright areas at the same time is called tone-mapping. Tone-mapping takes all that information and it compresses everything from the 96 bit raw file into something more usable. The resulting 8 bit image lets you see into the shadows and the brightest parts of the shot at the same time. The idea behind tone-mapping is to create a single image that comes close to what we would see with our eyes if we were at the place where the image was captured. The resulting image is often called “HDR” but it’s really a tone-mapped image.
The lessons I learned while working with the Spheron VR helped me to better understand all the technical things that are happening with high bit depth images. That was a special camera but the lessons I learned then also apply to how I create HDR images today.
Capturing Bracketed Sets
The idea behind HDR still photography is to make multiple captures (at different exposure settings) of a scene so that you can combine those shots together into a single image. By capturing a shot that sees into the shadows (with a longer shutter speed) and a shot that isn’t blown out in the bright areas (using a very short shutter speed) you’re collecting information that you can’t capture in a single image. The best way to do this is to mount your camera up on a sturdy tripod and set your camera to capture a bracketed set (check your camera manual to find out how to do this with your camera).
Once you have a group of images you can combine them into a single 32 bit file with programs like Photomatix, HDR Efex Pro or Lightroom/Photoshop. I wrote some blog posts about creating HDR images with Lightroom and Photoshop over on my personal photography blog if you’re interested in learning more (the links will be shared at the end of this post).
Tone-Mapping your 32 bit image
Turning your 32 bit HDR file into a viewable image can be done a bunch of different ways. The software you choose to use will have a huge effect on how your image turns out. When you tone-map an image you can use a preset or you can move sliders around until you arrive at the look you’re going for. You can create something that extends the dynamic range of the shot a little bit or you can create a look that reveals every bit of detail in the shot. To give you an idea what I’m talking about here’s a look at a shot of the Terrace Theater (located in the Kennedy Center in Washington, DC). This is a middle exposure image shown without post-processing:
I look at this shot and I see some serious color casts caused by all of the colored surfaces in the room reflecting light. Also, the exposure of the shot seems a little low and darker areas of the shot are too dark. With a little work in Photoshop I’m sure I can make it better but a HDR capture would give me a lot more to work with.
Now let’s look at the other extreme. Here’s a look at the same scene but I captured three exposure levels and combined them into a single 32 bit HDR. I then tone-mapped the image with Photoshop HDR Pro (using a preset I created to give the maximum amount of detail):
The exposure level is much better and you can see absolutely every detail that was captured. Also, the tone-mapping amplified the color casts big time. If you ask me the final look of this version is way over the top. It’s cool that you can see so much detail (and most HDR photographers really like the grungy look) but (personally) I don’t care for it. If you stopped here and shared this image you’d get mixed reactions from viewers (and most would be pretty negative). This much detail almost makes the screen and walls look smoke damaged (and I’d never want to see a show in a smoke damaged theater).
But the secret to really good HDR photography is not stopping at this stage. There’s good things about these two different looking images that you can take advantage of by bringing them into photoshop (each on their own layer) and blending the two until you end up with a result you like. Here’s a look at what I came up with when I combined the above two shots in Photoshop:
You can see that I went for a very toned down look for my final image. Once I had the blended image I adjusted the exposure and boosted the color saturation (using Photoshop). Unfortunately, when I look at the blended image I see lots of color casts.
The first thing I noticed is how the white screen isn’t white (light in the room is taking on the color of the seats and adding a color cast to the screen). When I look around the rest of the shot I see there are other areas that I think should be white but have a pink tone. The overall impression I have when I look at the shot is that it has a dominant color cast. That color cast effects how I feel when I look at the image and it prevents some colors from popping off the screen. In other words, the image lacks color contrast.
If I wanted to stop now I could share this image and some people might not guess it’s a tone-mapped HDR image. I prefer to take things a bit further by adding what I call “some finishing touches”.
High Color Contrast Images
The first thing I do with all my HDR images is address the colors. High Color Contrast is something that I try to include in every image I show. To get good color contrast I’ll use a an image editing program (like Photoshop) to go in to selectively remove colors from an image. To help you understand color contrast here’s a shot of some orange battery holders on an orange background:
This image was shot in my product photography studio and the color was confirmed by setting white balance with an 18% gray card. The color of the orange battery cases measures around R:228 G:60 B:0 and even though that’s a pretty vibrant color of orange it doesn’t seem like it in the image. Now let’s look at the same shot (with identical lighting and color settings) but on a white background:
If you measure the color of the orange battery cases you’ll find that they’re still R:228 G:60: B:0. The color saturation of the battery cases are exactly the same as the first shot but without the orange background the color looks more vibrant. The reason the orange color pops in the second shot is because we have a contrasting color (or lack of color) next to the orange cases. This is the idea behind color contrast. If you want a color to pop off the screen (or your print) you can only boost the color saturation so much. Instead of trying to get additional saturation I like to remove similar colors from nearby objects. I call the final image a High Color Contrast image (or HCC). Here’s another look at my “Terrace Theater” shot after I removed some of the color from the screen, the ceiling and other areas of the shot:
By taking the color out of the screen the wood really pops in the shot. This selective color removal is an important element in my personal style of HDR photography and it’s one of many different ways to create a unique look to your images. The only downside is that there’s no easy way to remove color from specific parts of your image. You need to do it manually and that can take some time.
Note: there are dozens of ways to desaturate parts of an image using Photoshop. The easiest is to use the sponge tool set to desaturate. Brushing with the sponge tool will remove all of the color just like painting with the brush tool will add color. If you’re going to use the sponge tool method be sure to use it on a duplicate layer (to prevent permanent damage to the image you’re working on) or have a good understanding of how to use the history brush.
The bottom line is this: If you want your images to look their best you should be ready to spend a little time doing things that others may not be willing to do. By working with lighting and camera settings at the time of capture you’re spending time to make your image look better. By spending time in post-production (using software like Lightroom or Photoshop) you’re doing what it takes to make your images look as good as they can.
If you’re like me you consider photography a form of art. I know a lot of artist including some really incredible painters. Whenever I talk with them about their work they don’t talk about how they can make a painting faster, they talk about how they can make their painting look better or more realistic. They will spend as much time as it takes to create that final image and I think photographers should have the same attitude.
More High Color Contrast HDR Examples
I went back into my personal collection of HDR images to find some more examples of shots where I applied some finishing touches after tone-mapping.
This is a HDR image from inside the National Gallery of Art in Washington, DC. The original tone-mapped image looked good but the black marble floor and the white ceiling took on the color of the walls. I used photoshop to remove the color casts from the floor and ceiling to help the colors in the rest of the shot look more vibrant.
This is a HDR shot of Space Shuttle Enterprise on display at the Smithsonian Air and Space Museum. One thing that can really trip up HDR photography is having multiple sources of light. A tone-mapped image in difficult lighting starts to take on all sorts of color casts that need to be worked with. It’s not just a matter of removing all color from some items in your shot, sometimes you need to remove a single color and leave the others alone to get an accurate looking shot. That was the case with this shot.
To get the final image I had to remove color casts from the floor and from the shuttle. I was looking for great color vibrance without unusual color casts and I ended up with an image I was really happy with.
Here’s one final example image:
This is a shot I took inside the Lincoln Memorial on Inauguration Day (2013). Inside the memorial there’s a combination of natural light and artificial light that looks great in person but can trip up an HDR image. What I wanted to do with this shot was make sure that the statue didn’t blend into the background. To arrive at the final image I did some color work to the statue to make sure it stood out in the shot. Another trick I use is adding glow to parts of the image to soften some areas of the shot. Because our eyes seek out the sharpest parts of an image first I softened parts of this shot to help direct viewers to the statue first (I prefer the look of glow to blur). You have to be careful when adding glow or blur since too much of a good thing can ruin your shot.
I love shooting and processing HDR images. When it’s done right a viewer may not even know that they’re looking at a HDR image. The only downsides to this kind of photography is it takes time, good software and serious computing power to get great results. The thing I love the best about HDR photography is that there’s no single way to arrive at a final image. Two photographers shooting the exact same scene could create completely different final images because they’re each sharing their own personal interpretation. It’s the finishing touches we add to our HDR shots that will make all the difference.
You can learn more about how I process HDR images by checking out these posts over on my photography blog:
If you want to learn more about using Lightroom 5 I highly recommend checking out “The Adobe Photoshop Lightroom 5 Book for Digital Photographers” by Scott Kelby.