I happen to be doing some HDR work today, so I thought I’d put this post together while I’m working. My wife is a REALTOR® on Maui and I shot one of her listings in Kihei. Real estate photography is tricky. You usually have to choose between getting a good, well-lit shot of the interior or one of the scene outside through the windows. The former yields blown out windows, and the latter yields a shot of the interior in darkness.
It used to be that the only way to get both the interior and exterior in the same shot would be to meter for the outside and use elaborate lighting equipment to fill in the details inside. Now we have HDR. HDR stands for High Dynamic Range, and is a technique that allows you to capture the full range of light intensities within a scene, from bright to dark.
When we look at the scene, everything looks well exposed to us. This is because the human eye is capable of seeing about 20 f-stops of light, so we can perceive fine details in light and shadow very clearly. A DSLR is only capable of roughly half the number of f-stops, so in photography, we have to choose between capturing the highlights or the shadows. If you choose one, you sacrifice the other.
If done well, you can produce some nice effects, depending on whether you’re looking for silhouettes or a blown out look. But if you want to capture a balance of both, you have a challenge on your hands. There are techniques you can use to compensate somewhat. Shooting in the early mornings or late evenings when the light is soft is one. Or you can use an ND Grad if it’s appropriate for the scene. Or there’s always the old splice-pieces-of-differently-exposed-images-together-in-Photoshop trick.
Or there’s HDR. Essentially, you take several images, one with the scene metered properly, then a few overexposed and a few under, and let the HDR software blend the images together to give you a good composite of the darks and the lights. Photoshop has included HDR capability for a while now, and I’ve heard it’s improved greatly as of CS5, but for my money, Photomatix Pro from HDRsoft is still the best.
The example I have here is pretty extreme. Normally, I would take three or four shots—one metered correctly, then one or two above and below. In this case, I not only wanted to capture a good range between light and shadow, I wanted a very wide range, in case I felt like playing with artistic effects later.
For this scene, I took a total of 11 shots, varying one stop each. I basically kept stopping down until I didn’t see anymore “blinkies” in the LCD display.
Photomatix is great at aligning images by correcting for shifts or matching features, but I used a tripod for certainty.
As you can see, the shot with the front entrance exposed properly has blown highlights all over the place—the sky, reflections on the glass, etc. And in the shot where the glass, sky and trees are exposed properly, you can’t really see anything else in the image.
Per my usual workflow, I start in Lightroom, select the shots and export them to Photomatix using their Photomatix export plugin. After I select the options, Photomatix does its thing and produces the blended image.
The resulting image actually looks pretty bland. Remember, all the shadows are exposed correctly, as are all of the highlights, so you don’t have any contrast, which is a vital component in a good photo. So, the next step is to do some tone mapping—essentially setting the values of light and dark so that you get a compelling image.
This can be done completely in Photomatix, but what I like to do is take it part way, then re-import it into Lightroom to finish it. I like to do this because I have better tonal and color control in Lightroom, and its noise and sharpening controls are also much better, in my opinion.
That’s pretty much all there is to it. I’m oversimplifying the process a bit, but this is the general idea. If you play with the various options, you’ll end up with a realistic rendering or an artistic one, whichever suits your purpose. Try it for yourself. Share a link to your work below so we can all enjoy it.