HDR Photography for Interior Spaces
High dynamic range photography is perfectly suited for interior spaces — and the larger the better. This HDR image illustrates the sanctuary of a large church lit with overhead room chandeliers, a few spots on the stage, and ambient light coming in from the windows.
This is a great example of a compromised exposure. The camera is doing the best it can, but it is stuck in the middle. The result is a dark looking room that should be brighter and bright areas around the lights and windows that should be the same or darker. It is the worst of both worlds.
And neither of the following two courses of action, illustrated in this figure, are attractive:
Raising the exposure: Raising the ISO or slowing the shutter speed to make the room brighter only serves to blow out the highlights even more, as you can see in the left side of the figure. Rigging additional lighting to brighten the room would either be too expensive or cumbersome, not to mention that you couldn’t possibly hide the lighting gear from this vantage point.
Decreasing the exposure: Protecting the highlights around the chandeliers and windows requires decreasing the exposure. The problem is that everything that already looks a bit on the dark side slides further into darkness if you do that. Check out the right side of the figure. You are left with a picture of a few bright spots in a dark room.
HDR solves both these problems nicely, as shown in this HDR image. The entire room looks brighter and more vibrant, and the light from the windows has not overpowered the photo. In other words, the best parts of each of the bracketed photos contribute to the final image.
The decisions you make that control how this occurs is what tone mapping is all about. Although some post-HDR processing techniques helped achieve this effect, tone mapping is the single greatest contributor to the overall appearance of this image.
This photo shows you
Flexibility: HDR can work in situations where extra lighting is needed to achieve a better exposure. This is especially helpful for large buildings (which are impossible to light without owning a movie company), landscapes, cityscapes, and large interiors.
Color: When more of the scene’s dynamic range is present, brought to you by HDR, its true colors are free to come out. This is far preferable to the dull original.
Post-HDR processing: It’s often important to continue to edit a tone mapped HDR image to create a finished product. Even with bracketing and tone mapping, the windows were still a bit too bright. An underexposed bracket was used to tone down the windows even more. That option would not be available without the brackets.