During my visit to Patriot’s Point in Charleston, SC, I snapped this picture of the USS Yorktown aircraft carrier captain’s chair.
Seemingly an easy exposure enough, but with the bright sunlight, it created a wide dynamic range (range from the brightest pixel to the darkest pixel) that it poses a challenge for most digital cameras. How so, you ask? Take a look at the original exposure below.
You can see that while the out-the-window view of the Ravenel cable-stayed bridge is about the same as the post processed photo, the details of the ship’s bridge is almost completely lost in the shadows. Even large portions of the captain’s chair is lost. So how do you capture a photo like that in the first image above, that shows a balanced exposure from the outdoors to the indoor elements?
There are actually a number of techniques. You can:
- Wait until the outdoor light balances that of the indoor level. For this, you would have to wait closer sunset or come back the next day around sunrise. This is not practical if you are on a tight schedule.
- Take a High Dynamic Range (HDR) image. An HDR image is actually taken as a three or more bracketed exposures (over exposed, normal exposed, under exposed) and composited together in Photoshop or similar tool. This usually requires a tripod to ensure the composition remains exactly the same across all three images, to facilitate the compositing.
- Use fill-in flash: You could use a flash to raise the light levels of the interior to better match that of the outdoor elements. This will work well for small spaces that can be easily lit up with your flash unit.
- Or you can take advantage of the newer DSLR’s wide dynamic range to bring out the shadow details using a raw post processing software such as Adobe Lightroom. Ah, this is the technique discussed in this article. Read on…
To do this, follow these steps:
1. Set your DSLR to capture images in raw (or raw and jpeg). Raw files have much greater information that can be used to post process the image. In this case, raw files have greater dynamic range in exposure. In the case of my Nikon D600, it has 14-bit raw images stored as *.nef files. The price of capturing images in raw is that the file sizes are substantially larger than JPEG files. My 24 Megapixel Nikon D600 produces 25-26 Mbyte raw files.
2. Taking the exposure, set your exposure by optimizing for the brightest area of the image. In my example, that would be the out-the-window elements such as the river and Ravel bridge in the background. Let the other portions of the image fall as they may (underexposed).
3. Load the raw images into an image post processing tool such as Adobe Lightroom.
4. The first adjustment is to bump up the Fill Light setting until the shadow details are visible and tastefully balanced with your vision of the image. In the case of my image, I raised the Fill Light setting all the way up to 100 (maximum). The more Fill Light is raised, the more noise will be introduced in the same shadow areas that are lightened. Minimizing the noise artifacts is the reason why you only want to use the minimum amount of Fill Light as possible to achieve your artistic vision. During this process, don’t worry about the bright areas becoming over exposed. (We will compensate for this in the next step.)
5. Next, use the Exposure setting to reduce the bright areas if they were over exposed from the Step 4 Fill Light adjustment. For my example, I reduced the exposure by -0.67 (effectively 2/3 of the stop) to bring down the outdoor elements. This of course lowers the exposure value of the entire image, so the shadow details start to fade back into shadow again.
6. Repeat steps #4 and #5 iteratively until you get the results that is most artistically pleasing. That’s it!
To finish things off, I frequently set the Clarity the +5, Vibrance to +5, and Saturation to +5 to give the images some punch, especially if I am using my all-purpose Nikon 28-300mm zoom lens, which can use that little extra punch every now and then. Of course, these settings are optional and are not germane to the Wide Dynamic Range post processing technique that I discuss here.
I find this Wide Dynamic Range technique a quick way to capture tough exposures by taking advantage of the newer DSLR’s dynamic range, as captured by the camera’s raw file. It is easier than having to wait until sunset when the light is more even outdoor vs. indoors; quicker than taking HDR exposures and its HDR processing; more viable when you don’t have a tripod with you, or not allowed to use one; or when you don’t have a flash unit on hand to balance the light. The trade off is more noise in the shadow areas. But otherwise, Wide Dynamic Range exposure is yet another technique of Harvesting the Light to realize your artistic vision.