Using HDR For Winter Landscape Photography

Nature abounds with colors and contrasts that the human eye and brain are exquisitely adapted to see and appreciate. Unfortunately, the pictures we take of these stunning scenes often appear flat and dull by comparison even when we use high-quality equipment.

The problem is that the range of colors and contrasts available in nature far exceeds the capabilities of conventional image capture, print and display technology. No current device even comes close to reproducing the range of light and color visible to the human eye. This is why the pictures you take of beautiful landscaped and high-contrast scenes don’t always match what you actually saw when you took the picture.

High Dynamic Range (HDR) imaging expands the range of exposure far beyond the limits of conventional Low Dynamic Range (LDR) digital imaging techniques. HDR imaging can accurately represent the wide range of intensity levels found in real scenes ranging from direct sunlight to the deepest shadows.

Traditional display and printing technologies use color models that limit the available gamut of colors to accommodate current display technology. HDR PhotoStudio uses the full spectrum of color visible to the human eye at all times without imposing any artificial limits.

HDR PhotoStudio delivers extreme precision thanks to its 32-bit floating point High Dynamic Range technology that is built into the entire workflow. This technology offers a dynamic range of 1:10^76, which is enough to address any real-world lighting conditions.

In this section, we'll walk through the creation and modification of an HDR Image from start to finish.

Start by opening the Merge to HDR... window from the file menu or typing the "H" key. Add the images to be merged to this list. It is best if the images were taken using a tripod and cable release to reduce camera movement between shots. Depending on the range of the scene it is best to use 5-7 shots at 1 or 2 stop increments. For this example we are using 7 shots taken at -3, -2, -1, 0, +1, +2, +3 ev increments. For this exercise we'll leave the Align Source Images option checked and use the default White Balance option. Once all the files are in the list click on the Merge button to merge all 7 exposures in to a single 32-bit HDR file.

The default HDR image comes up with a median exposure optimized for mid-tones and seems a little flat. This is normal, the first thing we want to do is evaluate the image and see what we have to work with. For this we'll use the Display Brightness slider at the bottom left side of the screen. A 32-bit HDR file contains more image data than can possibly be displayed on a standard computer monitor, so by adjusting the display brightness we can see the full range of the image and identify the portions we are most interested in maintaining.

By sliding the Display Brightness to the right (+) by +2 ev we can see that there is detail in the dark area under the steps

By adjusting the Display Brightness slider to - 5 ev we see that there is quite a bit of detail in the window of the house including the blinds that were not visible at the default display brightness setting. Now we know that we are dealing with approximately 7 ev exposure range. Looking at this particular image I think I am more interested in really going after the highlight information since there is fairly little interesting shadow detail.

Compare detail in the window at default 0 ev Display Brightness. Now that we have evaluated the image we reset the default Display Brightness to 0 ev (short cut click on the -> 0 icon) Note: Display Brightness only affects the viewing conditions, not the actual image data. In the next step we will begin to modify the image so it is important that the viewing conditions are set back to the default value.

With Veiling Glare correction you can both establish a black point for the image and remove lens glare or haze to enhance the dark contrast of an image. Controlling lens glare in an HDR Image is especially important since the effect is multiplied as several images are merged together. In this case I use the eyedropper tool to select a dark spot under the stairs in this image. Then I adjust the strength to -90 to remove the glare and achieve the contrast that I want.

Brightness and Contrast are really the key settings for HDR photos. The over all brightness of an image is controlled with the Brightness slider. You can either adjust the brightness slider manually or use either one of the eyedropper tools to select either the bright point or an 18% grey point of an image. There are two types of contrast adjustments standard Contrast and Local Contrast. The local contrast is similar to what other applications refer to as "Clarity" or "Definition" by default it is linked to the contrast slider so that it automatically compensates to keep the overall perceived contrast constant. If you reduce the contrast the local contrast will increase, if you increase the contrast, local contrast will decrease. It is often useful to first adjust the global contrast with the Keep Local Contrast box checked and then add or subtract local contrast independently to either give the image a little more punch or soften it a little. In this case I've added extra local contrast to just make the image pop a little more.

One image artifact that has traditionally been a challenge to HDR images is the "Halo" artifact, which often shows itself around high contrast edges, for example in this image between the sky and trees. HDR PhotoStudio can significantly compensate for these artifacts with the Reduce Halo Artifact option at the bottom of several panels. This is enabled by checking the box and adjusting the strength with the slider.

As a final processing step to this image, I will adjust the shadows and highlight brightness. In this particular image, I want to bring down the highlights a bit to recover some of the highlights in the windows and the sky and open up the shadows just a bit. This tool is kind of unique in that you first identify a Midtone Point that functions like a pivot point on a seesaw the Highlight Power will affect any value above the midtone point, Shadow Power will affect any value below that midtone point. In this case I set my initial midtone point on the garage door. I then made the highlight and shadow powers and fine tuned the position of the midtone point with the slider. This is also the type of operation that can introduce halo affects so I checked the reduce halo artifact box to correct for that.

HDR PhotoStudio includes additional tools I can use to further affect sharpness, fine tune color, white balance, saturation or noise reduction, but these are the basic steps to go from 7 LDR Raw files to a 32-bit HDR file.

The last step in creating a HDR file is to save it. HDR PhotoStudio offers several differing file formats depending on the intended purpose. BEF is the native format that preserves all the HDR data in true 32-bit floating point precision. For the same reason photographers shoot in RAW, it also makes sense to save one version of the final image in BEF so that you can always go back to the original data if you want to process images for different purposes in the future. BEF offers better compression ratios with no visually noticeable loss of color or detail. If you are processing images for the web or email, it makes sense to save a separate copy as a JPEG file. If the intent is to process and/or print the image from Photoshop we recommend saving the image as a 16bit TIFF file.