Basic HDR Theory
Over the years, I have used just about every method available to fine-tune my photographs. From burning, dodging, and contrast masks in the darkroom to channel selections and layer masks in Photoshop. Today there are many methods and programs that are far more powerful than anything we’ve had before, and most of these programs are far easier to use! I have settled on Lightroom and Photomatix to produce the look that I find most realistic.
Photomatix was one of the first HDR programs on the scene and has continued to upgrade its product to provide an array of options to satisfy any photographer. Adobe’s early attempts at including HDR processing in Photoshop were less than satisfactory. However, now with the ability to merge and process 32-bit images in Lightroom, the results are fabulous.
Before we get into the specifics of how to use each program, let’s examine the basic HDR process.
- Load multiple exposures into the HDR program.
- The HDR program aligns the images and merges them into a new 32-bit file.
- All tones in the 32-bit image are translated into a visible range. This is commonly called tone mapping, although there are other methods of translating the tones.
- Export or save the file.
As mentioned, you’ll have more leeway when shooting and uploading RAW files. RAW images are 16-bit files, which contain much more information than JPEGs, which are 8-bit files.
Loading the files into the HDR program can be accomplished in several ways:
- If you own only Lightroom 6/CC, select the series in the Library module and choose Photo > Photo Merge > HDR.
- If you own only Photomatix, choose Open and navigate to the images via the Finder (Mac) or Explorer (Windows) window.
- If you have any version of Lightroom and Photomatix, select the images and then choose File > Plug in Extras > Export to Photomatix Pro.
A 32-bit file contains an astronomical amount of information, which allows all the detail in the uploaded series to be contained in a single file. This single 32-bit image, however, contains more information than our eyes can see or the computer monitor can display. This is the only true HDR image. For this reason, you have to translate all the information into viewable tonalities. This translation process is commonly called tone mapping, and it’s the part of the process in which you move the various sliders to adjust the look of the image.
There are other processes that will translate the tones into a visible range. One of those processes is called exposure fusion and is found in Photomatix. Although this is technically not an HDR process, it’s the one that I find produces the most realistic results.
Figure 4.19 is a classic case of adjusting the RAW images before blending them in Photomatix. I used the Camera Landscape profile to boost saturation and contrast in the bricks. Keeping the white balance set to Daylight allowed the walkway to retain its blue hue from the sky. The darkest and middle image had the highlights reduced to darken the sky. An increase in clarity adds a crisp feeling to the walkway.
Figure 4.19 Image blended in Photomatix with pre-adjustments to initial RAW images
ISO 100 • f/9.5 • 6 sec., 3 sec., 1.5 sec. • 18mm lens