Most photographers are familiar with the limitations of modern cameras. Often we encounter scenes with a high dynamic range that forces us to expose for the highlights (or shadows) and work on a fix in post-production. Important details are lost when we do this. The High Dynamic Range (HDR) process attempts to solve this problem by combining a series of raw exposures to create a single image that displays a scene similar to how our eyes would perceive it. This article assumes basic knowledge of creating bracketed exposures (either manually or automatically) with your DSLR, as well as basic knowledge of RAW processing with tools like ACR or Lightroom, and editing with curves adjustments.
Here are a few of the things you need to keep in mind when working with multiple exposures for HDR:
• Do not change the focal length, focus point or aperture when creating a series of bracketed exposures.
• If your DSLR supports it, use the full frame or “matrix” metering mode.
• Use a tripod or Vibration Reduction (VR) lens if you can. Camera shake can cause problems in HDR.
• It’s OK to make a few RAW edits before merging to HDR; just be sure to synchronize the edits, and stick to settings that do not affect contrast or color (I usually apply a crop and noise reduction.)
Photoshop offered basic HDR tools in the past, but it was not until Photoshop CS5 that we were given a complete set of tools for making HDR images. To start, choose File > Automate > Merge to HDR Pro. From the dialog that appears, choose a series of bracketed exposures from your hard drive and make sure to select “Attempt to Automatically Align Source Images” before beginning. Note: the process of merging your documents may take a minute or two, depending on your system hardware.