Today’s Question: Can you give tips for those of us that don’t have automatic exposure bracketing on our cameras, for capturing an HDR [high dynamic range] image?
Tim’s Quick Answer: As a general rule, if you don’t have automatic exposure bracketing (AEB) as a feature of your camera, you can set an initial exposure in Manual mode and then adjust the shutter speed by two stops for each subsequent exposure until the full tonal range of the scene has been captured.
More Detail: The key to creating a final HDR image that includes the full range of tonality from the original scene is to capture enough images with varying exposures to cover the full range of tonal values within the scene.
When you are using automatic exposure bracketing, this process is generally quite simple. It can be similarly simply when you need to capture each frame individually, provided you take a consistent approach to this process.
I recommend first capturing an image that is dark enough to retain full detail in the brightest areas of the scene. You can use an automatic or semi-automatic exposure mode to determine the best exposure settings if that is easier for you. Then dial in those same settings in the Manual exposure mode.
After capturing the first image in Manual exposure mode, with settings that preserve highlight detail, you can increase the exposure time (use a longer shutter speed) by two stops for the next capture. For example, if you have your camera set to adjust the exposure in one-half stop increments, you can turn the dial that adjusts shutter speed by four “clicks” to increase the exposure time.
Repeat this process of capturing an image and then adjusting the shutter speed by two stops, until the histogram shows that you have captured an image that retains full detail in the darkest shadow areas. I will often actually capture an image that is even brighter than necessary, in order to help minimize noise in the dark shadow areas of the scene.
With this “manual” approach, and with a little practice, you can quickly and easily capture a sequence of images to create an HDR image, even without the benefit of automatic exposure bracketing.