Shoot Multiple Auto Brackets in HDR Photography
In high dynamic range (HDR) photography, if you have Auto Exposure Bracketing (AEB) on your camera, but don’t have the greatest exposure value (EV) range (at and under +/-1.0), you shoot multiple AEB sets one right after another to extend your dynamic range. Here’s how:
Set up to perform a standard AEB set.
You’ll want to be in manual shooting mode or aperture priority for this.
Meter the shot.
For most cameras, press the shutter release (or remote) button halfway down to meter the scene.
Set the underexposed AEB exposure region.
This works just like shooting manual brackets, only you’re shooting bracketed sets.
For example, if you’re using a compact digital camera that has AEB but limits the range to +/-1.0, a normal bracketed set would include exposures at -1.0, 0.0, and +1.0 EV. Lower the initial exposure (through exposure compensation on a compact digital camera without manual mode, or directly with shutter speed on a camera with more control) to -2.0 EV. This set captures -3.0, -2.0 and -1.0 EV.
This example uses an EV difference between brackets of +/-0.7 (two-thirds) of an EV. The EV range has been lowered, as shown in the figure, to center on -1.3 EV. The lower bracket extends to -2.0, and the upper bracket is at -0.7 EV.
Shoot the first set.
Shoot each set as standard AEB. Press the shutter release button (or your remote) and hold it down to finish the set. This figure shows the first three brackets, separated by +/-0.7 EV.
Set the middle AEB exposure region.
Raise the EV to 0.0. This is your center bracket with exposures at -0.7, 0.0, and +0.7 EV. Notice that the lower bracket is a duplicate of the upper bracket of the first set.
Shoot the middle set.
The middle set of brackets acts like a center exposure of a normal bracketed set. If the clouds or other objects are moving too fast and you get smearing in the final image, you can fall back to this set and process it separately.
Set the upper AEB region.
Raise the EV to +1.3. This captures brackets at +0.7, +1.3, and +2.0 EV. Notice that the lower bracket is another duplicate.
Shoot the upper set.
The upper set is collectively overexposed.
In the end you’ll have nine bracketed photos. If you have shot with the exposure ranges in this example, you have exposures at -2.0, -1.3, -0.7, 0.0, +0.7, +1.3, and +2.0. Two of these are duplicates. You can toss those out during software processing.
The final bracketed set comprises seven exposures +/-0.7 EV with a total range of 4 EV. Not ideal, but compared to having too little dynamic range for some scenes, it’s the way to go.