Canon 5D MK III User Manual (en)

HDR (High Dynamic Range) Shooting
You can shoot photos with a wide dynamic range where clipping in 
highlights and shadows has been reduced, and photos that appear like 
paintings. This is suited for scenes such as still-life and landscape. In 
HDR shooting, one shot is taken using three images shot with different 
exposures (negative exposure, standard exposure, positive exposure), 
and they are combined into a single image automatically. Shot HDR 
images are recorded in JPEG quality.
* HDR stands for High Dynamic Range.
Set to HDR.
Select [HDR Mode] in the [Shooting menu], and in the dialog box 
that appears, specify the required settings and click the [OK] 
[Adjust dynamic range]: Sets the range of adjustment for 
dynamic range. Select from [Disable HDR], [Auto], [±1], [±2], and 
[±3]. When selecting [Auto], the range of adjustment will be set 
automatically depending on the image's overall tonal range.
The higher the number, the wider the dynamic range will be.
[Effect]: Selects the finishing effect. For specific finishing effects, 
refer to the pages about HDR (High Dynamic Range) shooting in 
the Instruction Manual provided with your camera.  
[Continuous HDR]: If [1 shot only] is selected, HDR shooting is 
cancelled automatically after you finish shooting. If you select 
[Every shot], HDR shooting is continued until you select [Disable 
HDR] in [Adjust dynamic range].
[Save source images]: To save the three shot images and the 
completed HDR image, select [All images]. To save only the 
completed HDR image, select [HDR image only].