Canon PowerShot S120 Manual (en)

Creating HDR (High Dynamic Range) Images
You can create images with a wide dynamic range where clipping in 
highlights and shadows has been reduced, and images that appear like 
paintings. This is suited for scenes such as still-lifes and landscapes. 
This function is most effective when using three images with different 
exposures for the same scene (negative exposure, standard exposure, 
positive exposure) to create an HDR image. However, you can also 
create an HDR image from two images, or even only one.
Since an HDR image is saved as a separate image, the original images 
remain as they are.
* HDR stands for High Dynamic Range.
This function can be used with all image types 
 supported by 
Image information is not appended to an HDR image. 
Select an image in the main window.
Select the [Tools] menu  [Start HDR tool].
The [Select Images] window appears. 
You can also display the [Select Images] window from the edit 
window and edit image window.