Both functions compensate for the brightness and contrast automatically. Select an appropriate mode for the subject or the shooting conditions as follows.
Shoots 3 images with different exposures, and then overlays the bright area of the under exposed image and the dark area of the over exposed image to create an image with rich gradation. The highlight detail in auto HDR is often better than that in D-Range Optimise reducing the noise. However, as the shutter is released 3 times, using this function for moving subjects is not recommended. If you shoot moving subjects in an environment where there is a large difference in brightness, the recorded image may look multiply exposed.
Analyses the contrast and produces the image with the optimal brightness and gradation. You can use this function even while the subject is moving or during the continuous shooting. When shooting with the D-Range optimise, the image may be noisy.