Canon EOS-1 DX Mark III Advanced User's Manual page 483

Caution
Processing RAW images in the camera will not produce exactly the same results
as processing RAW images with Digital Photo Professional (EOS software).
If you perform [Brightness adjustment], noise, banding, etc. may be intensified
with the effects of adjustment.
When [Digital Lens Optimizer] is set, noise may be intensified together with the
effects of correction.
When [Digital Lens Optimizer] is set, image edges may be emphasized, under
some shooting conditions. Adjust sharpness of the Picture Style as needed.
Processing with [Digital Lens Optimizer] set to [High] may take some time.
Dust Delete Data (
[Distortion correction] set to [Enable].
Note
Lens correction data for lenses compatible with this feature is registered (stored) on
the camera.
Effects of lens aberration correction vary by lens and shooting conditions. Also, the
effect may be difficult to discern depending on the lens used, shooting conditions,
etc.
For details on the correction data used with Digital Lens Optimizer, see
Optimizer.
RAW movies cannot be processed. Process them with Digital Photo Professional
(EOS software).
) is not added to images when processing is performed with
483
Digital Lens