Canon EOS-1D X Manual (en)

Editing with the Lens Correction Tool Palette
With the Lens Correction tool palette, you can use the lens aberration 
correction functions and the Digital Lens Optimizer to correct lens 
aberration in your images and to improve their resolution. This tool 
palette can also be used in conjunction with the sharpness adjustment 
functions. Note that the lens aberration correction functions and the 
Digital Lens Optimizer can only be used with RAW images.
Select an image in the main window, etc.
Display the Lens Correction tool palette.
You can easily make corrections to drops in peripheral illumination, 
distortions in the subject, and color blur which occur by the physical 
characteristics of the lens or slightly remaining aberration.
Note that you can only correct aberration in RAW images which have 
been shot with compatible lenses. JPEG or TIFF images cannot be 
Correcting Lens Aberration
To use this function, the EOS Lens Registration Tool (version 1.4.20 
or later) must be installed.
Lenses compatible with this function are those displayed in the 
[Add or Remove lens data] window 
You can also correct RAW images taken with the compatible lens 
even when the extender is attached.
You can also correct RAW images shot with EF 50mm f/2.5 
Compact Macro fitted with Life Size Converter EF.
The aberration correction function is not available for images shot 
with a lens other than those given under “Compatible Lenses”. 
They are therefore not displayed and cannot be used.
The lens aberration correction function is not available for 
multiple-exposure RAW images created on the camera.
EF cinema lenses (CN-E lenses) are not compatible.