Using LCC in Capture One with your Aptus raw files
When using a view camera with lens displacements, you may see some color cast and luminance falloff in your images, this happens mostly with wide-angle lenses. To read more about these phenomena please follow this link: Cast effects with wide angle lenses
Capture One provides a comprehensive set of tools for correcting color cast and luminance falloff that are located in the Lens Tool Tab:

image 1: LCC tool in Capture One
In order to use the LCC tool, your images must be saved in a RAW lossless-compressed type. This can be done in 2 ways:
Shooting to a CF card (22, 28 and 33MP backs)
On the Leaf Aptus-II 5, 6 and 7, if you would like to use the LCC function, you MUST select the Compressed (lossless) format; otherwise the LCC tool will appear grayed out and will be disabled.

Image 2: Lossless compression setting
On 40, 56 and 80MP backs there is only 1 option which is Compressed-Lossless.
You can check the type of file by looking into the Metadata tab:
A RAW file that was shot compressed to a CF card will appear as RAW:

Image 3: RAW means LCC is enabled
A RAW file that was shot uncompressed to a CF card will appear as MOS:

Image 4: MOS means LCC is disabled
Shooting tethered to Capture One
Capture One, by default, uses the Compressed (lossless) format and thus enables the use of the LCC tool, therefore there is no choice of different formats. These files will be designated .MOS(in CAPITALS) when viewed in the Mac OS Finder or in Windows File Explorer and appear as RAW in the metadata.
Important Notes about Leaf Capture
A Leaf raw file that is opened in Leaf Capture and re-saved, or that was shot into Leaf Capture, will have its format changed. It will still have a .mos extension (or .MOS if shot into Capture One) however the ability to run LCC correction on it will be lost.
When shooting tethered into Leaf Capture, whether compressed or uncompressed, the file will not be able to undergo LCC corrections in Capture One.
Leaf Capture has its own Lens Calibration tool, which is very powerful, and it allows you to save a corrected, fully archive-able RAW file. To read more about it please refer to the Leaf Capture Help menu.
If you are facing any issues please contact our support team:
http://www.phaseone.com/en/SupportMain.aspx