Creating a lens profile

To generate a devignetting profile:

1. Generate a flat field reference file. This is an image of a grey card taken with the lens, filter and combination of your camera's settings (e.g., on the Leica M8 or M9, lens detection on/off, IR filter on/off) that you want to correct for. If your camera has automatic lens detection, you should typically, have this off. You should overexpose by between 1 and 2 stops – enough to get the brightest possible field, without the highlights in any channel blowing out. It's important that the lighting be as even as possible, and the camera be exactly aligned with the grey card.
2. Double-click on CornerFix to start it
3. Load the flat field reference file by going to File->Open
4. Create a lens profile by going to Lens Profile->Create. Note that this can take several minutes.
5. When the profile is ready, a thumbnail of the corrected flat field reference file will show on the right hand side of the screen.
6. To save the profile, go to Lens Profile->Save As. CornerFix will suggest a filename which is the same as the reference image, but with the extension “.cpf”

Batch creating devignetting profiles

To batch create a number of devignetting profiles:

1. Double-click on cornerfixw.exe to start it
2. Select the reference image files from which you want to generate profiles by going to Lens Profile->Batch Create. You can then select a group of images, either by using the Cnrl-click to select individual files, or shift-click to select a range. Note that all files must be in the same directory.
3. CornerFix will then cycle through all the selected images. The profiles are written as the original file name with an extension of “.cpf”.
4. On completion of the batch process, CornerFix unloads any loaded image file, and any loaded profiles.

Warning: Any old profile files (ending in “.cpf”) with the same name as a newly generated files will be overwritten without warning!!!