How to get Nikon ICM profiles
Capture NX-D, Capture NX 2 and ViewNX-i are proprietary Windows programs provided for Nikon cameras and are able to accurately develop raw images to match the in-camera rendering. Behind the scenes, these programs generate ICC profiles which incorporate recipes for tonal changes according to their adjustments. Such profiles can be used as input ICC profiles in RawTherapee to lead to almost identical rendering, following the same recipe. The Nikon input ICC profiles are proprietary and cannot be distributed. Fortunately, this software extracts and generates input profiles on-the-fly in a temporary folder at run-time. It is up to you to abide by Nikon's licensing agreement. This process works on registered and trial versions of these programs.
- First you have to install any of these programs.
- Open the NEF file in it, and look inside the hidden folder:
%APPDATA%\Local\Temp\Nkn<random strings>.tmp- The temporary ICC profiles will be created in this folder, with filenames similar to this one:
Nkx_D90_962_1_03_0_00_10_00_00_00_05_00_0200_0_0_476.icm- Under Windows XP the path differs:
%TEMP%\Nkn<random string>.tmp
- Under "Picture Control" click on the "Launch Utility" button. While the utility is running the profiles will temporarily appear in the folders listed above. They appear there because Nikon applies generic profiles to your pictures. These are named "picture control" settings. For example, Capture NX 2 has "neutral", "standard" and "monochrome" profiles. For use with RawTherapee you must simply know that Nikon generates different ICM profiles with every different setting. To ease the choices, the "neutral", "standard", "vivid" and "landscape" settings seem to be similar, apart from the increased saturation and contrast. You can tune the tone curves in RawTherapee, so, in general, a single "neutral" profile should be good starting point.
Note: Other settings may also generate new ICM files! You must be particularly aware that pictures shot under artificial lighting will have different profiles, and using such profiles with daylight shots will result in color casts. D-lighting dramatically changes contrast. If in doubt, just open the particular image you want the color profile for in one of these Nikon programs and use that profile in RawTherapee. In most cases, a generic color profile will be sufficient.