Processing infrared RAW files
Over several years we worked on a custom B&W RAW converter (IRawMono) for monochrome IR cameras, but with the changes in sensor technology (one example of which is the special DNG handling currently required for Lumix G1 photos) and the continuing developments in RAW software, in the end we've decided it's more effective to use the Adobe RAW software (Camera Raw and Lightroom).
The detail and dynamic range the Adobe software can extract from the RAW files is impressive, but the results and ease of processing can be improved with the right configuration. This page should set you on your way.
One of the biggest issues with using RAW photos from IR-converted cameras is getting the white balance right. For example, the image on the left (from a Canon PowerShot G3 converted with a 715nm filter) has been processed using the default Lightroom settings.
In Adobe Camera Raw 4.6 (CS3) and Adobe Lightroom 2.0, Adobe introduced the concept of "DNG profiles". These allow you to manipulate the way the software treats the colours in your image. One of the usual uses for them is to calibrate Camera Raw so that your various cameras (e.g. Nikon and Canon) render colours in the same way (e.g. some people like "the Nikon colours"). We can also use them to improve the rendering of IR images. You can select the profile in the Camera Calibration panel. This image was rendered using the "ACR 2.4" profile for the Canon PowerShot G3. There's still a lot of red in the image, even at this white balance.
While it is possible to work around this colour cast in Photoshop later, we should try to eliminate it here while working directly with the RAW data.
Newer versions of Camera Raw come with more profiles for each camera, and when you download and install the DNG Profile Editor you get some more as well. By selecting a different profile and white balance, you can improve the situation.
By selecting the "Adobe Standard" profile, we've managed to render more-neutral colours. However, the white balance values are still at the limits of their values. We may be able to work with this, but we also have the option to building our own profile if we don't like the results of any of the standard profiles.
Note that while you need to convert your RAW file to DNG format to feed it into the DNG Profile Editor and create a profile, that profile can then be used with the original RAW files. You don't need to convert all your files to DNG!
When using the DNG Profile Editor's Export Profile function, the profiles (.dcp files) will be installed into the appropriate folder on your system by default. But you can also install profiles provided by others. To install a DNG profile, simply copy it to the appropriate folder on your system:
If you were running Bridge, Photoshop, or Lightroom when you installed the profile, they will need to be restarted to pick up the new profile.
Profiles for monochrome IR filters
The above example is for a camera with a "false-colour" IR filter. The wavelengths it passes through to the sensor interact with the sensor's Bayer filters, resulting in different "colours" appearing in different parts of the image. When using "deeper" IR filters (e.g. 830nm, 87C, etc) the wavelengths that make it through to the sensor still interact with the Bayer filters, but the result is monochromatic. What we need to do is to try to render this monochromatic result as greyscale.
Once you've decided on a profile and white balance that's going to suit your camera, it's time to make that the default behaviour for Lightroom (or Camera Raw). You could save a Develop Preset specifying the appropriate Calibration and White Balance settings, but you would need to specify that preset each time you imported new files. Another option is to make Camera Raw use this automatically for any files from your particular camera. Note that you only have to set it in one application: both Lightroom and Camera Raw share this configuration.
Set the Camera Raw preferences
In the Preferences for either application, set the defaults to be applied to specific camera bodies. This way you can have two cameras of the same model, and only have these settings used for the IR body.
Set up one photo with the new default settings
Load up a RAW photo taken with your new camera into either Camera Raw or Lightroom's Develop module. For now, don't make any changes to the photo. If you've previously processed the photo, reset it to defaults.
On the Camera Calibration panel, select the custom profile for your camera.
Then set the appropriate white balance as discussed above. With monochrome IR filters (87C, 830nm, etc) you may wish to also set the image to greyscale to remove any last bits of colour (which sometimes result from the way the Bayer filter interacts with actual image details).
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