This is the final installment on infrared channel swapping in Lightroom. This time, we will go through Photoshop and use a channel mixer layer to swap the channels. In the end, we will have a profile that can be used from the camera profiles menu both in Lightroom or in Adobe Camera Raw.
The initial step outlined and explained in detail in the earlier article to shift the temperature slider scale for white balance is still necessary. If you have not done that yet, please visit the first installment of this latest series and create a new profile before going any further. You need to complete the steps under the heading First thing First. If you created the necessary camera profile from the previous article, you may use that without going through the same steps again.
Open an Infrared Image Using the Above Profile
You can do this best by opening the file directly in Photoshop rather than pushing it from Lightroom. As the image loads in Adobe Camera Raw, make sure to apply the profile created above. Then open it in Photoshop by clicking on “Open.” Then, follow the steps below.
Channel Mixer to Swap Red and Blue
- From the Layers palette on the right, click on the “Create a New Adjustment Layer” icon at the bottom; it is a circle with half white half black segments
- From the menu that pops up, click on Channel Mixer
- Select the Red channel, change the amount of red to zero and blue, 100
- Select the Blue channel, change the amount of blue to zero and red, 100
- Optionally, select the green channel, change the amount of green to zero, red, and blue, 50 each
Export Color Lookup Tables
- Go to File/Export/Color Lookup Tables (LUT)
- In the settings pop up, enter a description for this LUT; optionally add a copyright holder name, and leave all others unchanged
- Click OK to see the file save location window
- Enter the same descriptive name here as well for the file name
- If the location is not the default Camera Raw folders, make a note of the folder location as you will need it in short order
- You can now close this file, press Ctrl-W and you do not need to save the file unless you want it for some reason
Import Color Lookup Tables to ACR
- Open the same IR raw file from Photoshop; it will load it to Adobe Camera Raw
- Make sure the same camera profile is selected as before, and click on the Presets icon on the right; see the images below
- Now, hold the Alt key down as you click on the New Preset icon at the top of the panel; this will open the new profile window rather than the new preset window
- In the settings pop-up window, you should see the camera profile with a checkmark next to it
- Add a descriptive name for the profile at the top, and select a group that should contain it
- Now, click on the checkbox next to Color Lookup Table at the bottom, which will open a file open dialog window
- Navigate to the folder where you saved the exported LUT above, and click on the file with the CUBE extension
- You will return to the previous window; you will see the table name and the Space field showing sRGB
Save the New Camera Profile
- I am not sure if this is necessary, but I changed the Space to Adobe RGB or Prophoto RGB
- Leave everything else the way you see
- When you click OK, the new profile will be saved in its appropriate folder and become visible to Adobe Camera Raw and Lightroom under the group where it is saved
You can see the difference between the green channel left alone or split 50-50 between the red and the blue channels. It is a subtle difference, but it is there, nevertheless.
You can now select this new profile either in Adobe Camera Raw or Lightroom from the profile browser. It will appear under the group you selected for it when creating it.
Using a profile will apply all the changes you made in Adobe Camera Raw or before exporting the Lookup Tables, but not alter any adjustment settings in either application. For instance, if you adjusted the tone curve, applying the profile will not show the tone curve with the changes. You may intentionally or accidentally apply the same adjustments twice, beware!
Other Things to Consider
The processes I presented in this series of articles are important in their sequences. There is room for experimentations in various stages by varying the amounts of changes. I will make some suggestions for you to try on your own. However, keep in mind that if you apply a profile to a bunch of images and later decide not to keep them, all those images will lose their look and much of the edits. I suggest creating a collection in Lightroom made up of virtual copies that can be discarded if you decide to delete some of the profiles later. Careful naming and note-taking are important in these experiments.
In the DNG Profile Editor
- In the Color Tables panel, you can select different starting camera profiles and follow with the rest. Since the starting points will be slightly different, the resulting profiles will attain different looks.
- The Tone Curve panel can provide additional adjustment, but be careful and take notes
- The instructions indicate in the Color Matrices panel to drag the White Balance Calibration Temperature slider to -100. This is not written in stone. I have experimented with -25, -50, -75, and -85. The last one was promising as it did not shift the Temp slider in Lightroom white balance panel too far to the right.
- You can adjust the individual color channel sliders to your liking. It may be best if you try one variable at a time first, then combine them for different effects. Don’t forget to take notes and why you are doing it.
In ACR or Lightroom
- When using a camera profile, you can use the Amount slider to increase or decrease the profile effect.
- The channel swapping using a Graduated Filter and shifting the Hue mapping slider does not have to be all the way to the end. There is no hard rule, try moving the slider 80% – 90% to the right or left and see the results.
- Instead of using a Graduated Filter, try a Radial filter and leave the corners fading to the natural colors of the original for a different effect.
- Before creating a preset or a profile, you may add more adjustments in ACR like lens corrections, sharpening, etc. Keep in mind that when using such a preset or profile, you should not apply the same settings in the native application by turning on, say, the lens corrections in Lightroom as well. This will be visible in a preset but not in a profile.
- Likewise, you can change the tone curve to adjust contrast before saving the preset or profile. If used, the tone curve will reflect these changes if applied via a preset, but it will not be visible if applied via a profile.
- The color channels in the Calibration panel are available for experimentation as well.
- As you use the Channel Mixer adjustment layer, you may split the green channel 50-50, or any other ratio between the red and the blue channels.
- You can apply a Curves adjustment layer for contrast or color channel adjustments above the channel mixer layer. If you do, make sure that is also selected in the export Color Lookup Table stage by putting a checkmark if not there already.
As you do all this, remember that these experiments can yield literally an infinite number of iterations and can quickly become a time-sink! Your experiments will likely yield different results partly because of the different cameras we may use and partly because of the settings we may have, starting with the “white balance.” Look at these experiments as ways of fixing problems that otherwise resist solutions or achieving a particular vision. Don’t sit and experiment by moving sliders without a plan unless you have time to spend, well, waste!