Yes, it is possible to emulate the infrared Aerochrome look entirely within Lightroom through the use of LUT-based custom profiles. Like me, you may read these words and think, "But you need two custom profiles-one for the white balance and one for the channel swap. It won't work!" But like me, you would be wrong. Read on to find out why.
Since getting started with (digital) infrared photography just a couple of months ago, I have become more and more attracted to the look of Aerochrome, specifically, KODAK AEROCHROME III Color Infrared-Sensitive Film 1443, "an infrared-sensitive, false-color reversal film intended for various aerial photographic applications where infrared discriminations may yield practical results." From what I can tell researching online, Aerochrome III 1443 was the last revision of a series of Kodak color infrared films (preceded by 8443, 2443, etc.). (In fact, the "Aerochrome" moniker was used by Kodak to refer to their entire line of color reversal films for aerial photography, not just the infrared-sensitive films.) Color infrared films were originally developed for camouflage detection and were later employed for remote sensing applications with aerial photography. Depending on the lens filter used (Kodak recommended a deep yellow, Wratten No. 12, to block all blue light), Aerochrome produces cyan to deep blue skies with white clouds and renders vegetation in various shades of red, pink, and purple.
Aerochrome has been out of production since 2007, but it can still be found in limited quantities and has been used for some interesting projects in recent years, most notably Richard Mosse's art/documentary works INFRA and Enclave that portray the civil conflict in the eastern Congo. An earlier version of Aerochrome, Ektachrome 2443 EIR, was used in the 2004 Oliver Stone film Alexander in the scene when Alexander is almost fatally wounded in a battle in India to represent the surreal perception that might accompany near-death experiences. As I write this post in 2019, there are many examples of true Aerochrome film imagery to be found on Flickr.
Creating the Aerochrome look from a digital infrared image is not difficult, but typically requires the use of Photoshop or similar pixel editor to accomplish the required red-blue channel swap. Of course, the digital image must be captured using a suitable camera sensitive to infrared wavelengths-I have used images captured with a 590 nm cutoff filter (sensitive to wavelengths longer than 590 nm) for the images presented here. I suspect that digital images capturing less of the visible spectrum (e.g., with a 720 nm filter) may not work as well for mimicking the Aerochrome look.
The basic process is to white balance the raw image, swap the red and blue channels, then adjust the hue of the various colors to dial in the look. If you are a user of Lightroom/Adobe Camera Raw for infrared, then you already know that a custom DNG profile is needed to extend the range of white balance adjustment for infrared raw images. I created a custom DNG profile using the "Camera Deep" profile as a baseline for my converted Sony a6000 camera. I then white balance the image using the eye dropper tool in Lightroom to select an appropriate neutral in the image (such as a cloud). Then the image is opened in Photoshop where I use a Channel Mixer adjustment layer to swap the red and blue channels and a Hue/Saturation adjustment layer to adjust the colors in the sky and vegetation for whatever look I want for the image. Further color fine-tuning can be accomplished by adding a Selective Color adjustment layer. I used all three adjustment layers to dial in the reds for the image of the Rio Grande Gorge Bridge northwest of Taos, New Mexico.
With the 7.3 release of Lightroom Classic in April 2018, Adobe implemented a new Profiles feature that allows for the use of color lookup tables (LUTs) to create color profiles. I previously explored how these LUT-based color profiles could be used to invert and color-correct digitized color film negatives so I imagined profiles could also be used for swapping the color channels of infrared images, except for the white balance issue. Since a custom DNG profile is needed for proper white balance, I did not think it would be possible to also apply a LUT-based profile without counter-acting the white balance profile. But then I came across a post by A. Cemal Ekin demonstrating how he created a LUT with a red-blue channel swap on top of the white balance profile (be sure to refer to his detailed instructions).
I followed the instructions he provided, but the first time I tried to create a LUT, something didn't work right and the image was completely blue in Lightroom after the Aerochrome profile was applied. I tried again, making sure to follow each step exactly, and this time it worked! The image required some white balance adjustment in Lightroom after the profile was applied (the eyedropper tool will no longer work), but otherwise the LUT worked very well. I think the trick is to make sure in the Profile dialog in Camera Raw that the Basic Settings box is checked and that ProPhotoRGB is selected as the color space for the LUT.
Using a LUT to swap color channels and produce quality results without artifacting is really asking a lot, but it can provide exceptional results. The outcome will vary by image. In general, I think LUTs can provide a useful option for rapidly testing out various looks for false color processing and can even be good enough for images that will be shared on social media or on a blog. For an image that I wanted to print, it would be worth the extra effort to make the color adjustments in Photoshop. Based on what I've seen so far, I plan to create a set of LUTs for my false color images and use them first in processing images. Then depending on how well the conversion looks and where I want to go with a specific image, I'll make a decision on whether to use Photoshop.
The best results will be obtained when the capture conditions match the conditions of the image used to create the profile. The first image in this post of the Rio Grande Gorge Bridge was used to create the LUT in Photoshop; I got excellent results using that LUT on other images of the gorge and bridge. These last two images from Palo Duro Canyon were processed using the same profile, but were captured 6 weeks earlier on an overcast day in a different state using the same camera but different lenses. I had to spend more time setting the white balance and working with the color calibration panel in Lightroom to dial in the look. The results are not as good-probably acceptable for Instagram and good enough for me to evaluate the image and decide where I want to go with the image, but I would re-process these images in Photoshop if I wanted to print or add one to my portfolio.
Despite the possible limitations on image quality, LUT-based profiles offer a lot of flexibility for processing false color images. The image below was processed in Lightroom using the exact same profile with different adjustments in the color calibration panel (primarily the Blue Saturation slider). I had previously created a similar version of this image in Photoshop, but comparing them now I prefer the Lightroom version. LUT-based profiles are very powerful-I suggest you give it a try!