Infrared (IR) photography creates pictures in a whole new light. When I first experimented with infrared in the late 70's early 80's it was with black and white infrared film using a dark red Wratten 89b IR filter. It was okay, but not great. Digital cameras change that by opening the experience to easy experimentation to explore color and black and white.
The first step is converting a camera. Several places do this. LifePixel is a popular choice and is close to Seattle, which makes shipping back and forth quick to suit my impatience. I converted my Nikon D300s. It served my well from 2010 to the end of 2014, when I upgraded to the higher resolution, D7100 and D750 models. At 12 megapixels the D300s provides sufficient resolution to make reasonable sized prints if I want, and I can use my existing lenses.
Digital camera sensors can capture light of many wavelengths. Most cameras contain a filter to block light in wavelengths greater than 700nm (where the infrared spectrum begins). This limits the light that passes through to the sensor to be in the visible spectrum. Thus, a common conversion is to replace the existing filter with one that blocks light with wavelengths shorter than 720nm. Other conversions are possible with filters ranging in various steps from from 590nm to 830nm. With some cameras, lens filters can be used to achieve similar results, but they also block a significant amount of light, which constrains the overall photography experience.
With my converted camera in hand, the next step was to get some experience. My go-to spot is the Ballard Locks in Seattle. With many scenes captured, it was time to investigate my new images. "Out of the box" images have a red cast. A lot of sites emphasize calibrating the camera's white balance. However, if the images are captured in raw format, the white balance can be adjust in post processing. Interesting black and white contrasting images can be created with minimal white balance adjustments. But, if color effects are desired, the white balance temperature must be set well below 2000K.
Setting white balance below 2000K requires a trick. The trick, described in full at https://robertreiser.photography/proper-infrared-white-balance-in-lightroom, is to create a camera profile using Adobe's DNG profile tool. The process involves exporting an image as a DNG (Adobe Digital NeGative), opening it in the profile tool, setting the temp (under the Color Matrices tab, White Balance Calibration panel) to -100, and exporting the profile with a recognizable name such as "mycamera infrared." The DNG file is needed to be able to export the profile. On a Mac, this profile is added to ~/Library/Application Support/Adobe/CameraRaw/CameraProfiles.
The next step is to set the white balance of an image in Adobe Lightroom. This is done in develop mode by navigating to the bottom panel - Camera Calibration - and selecting the new profile. Then by navigating back to the top panel - Basic, the Eye Droper tool can be selected and used to adjust the white balance by clicking on a gray region in the image. This sets the image's white balance in a single step. The Temp and Tint sliders can then be adjusted to further refine the image if desired. A side effect of the profile is that the initial Temp is arbitrarily set to 50,000K (the maximal right hand value).
Images adjusted in the above manor have IR colors, blues will appear a deep reddish brown, almost like a sepia colorization. The sky being blue in "normal" light will also appear brown. While this effect can be appealing, it is also desirable to have the sky be blue. To apply this effect the red and blue channels need to be swapped. While commonly done in Adobe Photoshop there is also a Lightroom solution at Capture Monkey. This solution is collection of profiles that support many cameras. To enable blue / red channel swapping in Lightroom add the downloaded folder - redblueswap - to ~/Library/Application Support/Adobe/CameraRaw/CameraProfiles as above. Similar to setting white balance, select the redblueswap option in the Camera Calibration panel. If the image was previously white balance adjusted, it will turn bright green. Simply readjust the white balance with the Eye Dropper tool and the image will properly adjusted. Temp will be close to ~50,000K and Tint will be close to -150.
The table below provides example images that were processed with the different white balance and red/blue channel settings. Additional information on processing can be found at https://photographylife.com/how-to-process-infrared-photographs. Bob Vishneski provides a nice description of the process. As a last tip, I found that having my in-camera review set to the RBC histogram mode was very helpful. The red channel is often shifted to the right (over exposed). As you cannot see IR light, it is hard to gage exposure. My first photo shoot was done in aperture priority and had to set the exposure (EV) composition -1 or -2 stops to shift the red channel to the left.