Most digital cameras—be they DSLRs, pocket compacts or mirrorless bodies—have infrared filters in front of their sensors to block infrared light. This makes for better pictures 99 percent of the time when you’re working with visible light, but it’s no good for those interested in infrared photography. So if you slap an infrared filter on most cameras’ lenses, you’re going to make a whole lot of nothing.
One workaround is to send your camera off to a technician who specializes in removing infrared filters for the express purposes of availing the camera to infrared photography. That solution is great for infrared photography but renders the camera useless for normal visible light photography. So for a specialist, it’s excellent, but for someone who’d just like to dabble in the infrared spectrum, it’s not ideal. For that, it turns out there’s a solution that allows photographers to pursue easy infrared image capture without modifying their cameras. And it comes in the form of an iPhone.
Recent generations of iPhones (the 11 and 12, in particular) use LIDAR to aid in measuring depth and space and their front-facing lenses are sensitive to infrared light. This means if you place an IR filter over all three lenses on an iPhone 12 Pro Max, for instance, you can effectively capture infrared images. Here’s how.
For experimenting with iPhone infrared photography, I suggest starting with the simplest and most affordable approach. Sure, you could purchase a high-quality 52mm threaded infrared filter, but given the fact that it’s not going to thread onto the iPhone anyway, why not try a sheet filter? The Lee 87 polyester filter pictured here measures about 3×3 inches and can be had for under $20. The filter can simply be held or, better yet, taped to the iPhone or its case in order to cover all of the lenses and the LIDAR. If you’re using a circular threaded filter, the process works the same way, though that circular filter is likely to do a better job of blocking light leakage if well taped to the camera. In any case, look for a filter that blocks visible light up to approximately 720nm, which is in the near-infrared spectrum.
The iPhone’s native camera works fine for infrared capture, though because you’ve blocked out so much visible light, it will require night mode’s long exposures. In the examples shown here, made on a bright, lightly overcast day, the exposures lasted several seconds. That makes a tripod a necessity for more serious pursuits, though stabilizing against a structure can eke out a suitable exposure.
The resulting images will appear deep red. For best results, set your camera to capture RAW image files and enjoy the benefits of more post-processing control. As is true with a mirrorless or DSLR, RAW files offer the ultimate control over color, contrast and sharpness even after capture. Still, the trees photographed here were in-camera JPEGs and HEIC files and they still produce that effective IR look.
With the red files opened in Photoshop or Lightroom, you’ll simply want to convert to black and white and adjust the contrast, black point and white point until the result is visually pleasing.
You can open an image in Photoshop and use the Black and White adjustment layer to control the b/w conversion with color-specific sliders that dramatically impact the look of the conversion. You can also open that image in Photoshop and go into the Channels palette and isolate the red channel to end up with just the infrared information that came through to the camera’s sensor.
Again, just a few adjustments to deepen the blacks and brighten the whites will go a long way to making your iPhone infrared photography really pop, like the final image below.