Can infrared see in the dark?
Not in the way people often imagine. Infrared photography records near-infrared light, a part of the spectrum just beyond what our eyes see. It is not the same as thermal imaging, which records heat, and it is not a night vision device that amplifies light. A camera used for infrared photography still needs light to record an image. That light just happens to include wavelengths we cannot see.
At night, the question becomes whether there is enough near-infrared light in the scene. Sometimes there is, and the results can look striking. Often there is not, and exposures become long and noisy.
What infrared photography is
Digital camera sensors are sensitive to near-infrared, but manufacturers place a filter in front of the sensor to block most of it so that daytime colour looks normal. Infrared photography works either by adding a filter to the lens that blocks visible light, or by modifying the camera so the internal filter is removed or replaced. Infrared images are often converted to unusual colours or black and white, and foliage commonly looks pale in daylight. At night, results are different and depend heavily on the light sources.
What light is there at night?
Not all night light contains much infrared. In general:
- Incandescent and halogen lamps give off a lot of near-infrared.
- Older street lamps, such as some sodium types, may give some usable infrared, but this varies a lot by lamp type, so treat it as something to test.
- LED lighting typically emits little infrared, so many modern LED-lit streets give weak results.
- Moonlight reflects sunlight and includes some infrared, but it is faint.
This is the main reason infrared night photography can be hit or miss. A town changing to LED lighting can change what works. Test before you invest a whole evening.
What works
- A full-spectrum converted camera. With the internal filter removed, the sensor is far more sensitive to infrared than a stock camera, and you can fit different filters in front of the lens. This is widely described as the best option for night work.
- Shorter-wavelength infrared filters. Filters that pass some visible light along with infrared, often in the range of roughly 550nm to 720nm, let in more light and keep some colour. Very strict filters, such as 850nm, block so much that they are generally too dark for night scenes.
- Tripod and remote release. Exposures are long, so camera shake becomes a problem without a tripod.
- Incandescent-lit or mixed-light scenes, such as older commercial areas, parks near lit buildings, or places with warm lamps.
What does not work well
- Unmodified cameras with an infrared filter. The camera’s internal filter blocks most infrared, so you need very long exposures. In dim light this becomes impractical.
- Handheld shooting. Exposure times are too long.
- Moving subjects. Long exposures blur people and cars.
- Dark, LED-lit areas. There is little infrared to record.
- Expecting a night vision look. The image will look unlike what the eye sees, but it will not be a bright view of a dark scene.
Settings to try
Treat these as starting points. Your camera and light will differ.
- ISO: about 800 to 1600 is a common starting range, higher if you must and your camera handles noise.
- Shutter speed: long exposures, up to about 30 seconds, depending on the amount of infrared available.
- Aperture: a moderate to wide aperture, but test your lens, since some lenses show a bright “hotspot” in the middle of the frame in infrared.
- White balance: set a custom white balance for infrared, or correct it later in RAW.
- Focus: infrared focuses at a slightly different point from visible light, so lens focus scales can be off. Use Live View and check results.
Check the histogram, since bright highlights and window reflections can clip easily. For more general advice on exposure and ISO in the dark, see our night photography guide.
Best ISO for night photography in general
There is no single best ISO. Use the lowest ISO that gives you a sharp exposure. With a tripod that might be ISO 100 to 800. Handheld in dim light, higher values are often needed. Our article on night street camera settings describes handheld choices.
Editing infrared images
Infrared files often need a custom white balance and channel work to produce the colour you want. Many people choose black and white, which avoids the heavy colour casts. A tool that lets you swap colour channels can create false-colour effects. Expect some trial and error.
Should you try it?
Infrared night photography is a niche pursuit. If you already own a converted camera, trying it is cheap. If you do not, it is probably worth exploring ordinary night photography first, including lighting and stars, before paying for a conversion. Be realistic about the light sources near you, and do not assume infrared will reveal hidden detail in complete darkness.
A note on security cameras
Readers sometimes ask how to block a night vision or security camera. Those cameras usually rely on infrared illumination built into the camera, which is a different topic from photography. This article does not cover it, and anything involving other people’s cameras raises legal and privacy questions that depend on where you live.