How to spot a night-vision camera by its infrared glow
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A camera that records in the dark needs light, and many covert cameras bring their own. They carry a small ring or cluster of infrared LEDs that flood the scene with light just past the red end of what people can see. The camera sensor picks it up and produces a grainy black-and-white picture of a room that looks pitch dark to you.
That built-in light is also a giveaway. Many phone cameras can see some infrared, which turns your phone into a simple infrared camera detector. This guide explains the two common LED types, how to test your phone before you trust it, how to run the check, and where it falls short.
850 nm and 940 nm: two kinds of night vision
Night-vision LEDs in consumer cameras mostly fall into two groups by wavelength.
Around 850 nm. These are brighter and give the camera a longer night range. They sit close enough to visible light that most people can see a faint, dull red glow from each LED when looking straight at them in a dark room. If you have ever noticed a ring of dim red dots on a security camera at night, those were probably 850 nm LEDs.
Around 940 nm. These are sold as no-glow or covert infrared. The eye sees almost nothing, even in full darkness. The trade-off is that camera sensors are less sensitive at this wavelength, so the LEDs light a shorter distance, and your phone will also show them more faintly.
Not every hidden camera has night vision. Many cheap pinhole cameras have no LEDs at all and simply record poorly in the dark. Others switch their LEDs on only when the room is dark, using a light sensor.
Why your phone can see it, sometimes
Camera sensors respond to near-infrared light naturally. Phone makers usually add a filter to block most of it, because infrared spoils colors in daylight photos. How strong that filter is varies by model and by camera. On many phones the rear camera filters heavily, while the front camera lets more infrared through, but this is a tendency rather than a rule.
That is why the first step is always a test with a TV remote. Most remotes send commands with an infrared LED, often in the 940 nm range, which makes them a good stand-in for the harder case. If your phone shows the remote's tip lighting up, it can likely see a night-vision camera's LEDs too. If it shows nothing on either camera, the infrared check will not work on that phone.
What the glow looks like
- A cluster or ring of small dots, often purple, pink or white on screen, arranged around a darker center where the lens sits.
- A single soft glowing point on a small device that has one LED.
- Steady light, not blinking. Night-vision LEDs stay on while the room is dark. A blinking light is more likely a status indicator.
- No matching visible light when you look at the same spot with your own eyes, especially with 940 nm LEDs.
What an infrared check catches and misses
It catches cameras that are actively lighting a dark room with infrared, even from across the room and even when the camera is on a network you cannot scan. It does not need line of sight to the lens itself, only to the LEDs, which are usually beside it.
It misses cameras with no infrared LEDs, cameras whose LEDs are off because the room is bright, cameras that rely on existing light, and weak 940 nm sources on phones with strong filters. It can also flag harmless sources that give off infrared, such as a remote in use, some alarm and proximity sensors, and security cameras the owner has disclosed. Pair it with a lens reflection check, covered in the lens finding guide, which works on cameras with or without night vision.
Where Candor fits
On Android, Candor's lens finder includes a front-camera infrared check designed for this search, alongside its flashlight-based reflection finder. Used together, the two help with both daytime and night-vision cameras that are within line of sight. The Wi-Fi and Bluetooth scans add a check that does not depend on light at all. There is no iPhone version; iPhone owners can run the same remote test and use the front camera in the built-in camera app.
Check a room for infrared night-vision LEDs
- Test your phone with a remotePoint a TV remote at the front camera, hold a button, and watch the screen. Repeat with the rear camera and use whichever shows the brighter glow.
- Make the room fully darkClose curtains and turn off every light, including bathroom and hallway lights. Many cameras only switch on their LEDs in darkness, so give them a minute.
- Turn slowly through the roomHold the phone at chest height with the chosen camera facing outward, and turn a full circle. Then repeat while aiming higher, toward ceiling corners and shelves.
- Stop on any glowLook for small purple, pink or white dots, especially in a ring. Note what object they sit on.
- Rule out known infrared sourcesCheck whether the glow comes from a disclosed security camera, an alarm sensor or another device with a normal reason to give off infrared.
- Inspect by daylightTurn the lights on and examine the object up close for a lens and a power source. If it points at a private area, cover it if safe, photograph it and report it.
What a phone check cannot find
- Cameras without night vision give off no infrared glow, so a dark-room infrared check says nothing about them.
- In a lit room, many cameras switch their infrared LEDs off, which makes a daytime infrared check unreliable.
- LEDs around 940 nm show up far more faintly on phone cameras, and some phones cannot see them at all.
Frequently asked questions
Can I see a hidden camera's infrared light with my eyes?
Sometimes. LEDs around 850 nm can give a faint red glow in a dark room when you look straight at them. LEDs around 940 nm are nearly invisible to the eye.
Why does my rear camera not show the TV remote?
Many phones filter infrared more heavily on the rear camera. Try the front camera instead. If neither shows the remote, that phone is not suited to infrared checks.
Do all hidden cameras have infrared?
No. Many small cameras have no night vision at all. That is why an infrared check should be paired with a lens reflection check and, where possible, a network scan.