DIY IR Camera: How Cameras See Infrared and What to Build

An IR camera DIY project works when two things are true: the camera sensor is allowed to receive near-infrared light (its IR-cut filter is removed or switched out of the way), and something lights the scene with infrared, usually an LED lamp in the 850 or 940 nanometre range. Modding an old webcam or phone camera this way is a fun experiment, but it usually ruins daytime colour. If what you actually want is a camera that sees in the dark, a ready-made day/night security camera already does both jobs and switches automatically.

This guide explains how cameras see infrared, how to test what your own devices can do, what a basic home build involves, and when it makes more sense to use the camera you already own.

How a normal camera sees infrared

Almost every digital image sensor can detect some near-infrared light, the band just beyond red that human eyes cannot see. In daylight that extra light is a problem: it washes out colours, turns green plants pale and makes skin tones look odd. So manufacturers place a small filter, called an IR-cut filter, in front of the sensor to block it.

That filter is the whole story behind DIY infrared work:

• Fixed filter (most phones, most webcams): the filter is glued or pressed in place. The camera sees infrared only weakly, so it is poor in the dark even if you point an infrared lamp at the scene.
• Switching filter (most day/night security cameras): a tiny motor slides the filter in front of the sensor during the day and pulls it away at night. When it moves you often hear a soft click, and the picture changes from colour to black and white.
• No filter: some special-purpose cameras ship without one. They see infrared well day and night, but daytime colours look strange unless you add a filter in front of the lens.

The second half is light. Infrared cameras do not see heat; they see reflected near-infrared light. On a dark night there is very little of it, so an infrared night camera carries its own ring of infrared LEDs, or relies on a separate illuminator. If you want the deeper background on how the picture looks once infrared is in use, our guide to why night vision looks green on some devices and black and white on others covers the display side.

Test 1: can your phone see infrared?

Before you buy or take anything apart, run this two-minute test. You need a TV remote control that uses infrared (most older remotes do).

1. Open the camera app on your phone and switch to the front (selfie) camera.
2. Point the remote at the lens from close range and hold down any button.
3. Look at the screen. If you see a flickering white or purple dot at the tip of the remote, that camera passes some infrared.
4. Repeat with the rear camera. On many phones the rear camera shows a much weaker dot or none at all, because it has a stronger IR-cut filter.

What this tells you: a visible dot means the sensor responds to near-infrared, but only a little. It is a good demonstration, not a working night camera. To film a dark room with it you would still need a strong infrared source, and the image would be dim and noisy.

Test 2: what your security camera already does

If you own a Yoosee camera or any other day/night security camera, you already have a working infrared vision camera. Check it like this:

1. Open the app, go to live view and wait until it is dark. On models with a small light sensor on the front, covering it with a finger in a dim room usually triggers night mode sooner.
2. Watch for the picture to turn black and white. On most models you will hear a click as the IR-cut filter moves.
3. Look at the camera from a few steps away. You may see a faint red glow from the infrared LEDs if they are the 850 nanometre type. If you see nothing at all, the camera may use 940 nanometre LEDs, which are close to invisible.
4. Open the night or image settings. Menu names differ slightly by app version, but you will usually find an option such as automatic, colour or black and white. Leave it on automatic unless you have a reason to change it.

If the camera never switches, or stays stuck in black and white in daylight, that is a fault with the switching mechanism or the light sensor, not something a DIY mod will fix. Follow the steps in camera stuck in black and white during the day first.

What a basic DIY IR camera build involves

If you still want to build one, for a hobby project, a pet camera or simply to learn how it works, here is the honest outline. Details depend heavily on the device, so treat this as a map rather than instructions for a specific model.

Step 1: choose the right donor camera

• An old USB webcam is the usual choice. Cheap webcams often have a lens you can unscrew, which gives access to the filter.
• A phone camera is a bad candidate. The camera module is tiny, sealed and easy to break, and you lose the use of that camera for normal photos.
• A small board camera sold for electronics projects is often the cleanest option, because some versions are sold without an IR-cut filter. Check the listing carefully: the product description should say whether a filter is fitted.

Step 2: remove or bypass the IR-cut filter

On a typical webcam the filter sits between the lens and the sensor. It often looks like a small square or round piece of glass with a reddish or bluish tint when you tilt it.

1. Unplug the webcam before opening it.
2. Open the case and unscrew the lens. Note how far it was screwed in, because that sets the focus.
3. Locate the tinted filter. It may be on the back of the lens or in a holder above the sensor.
4. Remove it gently. If it is glued, some people replace the whole lens with one that has no filter instead of forcing it out.
5. Keep dust off the sensor. A single speck shows up as a dark blob in every frame.
6. Refit the lens and adjust focus, because removing the filter slightly changes where the image falls.

Expect to break something on your first try. Once the filter is out, the camera usually cannot be returned to normal and the warranty is gone.

Step 3: decide what you want to see

Without the filter, the camera now sees visible and near-infrared light together. That gives you two options:

• Leave it as is: daytime footage will look pink or washed out, but it works day and night.
• Add a visible-light-blocking filter over the lens: the camera then sees only infrared. This is the classic look for infrared photography and works well for night shots with an infrared lamp.

Step 4: add an infrared light source

This is where most DIY builds disappoint. A dark room has almost no near-infrared light, so the modded camera sees black until you add a lamp.

• 850 nanometre LEDs give a brighter picture on most sensors but show a faint red glow.
• 940 nanometre LEDs are near invisible to people but give a dimmer picture at the same power.
• Match the lamp's beam angle to the area you want to cover, and keep it close to the camera so the light falls where the lens points.

For a practical guide to choosing and placing a separate lamp, including glare and power, see adding an IR light for night vision. The same advice applies whether the camera is home-built or a security camera.

Step 5: test in real darkness

Test after dark, in the actual spot, not in a room with the lights dimmed. Look for three things: whether faces or objects are readable at the distance you care about, whether the centre is much brighter than the edges, and whether nearby surfaces bounce light back into the lens.

Safety and practical limits

• Electrical work: if your illuminator needs mains power, or you plan to wire anything outdoors, switch off power at the breaker and use a qualified electrician. Low-voltage plug-in adapters are the safer choice for a hobby build.
• Eye safety: high-power infrared LEDs can be bright even though you cannot see them. Do not stare into a powerful lamp from close range, especially 940 nanometre units where you get no visual warning.
• Ladders and roofs: if the build is going on an outside wall, use a stable ladder and a second person, or have an installer mount it.
• Weather: a webcam in a plastic box is not weatherproof. Condensation and heat break DIY outdoor builds quickly.
• Privacy: an invisible infrared camera still records people. Point it at your own property and check local rules before filming shared or public areas.

DIY build or day/night camera: how to decide

A home-built infrared camera makes sense when the goal is learning, photography or an indoor experiment. For security it usually loses to a camera designed for the job, for reasons that are easy to check:

• Automatic switching: a day/night camera gives you colour by day and infrared at night without any action from you. A modded webcam is stuck in one mode.
• Built-in illumination: the infrared LEDs are already aimed and powered to match the lens.
• Recording and alerts: a security camera records to a memory card or cloud service and sends motion alerts through the app. A webcam needs a computer running all the time.
• Housing: outdoor models are sealed against rain and dust; check the rating on the label for your model.

If you are deciding between infrared and colour at night rather than between DIY and ready-made, the trade-offs are covered in colour night vision vs infrared. Many cameras let you choose either mode, so you can test both in the same spot.

Troubleshooting a DIY or ready-made infrared camera

What you see	What it usually means	What to check
Picture is black at night	No infrared source, or the filter is still in place	Point a remote at the lens to confirm it sees infrared; add or switch on a lamp
Pink or purple daytime picture	Filter removed or stuck open	Expected on a DIY build; on a security camera, the filter mechanism may be stuck
Bright white haze at night	Infrared bouncing off a nearby wall, eave or window	Move the camera or lamp, and never film through glass with built-in LEDs on
Bright centre, dark edges	Lamp beam narrower than the lens view	Use a wider-angle lamp or move it further back
Blurry image after the mod	Focus changed when the filter came out	Turn the lens slowly while watching the live picture
Spiders and insects in every frame	Infrared LEDs attract them at night	Clean the lens and housing; move the lamp slightly away from the lens

When to get help

Stop and ask for help if:

• a security camera that used to switch between colour and black and white no longer does, even after you check the settings and the light sensor;
• the infrared LEDs on a ready-made camera do not glow at all and the night picture is black;
• you need to run new power cables outside or through walls;
• the camera has to go high on a wall or roof.

For a purchased camera, contact the seller or the support channel listed in your manual before opening it, because opening the housing can affect any warranty. For wiring and high mounting, use a qualified electrician or installer.

Frequently asked questions

Can I turn my phone into a night vision camera?

Not in any useful way. The remote-control test shows that a phone sensor picks up a trace of infrared, but the built-in filter blocks most of it, so even with a lamp the picture stays dim and noisy. Removing the filter from a phone module is far riskier than modding a webcam, and you lose the camera for normal photos.

Is an infrared camera the same as a thermal camera?

No. An infrared security or DIY camera sees near-infrared light reflected off objects, so it needs a light source such as infrared LEDs. A thermal camera senses heat given off by objects and works with no light at all, but it uses a completely different and much more specialised sensor.

Why does my infrared camera show a red glow on the LEDs?

It is normal. LEDs around 850 nanometres also give off a little visible deep-red light, which you see as a dim glow when you look straight at the camera. It does not mean the LEDs are failing, and the glow is usually only noticeable from in front and up close.

Can I see through clothing or walls with a modded infrared camera?

No. Near-infrared light does not pass through walls, and claims about seeing through clothing are misleading. A modded camera simply shows surfaces as they reflect infrared, which can change how some fabrics look, but it does not reveal what is behind them.

Will removing the IR-cut filter make my security camera better at night?

Usually not worth it. A day/night security camera already moves its filter out of the way at night, so removing it only spoils daytime colour. If night images are too dark, cleaning the lens, adjusting placement or adding an external infrared lamp helps far more.