The daytime footage is sharp and the night footage is a white haze, or a bright blob in the centre with darkness around it, or so blurry that a person is unidentifiable. Night vision problems are almost always about where the infrared light is going rather than about the camera sensor.
The short answer
The most common cause is infrared light reflecting straight back into the lens, from a wall, a window, a soffit or the camera’s own housing. Never point an infrared camera through glass. Move the camera away from nearby surfaces, and clean the lens housing, because spider webs across the lens are the second most common cause and they build up fast.
How night vision works and why it fails
The camera switches to a monochrome sensor mode and illuminates the scene with infrared LEDs, which your eye cannot see. Anything close to the camera reflects that light straight back, and because it is much closer than your actual subject, it appears enormously brighter. The camera exposes for that reflection and everything beyond it goes black.
That single mechanism explains almost every night vision complaint:
- Through a window: the glass reflects nearly all the infrared back. Total white-out.
- Under a soffit or close to a wall: the surface lights up and the scene beyond is underexposed.
- A spider web across the lens: the web is centimetres away and blazes white.
- Rain or snow: each drop reflects, producing a storm of bright specks.
- A dirty lens cover: dust and water spots scatter the light back into the lens.
Never point an infrared camera through glass
If a camera is inside looking out of a window, the infrared reflects off the glass and blinds it. Either mount it outside, or turn the infrared off and rely on external lighting.
Clean the lens and the housing
Wipe the dome or lens cover with a microfibre cloth. Look for spider webs and clear them. Infrared attracts insects, insects attract spiders, and a web across the lens ruins every night image.
Move the camera away from nearby surfaces
At least thirty centimetres of clearance in front of and around the lens. A camera tucked under a soffit or against a wall is lighting that surface rather than the scene.
Check for a protective film left on the lens
It happens more often than you would expect. A thin film left on the dome from installation scatters infrared badly while looking almost invisible.
Angle it slightly downward
This keeps nearby walls and the sky out of frame, reduces glare, and puts the infrared where you want it: on the path people walk.
Add a separate infrared floodlight
The best fix for a camera whose own illuminator causes problems. Mount the light a few metres from the camera and turn the camera’s own infrared off. Because the light no longer comes from beside the lens, reflections stop coming straight back, and insects gather at the light rather than in front of the camera.
Consider a spotlight camera instead
Cameras with a visible white light produce colour footage at night, which is far more useful for identifying people and vehicles than monochrome infrared. They also deter, which infrared does not.
Check the infrared cut filter is switching
You should hear or see a faint click as the camera switches to night mode. A filter stuck in the wrong position gives washed-out day footage or useless night footage, and it is a mechanical fault.
Separating the infrared light from the camera is the single most effective change available. Mounting an infrared floodlight a few metres away and disabling the camera’s own illuminator eliminates reflection glare, dramatically improves the image, and stops the nightly insect storm that triggers false alerts. It is the fix that turns unusable night footage into usable footage.
Blurry rather than washed out
If the image is dark and blurry rather than white and glaring, the causes are different:
- Not enough infrared reach. The illuminators on most consumer cameras cover perhaps ten metres. Beyond that the scene is simply unlit.
- Motion blur. Night mode uses a longer exposure, so anything moving smears. This is inherent and it is why identifying a moving person at night is hard on any consumer camera.
- Condensation inside the housing. A seal has failed and moisture is fogging the lens from the inside. Usually needs replacement.
- A scratched or clouded dome. Plastic domes degrade in sunlight over years, and replacement domes are sold separately for many cameras.
Condensation inside the lens housing means the weather seal has failed. Left alone, moisture corrodes the electronics and the camera fails entirely. If you can see fogging from the inside, treat it as a warranty claim or a replacement rather than something that will dry out.
Realistic expectations
Consumer infrared night vision is good for seeing that something happened and roughly where. It is poor at identifying faces at distance, reading number plates, or capturing anything moving quickly. That is a limit of small sensors, long exposures and modest illumination rather than a fault with your camera.
If identification at night genuinely matters, a spotlight camera producing colour footage, or good external lighting with the infrared turned off, is a substantially better approach than buying a camera with a bigger infrared specification.
Why is my night footage completely white?
Infrared light reflecting straight back into the lens, usually from glass, a nearby wall, or a spider web. Never point an infrared camera through a window.
Why do spiders keep building webs on my camera?
The infrared illuminator attracts insects and the insects attract spiders. Moving the light source away from the camera largely solves it.
How far does night vision reach?
Typically around ten metres on consumer cameras. Beyond that the scene is unlit regardless of the sensor, which is why a separate floodlight helps so much.
Why is moving footage blurry at night?
Night mode uses a longer exposure, so anything moving smears. It is inherent to the technology rather than a fault, and it is why identifying people at night is hard.
Is a spotlight camera better than infrared?
For identifying people and vehicles, considerably, because colour footage carries far more information than monochrome. It also deters, which invisible infrared does not.
The bottom line
Never point an infrared camera through glass, and give the lens clearance from nearby surfaces, because reflection is the cause of most night vision problems. Clean the housing regularly, since webs build up faster than you would believe. And if night footage genuinely matters, separate the infrared light from the camera or switch to a spotlight camera, which is a far bigger improvement than any specification upgrade.
