Useful tips
Camera glows at night: causes and solutions
Camera illumination at night manifests itself as white spots, light halos, a foggy veil or an almost completely unreadable frame. Most often, the problem is not related to a malfunction of the matrix, but to the reflection of infrared illumination, lens contamination, improper installation or too bright light sources. Accurately determining the cause helps restore detail without replacing equipment.
Why does the camera light up at night?
Most security cameras switch to black and white mode after dark and turn on IR LEDs. Infrared radiation is invisible to humans, but is well perceived by the sensor. If it is reflected from a nearby surface back into the lens, the automatic system reduces the exposure, which makes the distant part of the scene dark.
Typical causes of nighttime glow:
- Cobwebs, dust or water droplets. Particles near the lens reflect IR rays brightly and create blurry spots.
- Installation behind glass. The window glass reflects radiation back into the lens, so the built-in backlight actually illuminates the camera itself.
- Wall, cornice or ceiling in the frame. The nearby bright surface receives excess light, while the rest of the image is underexposed.
- The seal is damaged or incorrectly installed. In dome models, IR light can penetrate under the protective cap.
- Outdoor lighting. A flashlight, car headlights, or spotlight cause glare and overloading of certain areas of the matrix.
- Condensation inside the housing. Fogging creates a uniform milky haze and reduces contrast.
| Sign in the image | Probable cause | First priority action |
|---|---|---|
| White moving spot | Insect or spider web | Clean the housing and mounting area |
| Light halo around the edges | IR reflection in the dome | Check the seal and cap |
| A veil over the entire frame | Dirt, moisture or condensation | Clean and seal the housing |
| Bright wall, dark background | Bad viewing angle | Change camera direction |
| Light opposite the lantern | Backlight | Enable WDR or change position |
How to eliminate camera glare at night
First, clean the lens and protective glass with a soft microfiber cloth. Do not use abrasives: small scratches increase light scattering. You should also remove any cobwebs around the bracket and check for moisture inside the case.
The next step is to adjust the position. Nearby walls, gutters, branches, the edge of the roof, or the ceiling should not be in the frame. Sometimes it is enough to tilt the camera 5–10 degrees so that the infrared rays are not reflected back. To shoot through a window, the built-in IR illumination must be turned off and the lighting must be organized outside the room.
In the camera menu, it is worth checking the Smart IR, WDR, HLC and exposure settings. Smart IR automatically reduces the power of the diodes for close objects. WDR smooths out scenes with a large difference in brightness, and HLC muffles local sources such as headlights. Too long a shutter speed makes moving objects blurry, so it is corrected together with the signal amplification.
If the built-in illumination creates a stable halo, an effective solution would be a separate IR illuminator, mounted at a distance from the camera. Its angle should match the lens' field of view: too narrow a beam gives a bright center, while too wide a beam reduces the useful range.
When is a technical inspection required?
Service diagnostics are appropriate if the glow does not disappear after cleaning, changing the angle, and turning off the IR illumination. The cause may be a faulty IR filter, broken tightness, degradation of the protective glass, or incorrect operation of the exposure automation. To check, it is useful to compare frames with the IR diodes turned on and off: if the haze disappears, the source of the problem is almost certainly related to the reflection of infrared light.
Practical advice: Evaluate the result at night after final editing - the daytime footage does not show the reflection of IR illumination, condensation, and the influence of external lights.