Security Camera IR Reflection: How to Fix It

The camera looked sharp at handover, then the first night clip comes back as a milky haze, a glowing ring or a white blob over the doorway. Security camera IR reflection is the usual cause: the camera’s own infrared light bouncing off something close to the lens and back into it. This guide covers diagnosis and fixes in the order you would try them.

Why IR reflection washes out the night image

At night most cameras switch to monochrome and light the scene with infrared LEDs mounted beside the lens. The light that matters travels out, hits the subject and comes back. Anything that sends light back sooner, from much closer, competes with it, and the exposure drops so the rest of the scene goes grey.

Distance is the reason a small, close surface wins. Georgia State University’s HyperPhysics page on the inverse square law shows that light from a point source falls with the square of the distance: at 2 meters it is one fourth as strong as at 1 meter. As an illustration with assumed distances, an eave 0.3 m from the LEDs receives about (6 / 0.3)² = 400 times the infrared per square meter that a person 6 m away does, before reflectance.

Diagnose the glare before changing anything

Do the test after dark, with someone at the monitor or a phone on the live view, because the problem rarely shows in daylight.

On a dome, take the bubble off at night and watch the image. If the haze vanishes, the fault is the bubble or its seal.

Reseat the dome bubble and the foam ring

Inside most IR domes a foam or rubber ring sits around the lens and presses against the inside of the bubble. It stops LED infrared travelling sideways through the plastic into the lens. A ring that is missing, crushed or loose after a re-aim is the classic cause of IR bounce on a dome camera.

• Check the ring is present, round and undamaged, and sits flat against the bubble all the way around.
• After re-aiming the lens module, look again: tilting the module can pull the ring away from the cover on one side.
• Keep tilt inside the angle range on the camera’s installation guide; beyond it the lens can look through the edge of the bubble.

Clean, then check for scratches

Dust, pollen, fingerprints and water spots on the bubble scatter infrared back into the lens. Clean it with a soft, lint-free cloth and a cleaner the maker approves, without pressing grit across the surface. Handle the bubble by its edge during installation.

Scratches and weathering are a different matter. A hazed or scratched bubble scatters light permanently, and no cleaning fixes it. Order the replacement cover for that model. The trade-offs between styles are covered in our turret vs dome camera comparison; this guide stays with fixing the camera that is already on the wall.

Eaves, soffits and nearby walls in the frame

A camera tucked tight under an overhang, or mounted close to a corner, often catches the eave edge, a soffit, a gutter or the adjoining wall at the edge of its view. By the inverse square reasoning above, that surface is lit far more strongly than anything in the yard, and it flares.

1. Tilt down or pan away until the surface leaves the frame. Check at night.
2. On a varifocal camera, zoom in slightly to crop the eave out. Our varifocal vs fixed lens camera guide explains how focal length changes the field of view.
3. If the camera cannot be aimed clear, move it: a short bracket that stands it off the wall, or a mount a little lower on the fascia. The security camera mounting height guide covers how height and tilt affect what the camera sees.
4. Remove reflective clutter in front of the lens, such as cable ties or a downspout. Indoors, keep ceiling domes clear of smoke detectors and light fittings.

Spider webs and insects

Spiders build on camera housings and brackets, and insects land on the cover. A single strand across the lens catches the IR and glows; a web moving in the wind can trigger motion recording all night and fill storage with blank clips.

• Clean the cover, the bracket and the back box where spiders shelter.
• Where a camera keeps collecting webs, consider lighting the scene from elsewhere so the camera’s own LEDs can be turned down or off.

Security camera night vision glare through windows

Glass reflects some light at every angle. West Texas A&M University physicist Christopher Baird explains that ordinary glass reflects about 4% to 6% of light head-on, and 60% to 62% at a grazing angle of 5 degrees. With the IR LEDs only centimeters behind the pane, that small fraction is enough to bounce straight back into the lens, and the night image shows the window, not the yard.

For a camera inside a window:

• Turn off the built-in IR. With it off, the camera relies on light outside the glass.
• Press the lens as close to the glass as the mount allows, square to the pane, and shade the room light behind it.
• Add outdoor lighting or an external illuminator outside, so the scene is lit without the glass in the light path.

Turn off built-in IR and use an external illuminator

When the camera cannot be moved clear of a reflective surface, separate the light from the lens. A standalone IR illuminator mounted a little away from the camera lights the scene without lighting the bubble, the eave or the glass right in front of the lens. Turn the camera’s own IR off in its settings so the two do not fight. For powering it, the outdoor security camera power guide covers the options.

Use the camera’s IR level and smart IR settings too. Smart IR, where the camera offers it, lowers LED output when something comes close to the lens, so a face at the door is not burned out. A lower overall IR level also helps beside a wall.

Where to find cameras and accessories

The security cameras category lists cameras, and the recorders category lists NVRs and DVRs, both in the Security, Surveillance and Control division. For replacement covers, mounts and pricing, ask your sales representative through the Bursma contact page or the Grand Rapids area branch, or open a Bursma dealer account.

Frequently asked questions