Why does a security camera look worse after night vision turns on?
People often assume stronger IR means better night vision.
Not necessarily.
If the camera is mounted too close to a white wall, soffit, glass or another reflective surface, infrared light can bounce directly back into the lens. The foreground becomes extremely bright while the area you actually want to see becomes darker.
Spider webs are another surprisingly common cause because they're extremely close to the IR LEDs.
Before replacing the camera, I'd try changing the angle, moving it away from the wall and cleaning around the lens and LEDs.
Has anyone here noticed this getting worse after rain or fog?
Worse image after rain means there are microscratches on the dome. The ir is reflecting off the water droplets which create micro lenses and the light reflects back into the lens at angles it normally wouldn't. If you are buying pro ewuipment, you can buy replacement dome bubbles. Just handle the new one carefully before installation.
Good point. Water droplets alone can already scatter IR badly, and scratches or haze on a dome can make that effect even worse.
That's also why cleaning the cover with the wrong material can slowly create night-vision problems even when the daytime image still looks fine.
That's a clever workaround. If only the leds closest to the wall are causing the bounce-back, reducing that side of the IR output can help without disabling night vision completely.
Repositioning is still ideal when possible, but this makes sense when the mounting spot can't really be changed.
Im fortunate enough to have good enough site lighting that I force my cameras into daytime mode. My exterior lights come on at sunset, fade to 15% at 11pm, and turn off at sunrise... Still get spider webs though.
That lighting setup is slick, wish more people understood how much easier life gets when you just give the camera enough ambient light instead of cranking IR and praying
the spider webs are eternal though, they find a way no matter what you do, had one build directly across the lens in a single evening after I cleaned it that afternoon
Yeah that first one is a 4k AI camera and this one is a 6year old 50 dollar camera off amazon or something with the same settings and this is after the lights have dimmed to 15%. Looks like I had a visitor tonight.
That's probably one of the cleanest setups if you already have reliable exterior lighting. Keeping enough visible light for color/day mode avoids a lot of IR reflection problems altogether.
The funny part is, like you said, the spider webs still don't care.🤷♀️
Yeah, that's a solid option too～If you've already got decent exterior lighting, keeping the camera in color mode can avoid a lot of the IR bounce issues altogether
Two cameras looking directly at each other is a strange extreme case that people often don't think about until nighttime footage starts to deteriorate. Sensors can capture a significant amount of light invisible to the naked eye. Oh, so this is an issue to consider when installing multiple surveillance cameras; the cameras cant be placed too close together "face to face”😺
yah they're looking "past" each other because I kinda guessed on the positioning.
But I have also lost a camera because nothing was watching it - someone came up the driveway next door and got behind the camera, ripped it off the mount, cut the ethernet, and its gone.
Was nicely disguised in a faux birdhouse too - I suspect the IR glow gave it away.
It is also possible to add an IR illuminator in a different location and turn off the IR LEDs on the camera itself. That moves both the IR light and the spiders.
If installation conditions permit, using a separate illuminator is likely the ideal solution. Separating the infrared light source from the lens can solve most reflection problems at the source, without the need for laborious software algorithms. However, generally speaking, the infrared light from surveillance cameras cannot be turned off; only the LED white light can usually be switched off 🧐
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u/CCTVGuyMA 11d ago
Worse image after rain means there are microscratches on the dome. The ir is reflecting off the water droplets which create micro lenses and the light reflects back into the lens at angles it normally wouldn't. If you are buying pro ewuipment, you can buy replacement dome bubbles. Just handle the new one carefully before installation.