Making an infrared camera work effectively through glass, particularly security cameras with built-in IR night vision, presents a challenge because standard glass blocks or significantly reduces the transmission of the near-infrared light used by these illuminators. This often results in poor image quality, glare, and reflection when the IR LEDs bounce light off the glass surface.
However, you can improve the performance of a camera when filming through glass by implementing strategies that manage light and minimize reflection, often by avoiding the use of the camera's internal IR illuminators.
Here are practical steps based on common techniques and the provided references:
Addressing Challenges When Using a Camera Through Glass
Using a camera, especially one with IR capabilities, to look through a window requires addressing issues like reflections and glare. Standard window glass is highly reflective to the near-infrared light emitted by most security camera IR LEDs. This means the camera's own light bounces back into the lens, washing out the image.
The strategies below focus on mitigating these issues, enabling the camera to capture clearer images through the glass barrier.
| Challenge | Solution Based on References | Benefit |
|---|---|---|
| Glare and reflections | Place camera closer to the glass | Reduces angle for internal reflection |
| Internal light reflection | Turn off status lights | Eliminates source of internal reflection |
| Lack of external night lighting | Use motion-activated lights (external) | Provides visible light outside, bypassing IR reflection issue |
| Reflection off the glass surface | Put it somewhere darker (inside) | Minimizes light reflecting off the internal glass surface |
| IR reflection off glass | Disable the camera's built-in IR illuminator | Prevents the main source of glare/washout |
Practical Steps to Improve Camera Performance Through Glass
To maximize your camera's effectiveness when filming through glass, consider these actions:
- Place the Camera Closer to the Glass: Positioning the camera lens as close as possible to the glass pane helps minimize the gap where light can reflect and cause glare. This reduces the angle at which internal lights or the camera's own status lights can bounce off the glass and into the lens.
- Turn Off Status Lights: Many cameras have small LED indicator lights that show power or activity status. These lights, even if small, can cause reflections off the glass, especially at night. Disabling these lights in the camera settings, if possible, or covering them can help improve image clarity.
- Use Motion-Activated Lights: Since the camera's built-in IR is problematic through glass, relying on external visible light is often the best solution for night vision. Install motion-activated floodlights or standard outdoor lighting outside the window to illuminate the area the camera is monitoring. This provides clear, full-color or black-and-white images without needing the camera's IR.
- Put it Somewhere Darker: Ensure the internal environment around the camera is as dark as possible. Any light source inside the room can reflect off the glass surface and interfere with the camera's view outside. Turn off indoor lights in the camera's vicinity.
- Disable the Camera's Built-in IR Illuminator: This is a crucial step. The primary reason cameras fail to see clearly through glass at night is the reflection of their own infrared light off the glass. By disabling the IR LEDs in the camera settings, you eliminate this source of glare and washout, allowing the camera to rely on external lighting instead.
By implementing these techniques, you can significantly improve the quality of video captured by a camera looking through glass, effectively making it "work" in a scenario where its built-in IR night vision would otherwise fail.
