Fogging in infrared camera night vision is a prevalent issue, yet the industry has struggled to find an effective solution. For instance, the EZVIZ cloud brand, owned by industry leader Hikvision, has encountered reports of fogging in its waterproof cameras.
What is Lens Fog?
The mist observed inside your camera is not fog; it's actually condensation. Condensation is the reverse of evaporation, where water molecules transition from a gas back into a liquid form rather than from liquid to gas as in vaporization.
The moisture accumulating inside your lens occurs due to significant shifts in air temperature or humidity. It can happen when transitioning from cold to warm environments, such as moving indoors after being outside, taking your camera from a cooler space like a hotel room into a hot and humid area, or when exposed to atmospheric conditions like rain, sleet, or mist from a waterfall.
Condensation typically occurs when the outer surface of your lens cools below the "dew point" of the air inside. The dew point marks the temperature at which the air inside the lens can no longer retain all of its water vapor, causing some to revert to liquid form. Consequently, water vapor condenses into moisture, resulting in beads and fogging on the internal components of the lens.
The Causes of Infrared Camera Fogging
The fogging of the camera lens isn't solely a camera-specific issue; it's also greatly influenced by the environmental conditions in which it's used.
Foggy Locations
There are primarily two areas prone to fogging: the inner lens and inner glass of the camera, as well as the outer glass cover of the camera.
Causes of Fog
The primary cause is often the combination of low temperatures and high humidity in the camera's operating environment. During nighttime operation, when the infrared camera is activated, the internal temperature of the device rises. This temperature differential, combined with high humidity in the air, can cause saturated water vapor to condense into fog or frost. This condensation adheres to the glass protective cover or inner lens of the camera, resulting in obscured imagery.
Fogging Solutions for Infrared Cameras
1.Internal Fogging
When moisture accumulates inside the camera housing, resulting in high humidity, internal fogging occurs. This moisture can originate from various materials used in the camera's construction, such as circuit boards, PCB boards, chip motherboards, and lenses, containing impurities and volatile substances. At night, when the camera's infrared function is activated, the internal temperature rises, causing these impurities and water vapor to evaporate and condense on the internal lens due to inadequate ventilation.
Potential Solutions
- Enhance defrosting circuits, introduce air holes, incorporate fans, or use desiccants to alleviate internal fogging temporarily.
- Emphasize strict quality control measures during manufacturing to eliminate impurities and volatile materials.
- Ensure proper alignment of the shading ring with the glass to prevent light leakage and refraction into the lens.
- Optimize production environments to maintain low humidity levels and extend drying times during assembly.
2. External Fogging
External fogging, while not directly related to internal mechanisms, can still compromise visibility. To address this issue:
- Install wipers or advanced invisible wipers with water-repellent properties on the camera's protective cover to effectively clear moisture and maintain a clear line of sight.
- Regularly inspect and maintain the camera's exterior surfaces to prevent moisture buildup and ensure optimal performance in humid or rainy conditions.
What if the Condensation Has Already Formed?
Despite taking preventive measures, condensation may still occur on the camera lens, especially during extreme weather conditions or sudden temperature changes. If condensation has already formed, it's essential to address the issue promptly to restore clear vision and prevent potential damage to the camera.
1. Allow Time for Natural Evaporation
In many cases, condensation will dissipate naturally as temperatures stabilize and humidity levels decrease. Allow the camera to remain powered off in a dry, well-ventilated environment, and monitor the lens periodically to observe any changes.
2. Use Silica Gel Packs
Silica gel packs are highly effective at absorbing excess moisture and accelerating the evaporation process. Place the camera in a sealed container with silica gel packs to help remove moisture from the lens and internal components. Ensure the camera is powered off and the battery removed to prevent damage.
3. Employ Gentle Heat
Applying gentle heat to the camera lens can help expedite the evaporation of condensation. Use caution when applying heat to avoid damaging sensitive electronic components. A hairdryer set to a low, cool setting or a warm cloth placed over the lens can be effective in gently warming the affected area.
4. Avoid Wiping the Lens
While it may be tempting to wipe away condensation with a cloth or tissue, this can potentially scratch the lens or push moisture further into the camera housing. Instead, allow condensation to evaporate naturally or use alternative methods to remove moisture as mentioned above.
5. Seek Professional Assistance
If condensation persists despite attempts to remove it, or if you suspect moisture has penetrated internal components of the camera, it may be necessary to seek professional assistance. Contact the manufacturer or a qualified technician for guidance on proper cleaning and maintenance procedures.
Conclusion
Preventing camera lens fogging at night requires a multifaceted approach, addressing both internal and external factors influencing moisture accumulation. By implementing proactive measures such as improving ventilation, enhancing waterproofing, and deploying effective moisture management solutions, users can minimize the impact of fogging on infrared camera performance, ensuring clear and reliable night vision imagery in diverse environmental conditions.
For over 20 years, BIT-CCTV, a trusted Tianjin supplier of CCTV cameras, has been dedicated to providing high-quality surveillance solutions. We specialize in the design, engineering, manufacturing, and sales of a wide range of CCTV surveillance equipment. Our product lineup includes pan-tilt heads/positioners, long-range laser PTZ cameras, IR thermal imaging PTZ cameras, dual-vision PTZ cameras, camera housing enclosures, mounting brackets, and accessories.
Committed to durability and reliability, our products are crafted from robust materials and undergo rigorous testing to ensure they can withstand continuous operation in challenging conditions. With a focus on meeting the diverse needs of our customers, we also offer custom pan-tilt solutions tailored to specific system and project requirements.
Our dedication to quality and innovation has earned us a reputation as a leading supplier in the industry. Our products have been deployed in over 40 countries across five continents, demonstrating their effectiveness and reliability in diverse environments. Trust BIT-CCTV for your surveillance needs and experience the difference our high-quality products can make.
Comments