Why Is the Camera Image Still Foggy Even with a Defogging Function? Choosing the Wrong Defog, Heater, or Demist Function Won't Solve the Problem

In real-world surveillance camera applications, many customers have encountered this situation: The specification sheet clearly states that the camera has a defogging function, so why is the on-site image still foggy, blurry, and unclear? This issue is especially common at freezer entrances, low-temperature warehouses, food processing plants, cold chain logistics centers, and cold outdoor environments. In these applications, a blurry camera image is often not caused by a single factor. It may be due to fog in the distant environment, fogging or condensation on the front glass of the lens, moisture attachment, or even low temperatures that require the device itself to be heated in order to maintain stable operation. The problem is that several terms commonly found in camera specifications, such as Defog, Heater, and Demist, may all be understood as “defogging.” However, they are actually not the same thing. If these differences are not clearly understood during model selection, an awkward situation can easily occur: The specifications appear to include a defogging function, but when the camera actually fogs up on site, the image is still unclear. This article explains the differences between Defog, Heater, and Demist from a practical perspective, and also summarizes camera selection and installation recommendations for freezers, low-temperature environments, and high-humidity applications.