The influence of infrared lens focal length on imaging effect

The focal length of the infrared lens refers to the distance from the center of the germanium glass lens to the imaging plane of the detector. For infrared night vision devices, the choice of focal length directly affects the imaging effect. Different focal lengths will produce different imaging effects. Therefore, choosing the right focal length is crucial for the detection, identification and clarity of the target.

For the same infrared detector type and specification, the larger the focal length of the infrared lens, the smaller the field of view and the smaller the imaging range. However, the detection distance and identification distance become farther, and the imaging becomes clearer. Therefore, when choosing the focal length of the infrared lens, the following points need to be considered: First, choose the appropriate focal length according to the size of the shooting scene and the distance of the target object; second, choose the target object with higher clarity according to actual needs; finally, ensure that the camera can adapt to changes in environmental factors, such as temperature, humidity, etc. Therefore, we need to choose the right lens according to the usage scenario to get the best visual experience.

In addition to field of view and clarity, focal length also affects the sensitivity of infrared night vision devices. Generally speaking, the longer the focal length, the higher the sensitivity. This is because long focal length can reduce the depth of the shooting scene, making the target object closer to the camera in the picture, thereby improving sensitivity.

Infrared thermal imaging technology is a technology for non-destructive testing based on infrared radiation emitted by the object being tested. Among them, imaging quality is one of the keys. The focal length of the infrared lens is an important parameter of the thermal imaging lens and has a direct impact on the imaging quality.

The focal length of infrared night vision devices is divided into short focal length, medium focal length and long focal length. The focal length of a short focal lens is generally less than 50 mm, which is suitable for shooting larger scenes such as forests and grasslands. Short focal length can capture a wider field of view, but the proportion of the target in the picture is smaller. The focal length of a medium focal lens is generally between 50 and 100 mm, which is suitable for the detection of small or medium-sized heat sources and defects, and is also suitable for detecting distant targets in day and night environments. The focal length of a telephoto lens is generally more than 100 mm, which is suitable for long-distance target analysis and detection, and for shooting smaller targets such as wild animals and human faces. The long focal length can magnify the target and make the picture clearer, but the field of view is relatively narrow.

When purchasing infrared night vision products, the choice of detector resolution and infrared lens focal length determines the spatial resolution, field of view, identification distance and other indicators, which affects the final imaging effect of the infrared night vision device. Therefore, it is particularly important to ensure that there is a suitable infrared lens focal length while having a high-resolution detector.

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