The large-aperture optical zoom imaging system can effectively meet the requirements of fast and stable acquisition of long range targets in large field of view and high observation resolution of target details.

The zoom system effectively coordinates the design requirements of these two aspects. By changing the zoom lens group to uniformly and continuously change the focal length of the optical system, it solves the defect that two and multiple optical lenses are easy to lose fast moving targets in a short time due to field switching.

The detection ability of the cooled infrared detector is 1 to 2 orders of magnitude higher than that of the uncooled type. The thermal imager of the medium-wave infrared camera currently used in the photoelectric theodolite is mainly the cooled type; In addition to the requirement of good imaging quality, the refrigeration infrared imaging system should also take into account the unique cold reflection, the efficiency of the cold diaphragm, and the infrared non-heating design of the refrigeration system. These factors undoubtedly increase the difficulty of the design.

The medium-wave infrared thermal imager developed by Xi'an Taihao Infrared Technology Co., Ltd. is composed of ultra-large aperture continuous zoom lens and ultra-high sensitivity detection components.

It has the following performance characteristics:

1. The large-aperture continuous zoom lens has 10X magnification, which can be used for long-distance target observation and large field of view search;

2. The detection module adopts intelligent image processing algorithms such as adaptive multi-background nonuniformity automatic correction technology, image noise filtering, image enhancement, automatic dimming, etc., to ensure high sensitivity and sharp video images;

3. Design means such as anti-vibration and shock, high and low temperature resistance, sealing treatment are adopted to ensure high reliability and high sealing of products;

4. The country's first large-aperture continuous zoom lens, with the largest lens aperture up to Φ 314mm；

5. The optical axis has good stability and consistency, and the change in the whole process is less than 2 pixels.