Fixed Focal Length vs. Dual Field of View vs. Continuous Zoom: Key Differences in Infrared Lenses

24 Oct,2025

I. Core Concepts

Infrared Fixed Focal Length Lens: Features a single, fixed focal length and an unchangeable field of view. It boasts a simple structure and the most significant cost advantage.

Infrared Dual Field of View (FOV) Lens: Incorporates two preset fixed focal lengths (typically wide-angle + telephoto). It switches between them via mechanical or motorized means, enabling a transition between "Search" and "Close Observation" modes.

Infrared Continuous Zoom Lens: Allows for seamless, smooth continuous zoom in/out within a specific focal length range, providing a continuously variable field of view.

II. Core Differences Comparison Table

Feature / Dimension	Infrared Fixed Focal Length Lens	Infrared Dual FOV Lens	Infrared Continuous Zoom Lens
Observation Flexibility	Fixed perspective, no zoom capability	Two-level switching, limited flexibility	Seamless continuous zoom, no observation blind spots
User Experience	Requires platform movement or lens change	Brief image blur/target loss during switching	Smooth image transition, continuous target tracking
Scenario Adaptability	Single, fixed scenario	Adapts to two typical scenarios	Dynamic, complex scenarios; all-in-one capability
System Cost	Low individual lens cost	Balanced cost-performance trade-off	High individual lens cost, but potentially lower total system cost
Technical Complexity	Low	Medium	High

III. Application Scenarios

When selecting an infrared thermal imaging lens, your specific application scenario is the decisive factor.

Infrared fixed focal length lenses, with their advantages of simple structure, high reliability, and low cost, are the ideal choice for static scenarios such as fixed-point surveillance and standard industrial temperature measurement. They deliver excellent night vision imaging performance at a highly competitive price.

If your task requires flexible switching between a "wide-area search" mode and a "detail confirmation" mode, such as in border outposts or specific UAV payloads, the infrared dual FOV lens offers a perfect compromise. It strikes a balance between cost and functionality, covering both wide coverage and detail through two preset focal lengths, eliminating the need to carry multiple fixed lenses.

For complex, dynamic missions like high-end security reconnaissance, UAV inspection, and firefighting rescue operations, the infrared continuous zoom lens is the ultimate tool for comprehensive situational awareness, thanks to its irreplaceable smooth zoom capability. It enables seamless integration of target detection, tracking, and identification, ensuring no dynamic target is lost. Furthermore, its "one-lens, multiple-uses" characteristic simplifies system architecture and significantly enhances mission effectiveness and response speed in complex environments.