Principle and Characteristics of Electric Zoom Lens 

Principle and Characteristics of Electric Zoom Lens 

Introduction to the Principle:

1. Definition: An electric zoom lens refers to a type of advanced lens that utilizes electric motors, integrated control cards, and control software to adjust the lens's zoom ratio. The zoom can be observed in real-time on a computer screen to achieve precise focus and obtain the clearest image. These lenses are equipped with automatic alarm protection to prevent mechanical failures.

2. Types: There are two types of electric zoom lenses:

   • Two-variable lens: It has adjustable focus (Fcous) and focal length (f), controlled by electric motors, while the aperture (IRIS) is automatically controlled by a camera signal.
   • Three-variable lens: In this type, all three parameters—focus, focal length, and aperture—are adjusted by electric motors. Generally, two-variable lenses perform slightly better than three-variable lenses, with slightly higher prices.

Characteristics:

1. Manual Aperture Lens: This type is suitable for environments with stable lighting conditions, such as indoors.

2. Automatic Aperture Lens: This type is used in environments with varying lighting conditions, such as outdoors.

3. Standard and Wide-angle Fixed-focus Lenses:

   • Wide-angle lens: Ideal for monitoring broader angles at shorter distances.
   • Standard lens: Suitable for moderate distances and angles.

4. Zoom Lens Types:

   • They are categorized by their zoom factor, typically 10x, 6x, and 2x.
   • Another categorization is based on control: manual zoom and electric zoom (with electric or automatic iris).

5. Sensor Compatibility: Zoom lenses are generally designed for specific sensor sizes, like 1/3", 1/2", or 1".

Principles for Selecting Zoom Lenses: The lens's specification should not be smaller than the camera's. For instance, a 1/2" lens can be used with a 1/3" camera, but a 1/3" lens cannot be used on a 1/2" camera. This compatibility rule is crucial to ensure optimal performance and imaging quality.

Understanding these principles and characteristics of electric zoom lenses will allow you to choose the right lens for your specific application, whether it be in surveillance, inspection, or industrial imaging.