The **ALV-4W41-R** is a high-performance, industrial-grade **Auto-Iris Varifocal Lens** manufactured by **Computar (CBC Group)**. It is specifically designed for security and surveillance applications using CS-mount cameras. --- ### 1. Key Technical Specifications The following table outlines the primary electronic and optical characteristics of the device: | Feature | Specification | | :--- | :--- | | **Mount Type** | CS-Mount | | **Focal Length** | 4.0mm – 10.0mm (2.5x Zoom) | | **Aperture Range** | F1.6 – Close | | **Iris Control** | DC Auto-Iris | | **Sensor Support** | 1/3" and 1/4" Format | | **Horizontal FOV** | 71.3° (Wide) – 28.7° (Tele) | | **Operating Temperature** | -20°C to +60°C | --- ### 2. Electronic Components & Functionality The "Electronic" aspect of this lens primarily refers to the **DC Auto-Iris system**. Unlike manual lenses, this part interacts directly with the camera's processing board. #### A. The Iris Drive (Galvanometer) Inside the lens, there are two miniature coils: 1. **Damping Coil:** Provides resistance to smooth out the movement of the iris blades, preventing "hunting" (flickering). 2. **Drive Coil:** Receives a varying DC voltage from the camera to physically open or close the iris blades. #### B. The 4-Pin Interface The lens connects to the camera via a standard 4-pin square connector. The pinout configuration typically follows this standard: | Pin Number | Function | Description | | :--- | :--- | :--- | | **Pin 1** | Control - | Damping Coil Negative | | **Pin 2** | Control + | Damping Coil Positive | | **Pin 3** | Drive + | Drive Coil Positive (Open/Close signal) | | **Pin 4** | Drive - | Drive Coil Negative (Ground) | --- ### 3. Operational Mechanism The ALV-4W41-R functions through a feedback loop: 1. **Light Sensing:** The camera's image sensor detects the level of incoming light. 2. **Signal Processing:** If the image is too bright, the camera sends a DC voltage to the **Drive Coil**. 3. **Mechanical Action:** The magnetic field generated by the coil moves the iris blades to a smaller aperture. 4. **Varifocal Adjustment:** While the Iris is electronic, the **Zoom** and **Focus** are manual adjustments made via thumb-screws on the lens barrel. --- ### 4. Summary of Benefits * **Aspherical Technology:** The "A" in the prefix often denotes aspherical lens elements, which reduce spherical aberration and provide sharper images at the edges. * **Neutral Density (ND) Filter:** Often integrated into the iris blades to allow for better performance in extremely bright sunlight. * **Reliability:** Designed for 24/7 operation in varying light conditions.