The Importance of PIR Sensors in Trail Cameras

January 7, 2025 ︱ By Willfine

When it comes to trail camera functionality, few components are as critical as the Passive Infrared (PIR) sensor. For businesses looking to develop or customize their own trail camera brand, a deep understanding of these sensors, especially ​​PIR sensitivity and PIR sensor field of view, is essential. PIR sensors are responsible for detecting motion and activating the camera, with their ​​sensitivity and detection coverage being key factors in ensuring the device reliably captures meaningful activity while minimizing false triggers.

This guide explores the role of PIR sensors in trail cameras, their design, and their applications. By tailoring PIR technology to your product, you can improve performance, enhance user experience, and meet diverse market needs.

What Is a PIR Sensor?

A Passive Infrared (PIR) sensor is an electronic device that detects infrared energy (radiant heat) emitted or reflected by objects within its field of view. Unlike active sensors, PIR sensors do not emit any energy but rely entirely on detecting changes in infrared radiation.

How It Works

All objects above absolute zero emit infrared energy. PIR sensors detect changes in the infrared radiation level when an object—such as an animal or a person—moves across the sensor’s field of view. These changes are converted into electrical signals, which trigger the camera to capture an image or video.

Souce: robocraze.com

Why It Matters

PIR sensors ensure the camera activates only when necessary, optimizing battery life, conserving storage, and reducing unnecessary captures caused by environmental factors.

How PIR Sensors Work with Trail Cameras

PIR sensors achieve their full potential when paired with complementary technologies like Fresnel lenses, which enhance their functionality in several ways:

Light Concentration

The Fresnel lens gathers infrared light from a broader area and focuses it onto the PIR sensor, improving detection sensitivity.

Expanded Detection Area

The lens divides the sensor’s field of view into multiple zones, allowing it to monitor a larger, more complex area.

Design Details

The small, curved plastic cover on trail cameras contains the Fresnel lens array. Each concentric ring in the lens directs infrared light to specific regions of the sensor, enabling precise motion detection.

Impact on Performance

While the Fresnel lens determines the detection angle, the PIR sensor itself dictates the detection range. Together, they define the camera’s ability to capture activity within its environment.

Customizable PIR Settings for Trail Cameras

To maximize a trail camera’s performance, many models offer adjustable PIR sensor settings. These settings allow users to tailor the camera to different environments and specific use cases.

Sensitivity Settings

PIR sensitivity can typically be adjusted to low, medium, or high levels based on the environment.

• High Sensitivity: Ideal for quiet areas with minimal movement, ensuring even small animals trigger the camera.
• Low Sensitivity: Useful in active environments to reduce false triggers caused by wind, foliage, or non-target animals.
• Tailored Flexibility: Sensitivity adjustments provide greater adaptability for diverse detection scenarios, enhancing user satisfaction.

Trigger Interval Settings

The PIR sensor’s trigger interval determines the time between consecutive activations.

• Short Interval (e.g., 5 seconds): Captures more frequent images of the same animal but can fill storage quickly.
• Long Interval (e.g., 5 minutes): Reduces redundant captures but may miss some activity.
• Recommended Setting: A balanced interval of 30 seconds works well for most users and can be adjusted based on specific requirements.

Types and Ranges of PIR Sensors

PIR sensors vary in detection range and application:

• Indoor PIR Sensors: Detection ranges from 25 cm to 20 meters.
• Outdoor PIR Sensors: Ranges extend up to 150 meters, suitable for open fields or large monitoring areas.
• Curtain PIR Sensors: Used for narrow, focused detection zones, ideal for specific trails or corridors.

Choosing the right PIR sensor depends on the intended use and the environment in which the trail camera will be deployed.

Detection Angle vs. Detection Distance: Practical Alignment

In trail cameras, the detection angle is primarily shaped by the PIR Fresnel lens, while the detection distance depends on the PIR sensor and its sensitivity. A wide angle increases coverage but also picks up more off-axis motion (e.g., wind-moved foliage). A narrower angle reduces side triggers and better aligns with what the imaging lens actually frames.

• Align PIR zones with framing: If the PIR “sees” beyond the camera’s frame, you’ll get “triggered but empty frame.” Slightly toe-in the camera or trim scene edges.
• Match to habitat: Dense cover → moderate angle + medium sensitivity; open lanes → wider angle + medium/high sensitivity.

Trigger Speed vs. PIR Delay vs. Trigger Interval

Trigger speed is the time from detection to the start of capture (aim for ≤0.5 s when possible). PIR delay (or recovery window) is the blackout after a capture before the next trigger can happen. Trigger interval is a scheduled minimum gap between consecutive captures to control redundancy.

Factor	What it does	When to favor it
Fast Trigger Speed	Reduces half-frames on fast passes	Trails, corridors, evidence-grade shots
Short PIR Delay	Captures sequences of the same event	Herd movement, multi-subject scenes
Longer Interval	Controls duplicates & saves battery	Feeders, high-traffic hotspots

Tip: Validate settings with a quick walk test at your target distance and speed.

Collaborate with Willfine for Custom Trail Camera Solutions

As a leading trail camera manufacturer, Willfine specializes in providing OEM/ODM solutions tailored to your brand’s requirements.

• Advanced PIR Integration: Our trail cameras feature customizable PIR technology, ensuring accurate motion detection and superior energy efficiency.
• End-to-End Customization: From sensor design to camera functionality, we help you create products that meet the demands of your target audience.
• Reliable Production and Delivery: With cutting-edge facilities and global logistics, we ensure seamless production and timely delivery of your trail cameras.

Partner with Willfine to design trail cameras that stand out in the market, delivering performance and reliability your customers can trust.