Search and Rescue Thermal Cameras

Thermal imaging devices can support search-and-rescue teams operating in dark buildings, tunnels, collapsed structures, outdoor environments and other areas where visible-light observation is limited.

The thermal camera may be handheld, helmet-mounted, vehicle-mounted or integrated into a rescue robot or drone.

Infrared lenses for search-and-rescue equipment can be designed for:

• Locating people in dark or smoke-filled areas

• Searching collapsed or damaged structures

• Night-time rescue operations

• Tunnel and underground rescue

• Mountain and wilderness search

• Flood and disaster response

• Marine rescue

• Emergency inspection of hazardous areas

A wide-angle lens may be selected for short-range indoor search, while a longer focal length can support observation over a larger outdoor distance.

For mobile equipment, the lens size, weight and mechanical stability must be coordinated with the camera module, battery, display and protective housing.

Helmet-Mounted and Wearable Thermal Imaging Devices

Wearable firefighting equipment has stricter limitations on weight, size and installation space than conventional handheld cameras.

A helmet-mounted thermal imaging lens may require:

• Small outer diameter

• Short total track length

• Low optical and mechanical weight

• Wide scene coverage

• Fixed or athermalized focus

• Stable detector alignment

• Customized flange or threaded interface

• Compatibility with a miniature uncooled detector

Optical design must balance field of view, aperture, image quality, detector format and lens envelope.

IRLENS can evaluate compact custom lens assemblies for wearable and body-mounted thermal imaging systems when an existing catalogue lens does not fit the required mechanical space.

Thermal Imaging for Rescue Robots

Firefighting and rescue robots can enter areas that may be too hazardous for immediate human access. Thermal cameras installed on these robots can provide visual information about heat sources, obstacles and possible survivors.

Robot-mounted infrared lenses may need to support:

• Remote operation

• Fixed or motorized focus

• Wide-area scene observation

• Pan-and-tilt camera integration

• Vibration and movement

• Compact equipment housings

• Continuous operation

• Customized mechanical installation

For robots operating in confined indoor environments, a wide-angle LWIR fixed-focus lens may be appropriate. Larger platforms may use motorized-focus, dual-FOV or zoom lenses to observe targets at different distances.

The complete camera enclosure remains responsible for environmental sealing and physical protection. Lens specifications should be coordinated with the enclosure design during development.

Thermal Imaging for Firefighting Drones

Thermal drones can support fire-scene observation, wildfire monitoring, search and rescue and post-fire hotspot inspection.

An infrared lens for a firefighting drone must be selected according to the flight altitude, target size, detector resolution, required ground coverage and payload restrictions.

Typical drone applications include:

• Wildfire hotspot observation

• Search for missing persons

• Roof and building inspection

• Fire perimeter mapping

• Observation of inaccessible areas

• Post-fire residual heat inspection

• Emergency command support

A wider field of view provides greater scene coverage, while a longer focal length places more detector pixels on a smaller target.

For UAV integration, customers should provide the maximum lens weight, diameter, length and gimbal installation space. IRLENS can recommend a compact standard lens or evaluate a custom lightweight optical design.

Early Fire Detection Systems

Thermal imaging systems can also be installed for continuous monitoring of locations where abnormal temperature rise may indicate a developing fire risk.

Unlike handheld firefighter cameras used after an incident begins, early fire detection systems are normally fixed or PTZ monitoring systems designed to identify abnormal thermal patterns before visible flames become extensive.

Potential applications include:

• Warehouses

• Recycling and waste-storage areas

• Coal and biomass storage

• Conveyor systems

• Electrical facilities

• Battery storage areas

• Industrial production lines

• Chemical storage areas

• Forest and vegetation monitoring

• Logistics and material yards

The infrared lens collects thermal radiation from the monitored area and forms the image on the detector. The camera and software then evaluate temperature data or thermal patterns according to the system design.

A lens for early fire detection should be selected according to:

• Monitoring area dimensions

• Camera mounting position

• Minimum hotspot size

• Required detection distance

• Detector resolution and pixel pitch

• Temperature measurement range

• Fixed or PTZ installation

• Field of view

• Outdoor or indoor environment

• Required image coverage

Temperature measurement accuracy is a complete-system characteristic. The detector, calibration, lens transmission, camera electronics, software and environmental conditions must all be considered.

Industrial Fire Prevention

Industrial facilities may contain equipment, materials or processes that can generate abnormal heat before a fire develops.

Thermal monitoring systems can help inspect:

• Electrical cabinets and connections

• Motors and bearings

• Furnaces and heating equipment

• Conveyor components

• Stored combustible materials

• Battery packs and charging areas

• Chemical processing equipment

• Waste and recycling materials

For fixed monitoring of a defined area, a standard LWIR fixed-focus lens may provide a compact and repeatable solution.

For larger areas or systems requiring remote adjustment, a motorized-focus, dual-FOV or continuous zoom infrared lens may be considered.

IRLENS can work with fire-detection camera manufacturers to match the focal length, detector, F-number and mechanical structure to the monitoring system.

Wildfire and Forest Fire Monitoring

Thermal imaging systems can be installed on monitoring towers, vehicles, drones or mobile observation platforms to identify abnormal heat patterns in forests and vegetation areas.

Wildfire monitoring normally requires different optics from a handheld firefighter camera because the target distance and monitored area are much greater.

Possible lens configurations include:

• Medium- or long-focal-length fixed lenses

• Motorized-focus infrared lenses

• Dual-FOV lenses

• Continuous zoom LWIR lenses

• Cooled MWIR lenses for demanding long-range systems

Lens selection should consider terrain, camera height, minimum target size, observation distance, weather conditions, detector sensitivity and the required field of view.

IRLENS can evaluate standard and custom lens assemblies for fixed, PTZ, vehicle-mounted and UAV wildfire detection systems.

Selecting the Right Firefighting Infrared Lens

The final lens configuration should be selected from the complete camera requirements rather than from the application name alone.

Why LWIR Is Commonly Used in Firefighting Cameras

LWIR lenses operating in the long-wave infrared band are commonly paired with uncooled thermal detectors.

This combination can support compact camera architecture, relatively low power consumption and fixed-focus operation, making it suitable for handheld, wearable and portable firefighting equipment.

LWIR systems are frequently considered for:

• Handheld firefighter thermal cameras

• Helmet-mounted cameras

• Rescue robots

• Compact rescue drones

• Fixed early fire detection

• Indoor and outdoor thermal monitoring

MWIR lenses are more commonly associated with cooled detectors and may be selected for higher-performance or longer-range systems.

The correct spectral band depends on the detector, target temperature, required range, operating environment, system size and available power.

Available Firefighting and Rescue Lens Configurations

Athermalized Fixed-Focus Lenses

Athermalized lenses are designed to reduce focus variation over a specified temperature range.

They are suitable for handheld and fixed thermal cameras that must operate without manual focus adjustment.

Manual-Focus Infrared Lenses

Manual-focus lenses allow the user or equipment technician to adjust the image for different working distances.

They may be suitable for specialized inspection or lower-volume equipment where remote focus control is unnecessary.

Motorized-Focus Infrared Lenses

Motorized-focus lenses allow the camera system to adjust focus remotely.

They can be integrated into robots, PTZ equipment, vehicle-mounted systems and fixed monitoring cameras.

Dual-FOV and Multiple-FOV Lenses

Dual-FOV and multiple-FOV lenses provide two or more defined observation fields.

A wide field can support scene search, while a narrower field can provide additional image detail for a selected target.

Continuous Zoom Infrared Lenses

Continuous zoom lenses provide smooth changes in focal length and field of view.

They are more suitable for wildfire monitoring, remote fire detection and large observation platforms than for compact handheld firefighter cameras.

Custom Compact Lens Assemblies

For wearable cameras, miniature modules and specialized enclosures, IRLENS can evaluate custom optical and mechanical structures according to the detector and available installation space.

Key Parameters for Firefighting Camera Integration

Detector Model

Provide the detector manufacturer, model, resolution, pixel pitch and active image area.

Common detector information may include:

• Resolution

• Pixel pitch

• Active area

• Cooled or uncooled design

• Spectral response

• Required F-number

Field of View

The field of view determines how much of the scene the firefighter or operator can observe.

Handheld indoor cameras often require wider coverage, while fixed fire-detection cameras may need a narrower field for monitoring distant areas.

Focal Length

The required focal length should be calculated from the detector size, field of view, target dimensions and observation distance.

A longer focal length does not automatically produce a better system because it also reduces scene coverage.

F-Number

The F-number affects the amount of infrared radiation reaching the detector and influences lens dimensions and system performance.

The lens aperture must be matched to the detector and camera design.

Lens Size and Weight

For handheld, helmet-mounted, drone and robot systems, please specify:

• Maximum outer diameter

• Maximum total length

• Maximum weight

• Available back focal distance

• Mounting position

• Center-of-gravity restrictions

Focus Method

Specify whether the camera requires:

• Fixed focus

• Athermalized fixed focus

• Manual focus

• Motorized focus

• Dual field of view

• Continuous zoom

Mechanical Interface

Please provide the required mounting thread, flange structure, back focal distance and available installation space.

Custom housings and mechanical interfaces can be evaluated for OEM projects.

Operating Temperature

The lens design should be evaluated according to the expected operating and storage temperature range.

The customer should provide the actual system requirements rather than assuming that all firefighting lenses operate under the same conditions.

Front-Surface Protection

Anti-reflection coatings support infrared transmission. DLC and other hard protective coatings may be considered for suitable exposed optical surfaces.

Coating selection depends on the infrared material, spectral band, environmental exposure and required optical performance.

Environmental and Validation Requirements

Firefighting equipment manufacturers should provide their applicable requirements for:

• Temperature

• Humidity

• Vibration

• Shock

• Dust and water exposure

• Drop testing

• Chemical exposure

• Equipment cleaning

• Product certification

Compliance must be verified at the complete camera or equipment level according to the applicable test standard.

Custom Infrared Lens Development for Firefighting Equipment

When a standard lens cannot satisfy the detector, field of view, camera dimensions or operating requirements, IRLENS can develop a custom infrared lens.

Requirement Review

Confirm the camera type, detector, spectral band, field of view, focal length, F-number, operating distance and environmental requirements.

Optical Design

Optimize the optical structure according to detector coverage, image quality, relative illumination, distortion and available installation space.

Mechanical Design

Develop the lens housing, mounting interface, focus structure and other mechanical components.

Material and Coating Selection

Select suitable infrared optical materials and coating solutions according to the waveband and equipment environment.

Prototype Manufacturing

Produce engineering samples for imaging, mechanical and system-level evaluation.

Assembly and Inspection

Inspect optical components and mechanical parts, assemble the lens and evaluate agreed indicators such as image quality, focus and optical-axis consistency.

Pilot Production

Support a small production batch after the engineering sample has been approved.

Volume Production

Provide repeat manufacturing and batch supply for approved firefighting thermal camera and fire-detection equipment projects.

From Samples to Repeat Volume Supply

Firefighting camera manufacturers commonly begin with one or several samples to verify:

• Detector coverage

• Field of view

• Focus stability

• Image quality

• Mechanical installation

• Camera enclosure compatibility

• Temperature performance

• Production feasibility

After the lens has passed system testing, the approved configuration can move into pilot production and regular purchasing.

IRLENS combines optical design, mechanical design, infrared component processing, coating, assembly and inspection to support both custom development and repeat production.

Why Work with IRLENS?

• MWIR and LWIR infrared lens development

• Lenses for cooled and uncooled detectors

• Athermalized, manual-focus and motorized configurations

• Dual-FOV, multiple-FOV and continuous zoom options

• Compact lens development for handheld and wearable equipment

• Optical and mechanical structure design

• Spherical, aspherical, diffractive and off-axis component processing

• AR, DLC, hard protective, reflective and filter coatings

• Precision mechanical parts manufacturing

• Optical component inspection

• Infrared lens assembly and adjustment

• Imaging evaluation at different ambient temperatures

• Engineering samples and pilot-production support

• Repeat volume manufacturing

IRLENS works with thermal camera manufacturers and emergency-equipment developers to evaluate the complete lens requirements rather than simply supplying an isolated optical component.

Information Required for a Firefighting Lens Quotation

Send your detector specifications, camera dimensions and application requirements to IRLENS. Our engineering team will evaluate whether an existing lens can be used or whether a custom firefighting thermal camera lens is required.

Request a Custom Firefighting Lens Evaluation

Discuss Your OEM and Volume Production Project

Frequently Asked Questions

Which infrared lens is suitable for a handheld firefighter thermal camera?

Compact athermalized LWIR fixed-focus lenses are suitable for many handheld camera designs. The final selection depends on the detector, required field of view, camera dimensions, operating temperature and enclosure structure.

Can an infrared lens see through smoke?

Thermal imaging can provide useful visibility through many smoke-filled environments because it detects thermal radiation rather than visible reflected light. Performance still depends on smoke density, temperature, wavelength, target contrast, detector sensitivity and camera configuration.

Can the lens see through walls or solid objects?

No. Thermal cameras generally detect radiation from visible surfaces. They do not provide direct vision through ordinary walls or solid structures.

Can IRLENS customize a compact lens for a helmet-mounted camera?

Yes. Please provide the detector, required field of view, maximum diameter, total length, weight limit and mounting interface for evaluation.

Do you provide lenses for fire-detection drones?

Yes. Compact fixed-focus, athermalized and other infrared lens configurations can be evaluated according to the detector, flight altitude, target size, gimbal space and payload limit.

Do you provide long-range lenses for wildfire monitoring?

IRLENS offers medium- and long-focal-length fixed, motorized, dual-FOV and continuous zoom lens configurations. The correct option depends on the target distance, detector and observation platform.

Can the lens be used for temperature measurement?

An infrared lens can be integrated into a radiometric thermal imaging system, but temperature measurement performance depends on the complete camera, calibration, detector, electronics, software, lens transmission and operating environment.

Can we order engineering samples before mass production?

Yes. Samples can be used to evaluate optical performance, detector matching, mechanical installation and complete camera operation before pilot or volume production.

What information is required for a quotation?

Please provide the equipment type, detector model, resolution, pixel pitch, spectral band, field of view, focal length, camera dimensions, operating temperature and estimated quantity.