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Description
The Pixfra Sirius range is perfect for:
- Bat surveys with potential roost features clustered in a smaller area
- Bat surveys of trees
- Bat surveys of distant structures, or where access does not allow close inspection, such as railway tunnels and bridges
- Nocturnal bird and mammal surveys
- Hunting
- Search & rescue
Manufacturer warranty information
The Pixfra Sirius Thermal Monocular is designed for professionals engaged in wildlife observation, ecological fieldwork, and monitoring, particularly in low-light or zero-light conditions. It offers high-resolution thermal imaging, long-range detection, and robust functionality tailored for nocturnal wildlife observation.
Unlike traditional optics that rely on visible light and are ineffective in darkness or poor visibility, thermal monoculars operate by detecting infrared radiation. The Sirius series is equipped with vanadium oxide uncooled focal plane detectors, offering pixel resolutions up to 640 × 512 and thermal sensitivity down to ≤18 mK@f/1.0. These specifications support precise detection of subtle temperature variations - crucial for identifying elusive or camouflaged wildlife.
The Pixfra Sirius range sits at the top of Pixfra’s thermal imaging lineup. Compared to the Pixfra Mile and Mile 2 series, Sirius models deliver extended detection distances (up to 2,600 m), higher image clarity, and a smoother viewing experience, aided by 50 Hz refresh rates. While the Mile and Mile 2 are effective for short- to mid-range use, the Sirius is intended for tasks requiring maximum resolution, range, and operational precision.
In challenging environments - dense vegetation, fog, or total darkness - the Sirius offers reliable thermal visibility, enabling non-intrusive monitoring that avoids disrupting natural behaviour.
All models in this range meet the requirements set out in best practice guidance for bat surveys. Please see the Thermal Imaging: Bat Survey Guidelines published by the Bat Conservation Trust for more advice on how to choose your thermal imaging equipment for bat surveys.
Specifications
| Feature | PFI-S435 | PFI-S635 | PFI-S650 | PFI-S650D |
|---|---|---|---|---|
| Detector type | Vanadium oxide uncooled focal plane | |||
| Effective pixels | 384 × 288 | 640 × 512 | ||
| Pixel pitch | 12 µm | |||
| Spectral range | 8–14 µm | |||
| Sensitivity (NETD) | ≤18 mK@f/1.0 | |||
| Focal length | 35 mm | 50 mm | 25 mm / 50 mm (dual lens) | |
| Focus control | Manual | |||
| Close focus | 3 m | 2 m (25 mm); 8 m (50 mm) | ||
| Aperture | F1.0 | F0.9 | F0.88 (25 mm); F1.1 (50 mm) | |
| Field of view | 7.85° × 5.89° / 13.7 × 10.3 m @100 m | 12.4° × 10° / 21.9 × 17.6 m @100 m | 8.8° × 7.1° / 15.4 × 12.3 m @100 m | 25 mm: 17.9° × 14.2° / 30.7 × 24.6 m @100 m; 50 mm: 8.8° × 7.0° / 15.4 × 12.3 m @100 m |
| Detection distance | 1,800 m | 2,600 m | 1,300 m (25 mm); 2,600 m (50 mm) | |
| Digital zoom | 1×, 2×, 4×, 8× | |||
| Mag | 3.68× | 2.41× | 3.45× | 1.72× (25 mm); 3.45× (50 mm) |
| Frame rate | 50 Hz | |||
| Display | 1920 × 1080 OLED (0.49") | |||
| Colour palettes | 6 | |||
| Storage | 64 GB | |||
| Calibration | Auto, manual, external | |||
| Hot spot trace | Yes | |||
| Wi-Fi hotspot | Yes | |||
| Video recorder | Yes | |||
| Snapshot | Yes | |||
| Battery type | Replaceable 18650 | |||
| Battery life | ≥7.5 h | ≥6 h | ||
| Power supply | 5 VDC / 2 A | |||
| Port | USB Type-C | |||
| Operating temp | –30°C to +55°C | |||
| IP rating | IP67 | |||
| Dimension | 194.3 × 54 × 65.4 mm | 213.1 × 73 × 83.4 mm | 223 × 61 × 71.4 mm | |
| Packaging size | 291 × 140 × 127 mm | |||
| Net weight | 421 g | 537 g | 537 g | |
Features
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High-resolution thermal sensors with up to 640 × 512 pixel resolution and ≤18 mK sensitivity for detecting small temperature differences
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Detection ranges up to 2,600 m, supporting observation of wildlife at extended distances without risking disturbance
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Multiple lens options, including a dual-lens model (S650D), for both wide-angle context and detailed close-up thermal imaging
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1920 × 1080 OLED displays and six thermal colour palettes to accommodate different environmental conditions and observation needs
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Digital zoom capability (1× to 8×) and hotspot tracing streamline the identification and monitoring of heat-emitting subjects
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Onboard 64 GB storage for video and still image capture, with Wi-Fi hotspot functionality for direct data transfer and analysis
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IP67-rated enclosures and operating tolerance from –30°C to +55°C, ensuring performance across diverse field conditions
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Powered by replaceable 18650 batteries for field flexibility and extended survey sessions
Additional information
The Pixfra Sirius range is well-suited to professionals working in ecological consultancy and conservation. It enables continuous observation in settings where traditional optical instruments are limited by light conditions or environmental obstructions. The longer focal lengths found on models in this range are better suited to survey of distant targets.
With features such as manual thermal focus, a broad operating temperature range, and environmental sealing, these devices perform reliably in remote and challenging field locations. Integrated recording capabilities support visual documentation of species presence, movement patterns, and site activity.
For further utility, users may wish to explore compatible thermal optics accessories, wildlife trail cameras, and portable field power kits.