Key Takeaways

• IR corrected lenses eliminate focal plane offset between visible and infrared light, ensuring sharp imaging in both day and night conditions without re-focusing.
• TOWIN’s IR-corrected CS-mount lenses feature high resolution (3MP-8MP), large apertures (F1.2-F1.5) and wide compatibility with 1/1.8″, 1/2.3″, 1/2.7″ sensors for diverse surveillance needs.
• IR correction technology resolves common issues like blurring, color distortion and “focus shift” in low-light/infrared environments, critical for 24/7 security monitoring.
• TOWIN offers both fixed and varifocal IR-corrected lenses, optimized for wide-angle, medium-range and long-range surveillance scenarios with IR correction as a standard feature.
• Selecting the right IR-corrected lens depends on sensor size, focal length requirements, resolution needs and application scenarios (indoor/outdoor, short/long distance).

Introduction

24/7 day/night surveillance has become a core demand for security systems across commercial, industrial and residential sectors. Traditional non-IR-corrected lenses suffer from focal plane shift when switching between visible light (day) and infrared light (night), leading to blurry images, lost details and ineffective monitoring. IR-corrected lenses address this pain point by integrating specialized optical design and material technology, making them an indispensable component for high-performance surveillance cameras.

As a professional optical lens manufacturer, TOWIN Optics has developed a full range of IR-corrected CS-mount lenses, engineered to deliver consistent, high-quality imaging in all lighting conditions. This article explores the working principle, core benefits and practical applications of IR-corrected lenses, and provides a comprehensive selection guide for TOWIN’s IR-corrected lens series.

The Working Principle of IR-Corrected Lenses

IR-corrected lenses are designed to solve the fundamental optical problem of chromatic aberration and focal plane offset between visible light (400-700nm) and near-infrared light (700-950nm). Here’s how the core technology works:

• Special Optical Glass & Lens Design: Adopting LD (Low Dispersion) optical glass and ED (Extra-low Dispersion) lens technology to minimize the refraction difference between visible and infrared light, ensuring both light bands converge on the same focal plane.
• Multi-Layer Anti-Reflective Coating: A specialized coating increases the transmittance of infrared light (up to 95%+) while reducing glare and reflection in strong light, optimizing imaging in both bright and dark environments.
• Fixed Focal Plane Calibration: Factory-calibrated for both visible and infrared light, eliminating the need for manual re-focusing when the camera switches between day/night modes.
• CS-Mount Standardization: TOWIN’s IR-corrected lenses use the industry-standard CS-mount (flange focal distance 12.526mm), ensuring seamless compatibility with most CCD/CMOS surveillance cameras on the market.

Core Difference: Standard Lens vs. IR-Corrected lenses

The Core Impact of IR-Corrected Lenses on 24/7 Surveillance Imaging

IR-corrected lenses transform the performance of day/night surveillance systems by resolving the key limitations of traditional lenses. Their impact spans four critical dimensions:

1. Consistent Sharpness Across All Lighting Conditions

• Eliminates “focus shift” when the camera activates IR LEDs at night, ensuring the same level of sharpness for license plates, facial features and object details in both day and night.
• TOWIN’s large-aperture IR-corrected lenses (F1.2-F1.5) further enhance low-light performance by capturing more light, ideal for dark environments with no ambient light.

2. Elimination of Color Distortion and Image Degradation

• Special optical coating and glass material reduce chromatic aberration, preserving natural color reproduction in daylight and clear monochrome imaging in infrared mode.
• Avoids common issues like edge blurring, ghosting and flare in non-IR-corrected lenses, improving overall image quality for video analysis and evidence collection.

3. Extended IR Monitoring Range

• High infrared light transmittance allows IR LEDs to cover a longer distance (up to 2x that of non-IR-corrected lenses), expanding the surveillance coverage of outdoor cameras.
• TOWIN’s long-range varifocal IR-corrected lenses (e.g., 5-50mm) maintain clear imaging even at maximum zoom, critical for perimeter and large-area monitoring.

4. Reduced Maintenance and Operational Costs

• Factory-calibrated focal plane eliminates the need for on-site re-focusing after installation, saving labor costs for system deployment and maintenance.
• Durable optical design and multi-layer coating ensure long-term performance, reducing the need for lens replacement due to imaging degradation.

Practical Performance Comparison Across Different Surveillance Scenarios

IR-corrected lenses deliver distinct performance advantages over non-IR-corrected lenses in real-world surveillance scenarios. Below is a side-by-side comparison of key use cases, with TOWIN’s IR-corrected lenses as the reference standard:

1: Indoor Retail/Office Surveillance (Short-Range, Wide-Angle)

• Requirements: 180° wide coverage, clear imaging of human movement, low-light performance for night closing.
• Non-IR-Corrected Lenses: Blurry corners at night, lost details in dark aisles, frequent focus adjustment needed.
• TOWIN IR-Corrected Lenses (e.g., CS0412312F8 4mm): 145° diagonal FOV (1/2.3″ sensor), 8MP high resolution, F1.2 large aperture, sharp imaging of all areas 24/7 with no re-focusing.

2: Outdoor Perimeter Monitoring (Medium-Range, Varifocal)

• Requirements: Adjustable focal length (2.8-12mm), clear imaging of fences/gates, IR performance for night patrols.
• Non-IR-Corrected Lenses: Focus shift at zoom, blurry IR imaging at 12mm, poor detail capture of distant objects.
• TOWIN IR-Corrected Lenses (e.g., CCL1272812AMPR1 2.8-12mm): 113°~28° adjustable HFOV, DC auto iris, 3MP resolution, consistent sharpness at all focal lengths for day/night perimeter protection.

3: Long-Range Industrial/Logistics Surveillance (50mm+ Zoom)

• Requirements: Long-distance monitoring (50m+), clear imaging of vehicles/ cargo, resistance to harsh outdoor conditions.
• Non-IR-Corrected Lenses: Severe blurring at maximum zoom, ineffective IR coverage, distorted details of distant objects.
• TOWIN IR-Corrected Lenses (e.g., CCL1270550AMPR 5-50mm): 50.9°~6.2° HFOV, 1.5m minimum object distance, IR correction for long-range IR imaging, ideal for logistics yards and industrial parks.

4: High-Resolution Security for Public Areas (1/1.8″ Sensor)

• Requirements: Large sensor compatibility, high detail capture, low-light performance for busy public spaces.
• Non-IR-Corrected Lenses: Mismatched with large sensors, color distortion in daylight, blurry IR imaging at night.
• TOWIN IR-Corrected Lenses (e.g., CS361111815A3 3.6-11mm): 1/1.8″ sensor support, F1.5 low-light aperture, 113°~46° HFOV, optimized for high-end cameras in malls, stations and airports.

Performance Comparison Summary Table

TOWIN IR-Corrected Lenses: Full Series for Diverse Needs

TOWIN Optics offers a comprehensive range of CS-mount IR-corrected lenses, including fixed focal and varifocal options, optimized for 3MP-8MP resolution and 1/1.8″~1/2.7″ sensors. All lenses feature IR correction as a standard feature, with large apertures (F1.2-F1.5) for low-light performance and manual/auto iris for flexible light control. Below is the detailed specification of TOWIN’s flagship IR-corrected lens models:

TOWIN IR-Corrected Lens Core Series Specification

All TOWIN IR-corrected lenses share the following core strengths:

• 100% IR Corrected: Factory-calibrated for visible/IR light, no day/night focus shift.
• CS-Mount Standard: Flange focal distance 12.526mm, compatible with most surveillance cameras (Hikvision, Dahua, etc.).
• Low Light Optimization: Large apertures (F1.2-F1.5) for superior performance in dark environments.
• Durable Design: Multi-layer coating and high-quality optical glass for long-term outdoor/indoor use.
• Easy Installation: Manual focus/zoom with clear markings, quick deployment for security systems.

How to Select the Right TOWIN IR-Corrected Lens: A Complete Selection Guide

Selecting the optimal IR-corrected lens depends on 4 key factors: sensor size, resolution requirement, focal length/FOV needs and application scenario. Follow this step-by-step guide to make the right choice:

1: Confirm the Camera Sensor Size

• 1/1.8″ Sensor: Choose CS361111815A3 (3.6-11mm) – optimized for large sensors with high detail capture for high-end surveillance.
• 1/2.3″/1/2.7″ Sensor: Choose fixed focal models (CS0412312F8 4mm, CS1212312F8 12mm) for 8MP high resolution, or varifocal models (CCL1272812AMPR1 2.8-12mm) for medium-range flexibility.

2: Determine Resolution Requirement

• 8MP High Resolution: Select CS0412312F8 (wide-angle) or CS1212312F8 (fixed medium-range) – ideal for scenarios requiring ultra-clear details (license plates, facial features).
• 3MP/4MP Standard Resolution: Choose varifocal models (CCL1272812AMPR1, CCL1270550AMPR, CS361111815A3) – cost-effective for general surveillance with reliable performance.

3: Select Focal Length Based on Surveillance Distance/FOV

• Ultra-Wide Angle (Indoor/Short-Range): 4mm (CS0412312F8) – 105° HFOV for 180° indoor coverage (retail, offices).
• Medium-Range (Outdoor Perimeter): 2.8-12mm (CCL1272812AMPR1) – adjustable FOV for fences, gates and small outdoor areas.
• Long-Range (Industrial/Logistics): 5-50mm (CCL1270550AMPR) – 50mm maximum zoom for long-distance monitoring (yards, industrial parks).
• Medium-Range Large Sensor: 3.6-11mm (CS36111815A3) – optimized for 1/1.8″ sensors in public areas (malls, stations).

4: Choose Iris Type Based on Light Variability

• Fixed Iris: For environments with stable light (indoor offices, retail with constant lighting) – CS0412312F8, CS1212312F8.
• DC Auto Iris: For environments with large light changes (outdoor, open spaces) – automatically adjusts aperture for consistent imaging – CCL1272812AMPR1, CCL1270550AMPR, CS361111815A3.

Quick Selection Flowchart

Quick Selection Flowchart

Key Applications of TOWIN IR-Corrected Lenses

TOWIN’s IR-corrected CS-mount lenses are widely used in all 24/7 surveillance scenarios across industries, thanks to their compatibility, performance and durability. The main application areas include:

• Commercial Retail: Malls, supermarkets, convenience stores – wide-angle 8MP lenses for full indoor coverage and night security.
• Industrial & Logistics: Factories, logistics yards, warehouses – long-range varifocal lenses for perimeter and cargo monitoring.
• Public Infrastructure: Stations, airports, parking lots – large sensor lenses for high-detail capture of busy public areas.
• Residential & Community: Gated communities, apartment buildings – medium-range varifocal lenses for outdoor perimeter and entrance monitoring.
• Corporate & Office: Office buildings, co-working spaces – wide-angle fixed lenses for indoor area coverage and night security.
• Outdoor Public Safety: Parks, roads, street corners – auto iris varifocal lenses for adaptive performance in changing outdoor light conditions.

FAQs

CS mount IR corrected CCTV lens

Conclusion

IR-corrected lenses are the cornerstone of high-performance 24/7 day/night surveillance systems, resolving the core issue of focal plane shift and delivering consistent, sharp imaging in all lighting conditions. TOWIN Optics’ full range of IR-corrected CS-mount lenses – from 8MP high-resolution fixed focal to long-range varifocal models – are engineered to meet the diverse needs of global surveillance applications, with industry-standard compatibility, low-light optimization and durable design.

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Email: info@towin-elec.com

TOWIN Optics – Professional, All-Range, Easy, Fast – Your Trusted Optical Lens Supplier for Global Surveillance.