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Optical Fingerprint Modules vs Capacitive Fingerprint Modules — What's the Core Difference?

Date:2025-11-28

Optical Fingerprint Module vs Capacitive Fingerprint Module: What's the Core Difference?

  • Optical fingerprint modules — like CAMABIO's CAMABIO Optical Fingerprint Module — use light reflection / imaging: when you place a finger on the glass (or transparent) surface, internal light (LED or other) illuminates the fingertip; a photosensor (similar to a camera) captures a 2D image of the fingerprint ridges and valleys 

  • Capacitive fingerprint modules — such as CAMABIO's CAMABIO Capacitive Fingerprint Module — use electrical capacitance: an array of microscopic capacitors beneath the surface measures the difference in electrical charge caused by ridges (closer to sensor) vs valleys (farther) when a finger touches the surface. That pattern is converted into a digital fingerprint “image”. 


Thus the core difference: optical sensors capture an optical image; capacitive sensors capture an electrical/capacitive map of the fingerprint.

Key Comparisons: Accuracy, Durable, Hardware & Cost
Factor Optical Fingerprint Module
Capacitive Fingerprint Module
Recognition Accuracy & Precision Usually with a larger scan area with more fingerprint features,it will have lower FRR and FAR
Usually with a small scan area with less fingerprint features,it will have higher FRR and FAR
Hardware Durable
Often use a glass (or transparent) platen —
sturdy and resistant to external shocks
More fragile: as a semiconductor-based chip
under a protective cover,require careful surface protection
ESD Capability
not sensitive to electrostatic discharge (ESD) more sensitive to ESD
Form Factor / Size Larger — the optical path, lens/prism/CCD typically requires more space. That can make optical modules bulky Compact: semiconductor chip + capacitor array allows for a thin, small form factor — easier to embed in compact or portable devices (smartphones, small embedded systems, locks, IoT, etc.).

Hardware Structure & Integration Considerations

Optical modules incorporate light source + optics (prism or lens) + photosensor (CCD/CMOS), plus protective glass/platen. That typically results in a thicker, bulkier hardware assembly. Such modules suit environments where size is not the main constraint — e.g. access control panels, time-attendance terminals, desktop biometric readers.

Capacitive modules are built around semiconductor chips + capacitor array + protective cover; often very flat, thin, and compact. That enables embedding into slim or space-constrained devices — such as smartphones, tablets, slim smart locks, or IoT devices.

CAMABIO offer both kinds: for example, optical modules such as “CAMA-SM25 OEM Optical Fingerprint Module” or “CAMA-SM50 Embedded Optical Fingerprint Module,” and capacitive ones like “CAMA-AFM360V3M FBI PIV Certified Fingerprint Scanners,” or “CAMA-AFM288 Capacitive Fingerprint Scanner Module

Suitable Scenarios: When to Use Which

Use Optical Modules (e.g. CAMABIO optical series) when:

  • You are building access control systems, door locks, attendance systems, kiosks — i.e. moderate-security, many-user environments where cost per unit must remain low.

  • Device size is not tightly constrained (desktop, wall-mounted, embedded but not ultra-slim).

  • You value cost-effectiveness, hardware robustness, and ease of maintenance over maximum security.

  • The environment is relatively clean and dry (indoor, controlled lighting) — so optical imaging quality stays good.


Use Capacitive Modules (e.g. CAMABIO capacitive series) when:

  • You design compact or portable devices — Handheld, tablets, small smart locks, IoT devices — where space is limited.

  • Security matters (personal data, payments, device unlocking, sensitive operations).

  • Users expect reliable, fast, accurate fingerprint authentication under a variety of finger conditions (dry, clean, slightly dirty).

  • You want resistance against fake fingerprints and a more “secure” biometric system.