Analog Camera Parameter Encyclopedia: Comprehensive Guide for Industrial Selection and Application

Overview of Analog Camera

An analog camera, also known as a CCTV analog camera, is a video capture device that transmits analog video signals over coaxial cables (typically using BNC connectors) to a digital video recorder (DVR) or monitor. Unlike IP cameras, analog cameras do not compress or digitize video internally; they output raw composite video (CVBS) in standards such as PAL (625 lines, 50 fields/sec) or NTSC (525 lines, 60 fields/sec). Analog cameras remain widely used in industrial environments, legacy security systems, and cost-sensitive installations due to their simplicity, low latency, and compatibility with existing coaxial infrastructure.

Working Principle of Analog Camera

The analog camera operates by converting light through a CCD (Charge-Coupled Device) or CMOS sensor into an electrical signal. The sensor captures the image, and a built-in DSP (Digital Signal Processor) performs basic analog processing such as white balance, gain control, and synchronization. The processed signal is then modulated into a composite video waveform according to the chosen TV standard (PAL/NTSC). The video signal is transmitted unidirectionally over 75-ohm coaxial cable, with typical voltage levels of 1 Vpp (peak-to-peak). Sync pulses are embedded in the signal to maintain frame and line alignment. Power is usually supplied separately via a DC power adapter (12V DC, commonly 0.5A to 2A) or through the same coaxial cable in a “power over coax” configuration (e.g., 24V AC or DC).

Definition of Analog Camera

In the context of industrial video surveillance, an analog camera is defined as a fixed or vari-focal imaging device that outputs a continuous analog waveform representing a real-time video stream. The definition excludes any digital encoding (e.g., H.264, H.265) at the camera level. The video quality is primarily determined by the sensor resolution and the TV line resolution (TVL) rating, typically ranging from 420 TVL to 700 TVL for standard definition, and up to 1000 TVL for ultra-high resolution analog cameras (often labeled as “HD analog” or “960H”). Note that even high-resolution analog cameras still use analog transmission; they are not to be confused with HD-TVI, AHD, or CVI technologies which are hybrid analog/digital transmission methods.

Application Scenarios of Analog Camera

Analog cameras are predominantly deployed in the following industrial and commercial settings:

• Factory & Warehouse Surveillance: Monitoring production lines, assembly areas, and inventory storage zones where network reliability is secondary to cost efficiency.
• Construction Sites: Temporary installations for perimeter security and equipment monitoring; analog cameras are preferred due to easy cabling and no network configuration required.
• Old Building Retrofits: Upgrading from VCR to DVR systems without replacing existing coaxial wiring – analog cameras integrate seamlessly with coaxial infrastructure.
• Transport & Parking: License plate capture and gate monitoring in parking garages, toll plazas, and railway stations where low latency is critical.
• Critical Infrastructure: Power plants, water treatment facilities, and remote pump stations where analog cameras offer inherent immunity to IP network vulnerabilities (no IP address, no cyberattack surface).

Classification of Analog Camera

Analog cameras are classified by several characteristics. The table below summarizes the main categories:

Performance Indicators of Analog Camera

Key performance indicators (KPIs) for analog cameras are measured using industry-standard test charts (e.g., ISO 12233 for resolution, and lab lux meters for sensitivity). Below are the critical metrics:

Key Parameters of Analog Camera

When specifying an analog camera for industrial use, the following parameters require careful attention:

• Resolution (TVL): For general monitoring, 520–650 TVL is adequate. For forensic detail (e.g., reading labels on moving conveyor belts), 700 TVL or higher is recommended.
• Sensor Type and Size: 1/3-inch or 1/4-inch CCD (higher sensitivity and lower noise) vs. CMOS (lower cost, higher integration). Pixel count: 768×576 (PAL) for standard 440k pixel area; 976×582 for 960H (570k pixel).
• Signal Output Level: Standard 1 Vpp into 75 ohm. Deviation beyond ±10% may cause sync loss on DVR.
• Lens Mount: CS-mount (most common) or S-mount for board cameras. Flange back distance: 12.5 mm for CS mount, 17.52 mm for C mount.
• Power Supply: 12V DC ±10%, typical current 250–500 mA. Some outdoor models accept 24V AC/DC or PoC (Power over Coax).
• IR Cut Filter: Mechanical IR cut filter (ICR) for day/night switching is standard in outdoor models. Response time < 1 second.
• Video Frame Rate: 50 fps (PAL) interlaced, 60 fps (NTSC). This is fixed by the TV standard and does not change with resolution.

Industry Standards for Analog Camera

Analog cameras must comply with several international and regional standards:

• Electromagnetic Compatibility (EMC): FCC Part 15 (USA), CE (Europe) – radiated and conducted emissions limits.
• Safety: UL 60950-1 (IT equipment), IEC 62368-1 for power supply safety.
• Environmental Protection: IP rating per IEC 60529 (IP67 for outdoor), IK rating per IEC 62262 (IK10 for vandal-proof).
• Video Signal Standard: PAL (CCIR 624), NTSC (EIA RS-170A). For 960H cameras, the horizontal blanking interval is shortened to fit 960 active pixels in the same 52 μs line period, per the EIA-770.2 standard.
• Coaxial Cable Specification: RG-59/U or RG-6/U, impedance 75 ± 3 ohms, capacitance 52–67 pF/m, attenuation < 0.25 dB/m at 10 MHz.

Precision Selection Essentials and Matching Principles for Analog Camera

To ensure reliable performance in industrial environments, follow these selection criteria:

1. Resolution vs. Field of View: For a 10 m wide coverage area, a 700 TVL analog camera with a 2.8 mm lens (horizontal FoV ~100°) yields approximately 140 pixels per foot, suitable for detection. For identification (120+ pixels per foot), use a 6 mm lens (FoV ~50°) or increase resolution to 1000 TVL.
2. Low-Light Performance: Choose CCD-based cameras with 0.01 lux sensitivity for dimly lit manufacturing floors. Use CMOS cameras only if the minimum light exceeds 0.5 lux.
3. Sync Matching with DVR: For multi-camera installations, select line-lock sync cameras if the DVR supports it; otherwise use internal sync. Avoid mixing internal and line-lock cameras on the same DVR unless the DVR has a built-in genlock adjustment.
4. Cable Length Budget: For reliable 1 Vpp signal at 75 ohm, maximum recommended cable length: 200 m for RG-59, 300 m for RG-6 at 5 MHz bandwidth. Beyond 300 m, use a video balun or inline amplifier.
5. Power Cable Gauge: For 12V DC, voltage drop should not exceed 10%. Use 18 AWG cable for runs up to 50 m, 16 AWG for 100 m. For PoC systems, limit current to 500 mA per coaxial line.

Procurement Pitfalls to Avoid for Analog Camera

Common mistakes when purchasing analog cameras for industrial use:

• Overrating TVL: Some vendors claim 1000 TVL using a low-quality sensor. Always verify with a test chart; 1000 TVL should resolve 50 line pairs per millimeter on a 1/3” sensor.
• Ignoring Lens Quality: A cheap plastic lens with F1.8 may produce blurry edges even with a high-resolution sensor. Insist on all-glass IR-corrected lenses with F1.2 or better.
• Power Over Coax Compatibility: Not all DVRs support PoC. Check voltage and pinout (commonly positive on video center conductor, negative on shield). Reverse connection may damage the camera.
• IR Illuminator Mismatch: Cameras with built-in IR LEDs have a specified range (e.g., 20 m). If the coverage distance is longer, use an external IR array.
• Temperature Rating: For outdoor factory use, ensure operating temperature range -40°C to +60°C. Cameras rated only 0–40°C will fail in winter or near hot machinery.

Usage and Maintenance Guide for Analog Camera

Proper maintenance extends analog camera lifespan in harsh industrial settings:

• Lens Cleaning: Use a microfiber cloth with isopropyl alcohol (70%). Do not use ammonia-based glass cleaners that can damage the lens coating.
• Cable Inspection: Check BNC connectors monthly for corrosion or loose crimps. Replace any cable with measured attenuation exceeding 20% above spec.
• Firmware/Config Backup: Most analog cameras have no internal memory for settings (except PTZ). For DVR-side settings (e.g., BLC, AGC), document per-camera values in a maintenance log.
• Environmental Protection: For outdoor cameras, clean IR window glass every 6 months. Check housing gaskets for cracks; apply silicone grease to O-rings annually.
• Voltage Check: Measure camera input voltage at the connector. If voltage is below 10.8V DC, check the power supply and cable drop.

Common Misconceptions about Analog Camera

Clarifying frequent misunderstandings in the field:

• Myth: Analog cameras cannot provide IP video. Reality: Analog cameras can be connected to an encoder (DVR encoder card) to produce IP streams. The analog camera itself is not IP-capable, but the system can still integrate with a network.
• Myth: Higher TVL always means better image quality. Reality: TVL measures only horizontal resolution. Noise, latency, and color reproduction are equally important. A 600 TVL camera with high S/N (50 dB) outperforms a 700 TVL camera with 40 dB S/N in low light.
• Myth: Analog cameras are obsolete. Reality: Analog cameras still represent over 40% of the industrial CCTV market (2024 data) due to cost, simplicity, and cyber security (no IP footprint). They are ideal for applications where network reliability cannot be guaranteed.
• Myth: All coaxial cables are the same. Reality: RG-59 and RG-6 have different impedance, capacitance, and attenuation. Using RG-59 for a 250 m run will cause signal loss; RG-6 or a signal booster is required.
• Myth: Analog cameras can be daisy-chained. Reality: Analog cameras must be home-run to the DVR. Splitting signals with a T-connector severely degrades impedance matching and causes ghosting.