防犯カメラ

A security camera, or surveillance camera, is a closed-circuit television (CCTV) camera used to monitor areas for any suspicious activity or other phenomena of interest. Some key points about security cameras:

• Monitor areas of interest for safety, security, and surveillance purposes. Things like unauthorized access, vandalism, theft, etc. 
• Contain lenses and image sensors that convert optical images into digital video signals for recording and monitoring. 
• Connected to a video or network video recorder that records the footage. The footage can then be reviewed if any incidents occur.
• Common types of security cameras include dome cameras, bullet cameras, box cameras, PTZ cameras, covert cameras, etc. Depending on the needs, they differ in features like weather resistance, night vision, zoom, etc.

The key features of security cameras include weather resistance, night vision, motion detection, remote access, two-way audio, etc.

• They help deter criminal behavior through visible surveillance. The cameras can also be used to identify offenders by recording visual evidence.
• The footage from security cameras can also be used for analysis, e.g., counting people entering/leaving a location, tracking vehicle movements, etc. 
• Newer IP security cameras can stream and record video over a network connection. This allows for centralized monitoring of cameras installed in multiple locations.
• Security camera systems require proper installation, configuration, and monitoring to operate effectively and meet security objectives.

Here is a summary of how typical security cameras work:

1. Capturing images: Security cameras contain image sensors like CMOS or CCD chips that detect the light coming through the camera lens and convert it into electronic video signals. These sensors allow the cameras to capture images and footage of the areas they monitor continuously. 
2. Processing the video: The electronic video signals from the image sensors are then processed and encoded into a standard video format like H.264 or MJPEG that can be stored, transmitted, and monitored effectively. This includes compression, encryption, image adjustments and more. Some cameras also apply image analysis techniques at this stage to detect motion or objects of interest.
3. Storage and transmission: The processed video signals can be stored locally on a memory card or network video recorder or transmitted over a network, depending on the camera type. Most cameras offer both storage and transmission options. The footage is saved and streamed continuously in a loop. 
4. Night vision: Many security cameras have infrared (IR) illuminators and image sensors that can capture clear footage even in total darkness. The IR lights emit infrared light that reflects off subjects and is detected by the cameras, allowing them to see in very low light or at night. 
5. Motion detection: Many security cameras can analyze video footage for motion detection. They detect and filter changes between frames to sense movement in the monitored area. When motion is detected above a set sensitivity threshold, the camera can trigger alerts, switch to a high-sensitivity mode, and enable recording or other configured actions.
6. Alerts and notifications: Security cameras provide alerts and notifications to update monitoring personnel about important events dynamically. This can include motion detection alerts, tampering alerts, storage full alerts, and push notifications to mobile devices or email alerts. Audible alarms are also possible with some cameras. 
7. Monitoring and reviewing footage: The recorded footage from security cameras can be monitored live or reviewed as recordings to analyze for any incidents, security breaches or other events of interest. Footage can be reviewed instantly or searched to find relevant clips. Live monitoring also allows immediate response to any emergencies detected. 
8. Enabling remote access: Network-connected security cameras allow authorized personnel to access live feeds, recordings, and alerts and manage the cameras remotely over a network from any location. This enables centralized monitoring of multiple camera locations and instant response even for geographically dispersed systems.
   

There are a variety of security cameras available in the market. To give you a rich information, we have summarized 5 types of sercuity cameras.With the detailed information introduced, we believe you will have a better understanding of different types of security cameras.

Indoor vs. Outdoor Security Cameras:
Indoor cameras: Used for indoor surveillance. They have standard housings and lenses. Easier to install but limited weather resistance.

Outdoor cameras: Used for outdoor surveillance. They have weather-sealed housings and lenses to prevent damage from weather. More difficult to install but have better weather resistance. 

Wired vs. Wireless Security Cameras:
Wired cameras: Connected to cables that transmit the video signal. Easier to set up but limited flexibility in positioning and installation. Vulnerable to cable cuts.
Wireless cameras: Transmit video signals wirelessly using wireless networks. More flexible installation but requires an additional effort to set up the wireless network. Limited range and bandwidth compared to wired networks.

Analog vs. Digital Security Cameras:
Analog cameras: Capture and transmit analog video signals. Lower resolution, more prone to interference, and harder to integrate into IP networks. Slowly being replaced by digital cameras.
Digital cameras: Capture and transmit digital video signals. Provide higher resolution, more reliability, easier IP integration and compression. Most modern cameras are digital.

IP (Internet Protocol) Cameras:
IP cameras: Capture and transmit digital video over IP networks. Provide remote access, interoperability and integration into IP networks. Allow centralized monitoring over large installations. More secure and flexible than analog/digital cameras. Most widely used technology today.

PTZ Cameras
PTZ cameras: Have pan-tilt-zoom lenses that can physically move and rotate to change the field of view. Allow remote controlling and automation of the camera's field of view. Useful for covering large areas with a few cameras. However, moving parts reduce reliability and vandal resistance.
Fixed-lens cameras: Have fixed lenses with a static field of view. Simpler, more reliable, and vandal-resistant, but the field of view cannot be changed remotely.

Here are some key benefits of using security cameras:

1. Deter Crime: Visible security cameras can deter criminals and vandals by making them feel watched. Cameras act as a visible deterrent against unlawful behavior. 
2. Record Evidence: Security camera footage can serve as valuable evidence for investigations and help identify suspects. Footage of crimes, threats, or accidents can be reviewed to analyze events and provide evidence to prosecutors. 
3. Monitor Activities: Cameras continuously record activities in the areas under their coverage. You can monitor for suspicious behavior, ensure safety standards are met, or log customer traffic. Live viewing or recorded footage can be reviewed at any time.
4. Remote Access: IP security cameras provide remote access, which allows monitoring of your facilities from anywhere. You can view live streams and recorded footage online on your mobile devices or in control rooms. This enables responding quickly to incidents and managing multiple locations centrally.
5. Insurance Discounts: Security camera installations are often eligible for discounts from insurance providers like property or liability insurance. Cameras can reduce risks of damage, threats, accidents, or lawsuits, which prompts insurers to lower premiums for businesses and homeowners with security camera systems. 
   
6. Improve Security: Overall, security cameras strengthen the safety and security of people, property, and business operations. They provide surveillance coverage, detect threats, monitor access, record evidence and deter unlawful behavior. As valuable assets and people are protected, peace of mind is an additional benefit.
   
   

When choosing security cameras, here are some important features to consider:

1. Video Quality: Get cameras that provide clear, high-definition video footage for good image quality even when enlarged or printed.1080p (Full HD) or 4K resolution is good for most applications. Check megapixel count for daylight quality and low-light performance. 
2. Night Vision: For outdoor cameras, night vision allows monitoring in complete darkness. Infrared LEDs illuminate subjects at night while invisible to the human eye. A range of at least 30 feet is recommended. 
3. Motion Detection: Cameras with built-in motion detection can detect moving subjects in the field of view. They start recording and sending alerts when motion is detected, allowing quick footage review from those cameras. Motion zones and schedules also give more control over alerts. 
4. Storage Options: Decide between local storage, network storage, or both:
   • Local Storage: SD/SDHC cards allow quick, easy storage but limited capacity and duration. Good for smaller installations. 
   • Network Storage: NVRs (network video recorders) provide centralized storage over a network, allowing remote access and management. Much larger storage capacities and long retention periods. 
   • Hybrid: Some cameras have built-in storage plus network connectivity, giving you both local and remote storage options, which both offer benefits with flexibility.
5. Two-way Audio: Allows audio communication between the monitoring personnel and people within the camera's field of view using a microphone and speaker built into the camera. It can warn intruders, communicate with visitors/staff or get additional information during an incident. Only available in certain IP camera models. 

Some other useful features include wireless connectivity, IP rating, remote access, PTZ control, alarm inputs/outputs, smart features like facial recognition, awkward posture detection, people counting, etc., depending on your needs.

Here are some tips for security camera installation and maintenance:

1. Placement Tips
   • Mount cameras at eye level for the best view. Don't place them too high or too low.
   • Cover entry/exit points and blind spots. Ensure all areas of interest are within at least one camera's view. 
   • Consider lighting conditions. Place cameras in a way that avoids glare on lenses from indoor/outdoor lighting. Night vision cameras require some ambient light for color vision.
   • Minimize obstructions. Ensure no permanent obstructions like poles, beams, or walls block the camera's view. Allow room on all sides of the field of view. 
   • Consider wiring and cabling. Install cameras in a way that minimizes the need for long cabling runs, which can reduce image quality and cause signal loss. 
2. Weatherproofing
   • For outdoor cameras, install weather-sealed housings with an IP rating matching environmental exposure levels (like IP66/IP67 for outdoor use). This prevents water/dust damage to internal components.
   • Use weatherproof cables and connectors outside for all connections to outdoor cameras and power supplies/network equipment. Weatherproof assemblies should provide an airtight seal.
   • Apply weatherproof sealants/lubricants to threads and mating surfaces of components to prevent water entry through tiny gaps. Reapply periodically to maintain protection.
3. Power Source
   • Most cameras require AC power, while some support PoE (Power over Ethernet) or DC power. Choose compatible power sources.
   • Ensure adequate power supply capacity based on the number of cameras, cable length, and power draw of each camera.
   • Weatherproof transformers/power supplies are needed for outdoor cameras. Standard units can only be mounted indoors.
4. Maintenance And Upkeep
   • Check camera view and field of view regularly for any obstructions. Clear or reposition as needed.
   • Ensure all visual elements, including lenses, dome covers, and housings, are clean and clear of dust/grime. This prevents decreased visibility or water/dirt entry into the camera. 
   • Weathercoat any exposed wires/connectors leading to outdoor cameras to maintain weather protection, especially for wires rubbing on surfaces. 
   • Test night vision cameras in infrared mode periodically to ensure enough IR LED power for complete nighttime coverage. Infrared LEDs can reduce over time. 
   • Update the firmware to the latest versions whenever the manufacturer releases security updates for components like cameras, NVRs, etc. This ensures protection against vulnerabilities.
   • Test system storage capacity regularly to delete old recordings and ensure new recordings overwrite old footage if storage space is limited. 
   • Consider professional maintenance contracts for basic servicing and upkeep, especially for large or critical systems.

While we enjoy the benefits and convenience brought by security cameras, there are also some factors we cannoy ignore. Based on our experiecence, we have summarized below bullet points for your to have another side of views.

1. Privacy Concerns: Security cameras monitor public areas and record/store video footage, which can be a privacy concern for some. Although cameras cannot usually identify individuals directly, the footage may still capture sensitive details or activities. Proper signage indicating camera presence helps address this. 
2. False Sense Of Security: Security cameras provide visibility and recording but do not physically prevent unwanted activity like theft, vandalism, or violent incidents. They can give a false sense of full security as criminals may still attempt harm despite camera monitoring. Other security measures are still required. 
3. Cost: The total cost of a security camera system is not just the cost you buy a camera. Besides what you paid to the camera, you also need to include expenses such as:
   • Initial costs: Cameras, lenses, housings, cables, NVRs/network equipment, wiring, installation, etc. This can be significant, especially for large systems. 
   • Ongoing costs: Storage media, network bandwidth fees, insurance, licensing/permits fees, maintenance contracts, system upgrades, etc. These recurring costs can add up over time.
   • Hidden costs: Additional equipment may be needed for wireless connectivity, night vision, weather resistance, etc. Upgrades may also become necessary as technology improves.
   • Labor costs: Professional system installation and configuration and occasional maintenance and repair or upgrade work can increase the total cost. Some systems, especially larger integrated systems, can easily cost several thousands of dollars. The ongoing commitment to related costs should also be considered before purchasing.

While improved security and safety benefits are well worth the costs for many, higher upfront or long-term costs can be prohibitive for smaller businesses, homeowners, or those on a budget. There are also cheaper DIY options, though professional installation is often recommended for the best results.

1. Do I need a professional to install my security camera?
   Not necessarily, but professional installation can ensure proper placement and wiring for optimal performance.
2. Can security cameras be hacked?
   While any technology can potentially be hacked, taking proper security measures such as using strong passwords and regularly updating firmware can mitigate the risk.
3. Can security cameras record audio?
   Some security cameras offer two-way audio communication, but recording audio may require additional legal considerations depending on location.
4. How much storage space do I need for my security camera footage?
   This will depend on factors such as the length and quality of your footage, but it's generally recommended to have at least a few days' worths of storage capacity.
5. Can I access my security camera footage remotely?
   Many security cameras offer access to live footage remotely through a smartphone or computer, but check your specific camera's capabilities before purchasing.