Wireless v.s. Wired v.s. DVR Spy Cameras

There are 3 major types of spy camera. Wired, Wireless and digital video recorder (DVR) spy cameras. These different types will usually dictate how the cameras can be used for surveillance. Here we explain each of these camera types, their benefits, their limitations, and some usage examples.

Wireless Spy Cameras

As the name suggests, wireless spy cameras use radio waves to transmit a video signal from the camera itself to a receiver. The receiver is usually connected to a recording system, particularly if the video footage is needed for evidence or use later on.

Common frequencies for publicly available wireless cameras are 1.2GHz and 2.4GHz. In the UK, 1.2GHz spy cameras (such as those purchased from the US or Asia) are not actually legal for use in the UK due to radio band limitations. However, 2.4GHz spy cameras are usually legal for use in the UK where you don’t need any kind of licence. This is because the 2.4GHz band is reserved for licence-free transmitting equipment.

Benefits

• Wireless cameras are easy to conceal, as there are no tell-tale wires to draw the attention of those under surveillance.
• They usually have a range of 30 to 100 metres, meaning that recording equipment can be concealed away from the camera.
• Wireless cameras can be battery or mains powered, giving you flexibility on how you conceal the camera.

Limitations

• Other wireless cameras and WiFi networks can sometimes interfere with the camera signal.
• Since the camera is transmitting, anyone with the appropriate receiver can also see the video footage. Therefore wireless cameras are not appropriate if you need privacy.

Typical Applications

• Bird and nature watching
• Child observation (also know as Nanny Cams)
• Cameras installed on helicopters and other radio-controlled vehicles
• Employee observation, particularly where there’s little space to install a camera.

Wired Spy Cameras

Wired cameras tend to be used for more permanent surveillance operations, and require the use of external recording and viewing equipment. Wired Spy Cameras usually have 3 or 4 wires that connect the camera to a power supply and recording equipment.

The wires correspond to:

• Power Supply – connected to positive terminal of battery or power adapter.
• Common Ground – connected to negative terminal of battery or power adapter, as well as ground of video and audio.
• Video Out – connected to the ‘positive’ or ‘signal’ part of a video cable. This is usually the inner wire of a video cable.
• Audio Out – connected to the ‘positive’ or ‘signal’ part of an audio cable. This is usually the inner wire of an audio cable. There isn’t always an audio connection to a spy camera, for example, CCTV cameras rarely have audio.

Benefits

• Your video footage cannot be intercepted by anyone in the way that wireless video signals can be. Therefore wired cameras offer a high degree of privacy.
• Wired cameras do not suffer from interference as wireless cameras do.
• Once set up, wired cameras are very reliable and are perfect for long-term projects.

Limitations

• You need separate recording and viewing equipment for wired cameras, which means wired cameras are typically not used for portable surveillance operations.
• Since wired cameras need power and video cables, you need to put some effort into hiding the wiring to make a wired camera completely covert.

Typical Applications

• Bird and nature watching
• CCTV systems – e.g. secure areas, door entry systems, storage areas
• Home security and remote observation (e.g. watching your home via the internet)
• Permanent and long-term surveillance

Digital Video Recorder (DVR) Spy Cameras

Digital Video Recorder (DVR) record video footage to some kind of digital storage. DVR spy cameras are the most modern development in spy camera technology. The video footage is digitised by the camera and then saved as a computer file onto flash memory or a memory card (e.g. SD and microSD cards).

To view the video file(s), you either connect the camera to a PC via a USB cable, or you remove the memory card and connect it to your PC using an adapter. Once connected to a PC, you can view, copy, edit and delete the video file as you would any other computer file. As technology improves, you’ll see new DVR cameras with higher resolutions and support for larger memory cards become available.

Benefits

• DVR cameras don’t use radio transmissions, which means video footage cannot be intercepted, unlike wireless cameras.
• DVR cameras don’t need any recording equipment, as they feature a digital recorder within the camera itself.
• Since DVR cameras digitise video footage as video is recorded, you can copy and share video files as you would any computer file. There’s no need for any other hardware to encode video into a digital form.
• Usually, DVR cameras are very small, so they can be worn on clothing or hidden within small bags.

Limitations

• DVR cameras tend to be only battery operated, making them less appropriate for longer term observations.
• Since DVR cameras use internal storage, that disk space will fill up eventually. Therefore you’ll need a PC to regularly move video footage off the storage medium.

Typical Applications

• Mobile surveillance – where you can hide a camera within clothing or bags.
• Ad-hoc surveillance – since cameras are often very portable, you can carry the camera around with you.