By: Arthur Cooper
Submitted: 2010-11-29 19:38:26 | Word Count: 664
A spy camera DVR or Digital Video Recorder usually differs from typical digital video security system DVRs because of the necessity for portability. Most spy camera models capture video at a lower size than standard which also requires lest DVR capacity.
Before we talk about a spy camera DVR, let’s discuss what a typical digital video security system is and how it works. Then we’ll discuss how this differs from a spy camera system and finally, what different types of spy camera DVRs are available.
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A typical, full sized digital video security system consists of three major components: 1. Digital video camera(s); 2. A DVR with a Digital Signal Processor or DSP; and, 3. One or more monitors. Each digital video camera captures video images by changing light energy into electrical energy that can be used to create digital video files. The DSP uses the data created by the digital video camera and actually creates the digital video file. The DSP stores the file on the DVR for later viewing on a monitor or the file can be viewed live on a monitor.
There are several optional features, deviations, and additions that can be made to the previous description, but that is a basic digital video system in a nutshell. There are two specifics we should mention about the digital video camera that may come into play with the use of a spy camera; how the images are captured and infrared imaging.
Digital video cameras work by focusing light from images onto a fairly small electronic sensor chip. There are two different sensor chips that can be used and although they differ slightly in how they transfer light energy into electrical energy they both produce the same product, data that can be used to create a video image. The sensors that are used are either a Charged Coupled Device or CCD and a Complimentary Metal Oxide Semiconductor or CMOS.
Both the CCD and the CMOS are also inherently sensitive to infrared radiation, specifically wavelengths or radiation called near infrared. This means with the proper lighting and filters a digital video camera can be designed to capture not only normal visible light images, but also infrared light images invisible to the human eye.
There are basically two methods of collecting security and surveillance video. The most popular method is overt recording. When capturing video overtly, there is no attempt to hide the video equipment. Covert recording is an attempt to capture video without the subject’s awareness. Covert recording systems are often called spy cameras or spy camera DVRs.
Most spy cameras achieve their status as “spy cameras” by disguising themselves within or as other objects. For example, Security Camera King has a vast selection of disguised or hidden (spy) cameras that are imbedded in or appear as exit signs, wall clocks, telephones, and many other items.
Some of these devices may also contain infrared Light Emitting Diodes or LEDs to illuminate areas in total darkness. As mentioned earlier, these infrared LEDs project a light that is invisible to the human eye but can be detected by an infrared digital video camera. As a result, these cameras can record video in total darkness.
Most of the spy cameras mentioned thus far can be connected to a basic standalone digital video security system that includes a standard DVR. The DVRs used in these systems are the like the hard disk drive in a computer. They contain a spinning plate and a magnetic head that moves about the plate recording the digital video files.
However, when we think of spy camera DVRs it is not the hard disk drive mentioned above. These spy cameras are often very small and compact or are imbedded in very small and compact objects. For example, Security Camera Kings product # HC-PEN Ink pen or HC-WATCH Wristwatch both record color video and audio. Their memory or spy camera DVR is built in solid state memory. Normally a special USB cable is used to transfer the data from this DVR to a personal computer.
Other types of spy camera DVRs may utilize a variety of small, non-mechanical solid state memory devices as their DVR medium of choice. For example, some spy camera DVRs consist of thumb drives, Flash memory cards like SD cards, Mini Compact Flash cards and the like.
Modern technological improvements have created physically smaller yet larger in capacity spy camera DVRs. Check out our full line of spy cameras in our on-line catalogue.
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