Digital Recorders

DVRs perform the same function as VCRs but digitally encode bits to store images and store onto digital tape or hard drives. DVRs can delay or slow down the rate at which it records. i.e. real time (which is 50 fields per second or 25 frames per second in Europe), Timelapse DVRs (controlled frame rate less than 25 Fps) or Event (when an alarm is triggered). It is not just frame rate that decides how long the recorder will record for. Image compression, quality and colour/monochrome video to name a few parameters that affects the file size of the image thus how much hard drive capacity is used up. Thus for DVRs only an indication or rough estimate of the limits of playback time can be given but are still provided for a guideline.

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