difference between digital and analog recording
For all practical purposes, analog recording is what we generally think of when using our vcr or audio cassette recorders. Analog recording consists of heads writing or reading signals directly onto a medium (like a tape) with a magnetic encoding. Digital, on the other hand – also reads/writes data but encodes the signals into a numeric string of digits. There are a couple different ways in which we generally use digital video/ audio recording:
1. Directly onto a computer’s magnetic hard drive through a variety of compression formats- such as in PC (Windows) based systems and embedded OS / Linux based systems such as our DVR-N4, or;
2. Onto a magnetic tape cassette, as used with mini decks (Sony’s GVD-200 and GVD-800) and new digital camcorders. The major tape formats found in new digital camcorders are Sony’s ‘Digital 8’ or the more common ‘Mini-DV’ . No analog equipment will record or playback digital media, but some digital units (GVD-200/ 800) do have the ability to playback analog format(s). 8mm, Hi-8 and VHS-C are the standard tape formats for today’s analog camcorders.
*Mini decks and camcorders are used in limited covert and mobile uses for short-term recording, but are generally not considered part of the security / surveillance industry. Please click here to see a terrific miniature digital video recorder made for portable use.
Digital technology has become much more stable and reliable in the last 2 or 3 years and is quickly replacing analog video recording to the point of impending extinction. If you didn’t rush into anything- and are still clinging to your worn out old timelapse VCR- there’s no better time than NOW to upgrade it. Prices have finally become AFFORDABLE for a product which is actually both reliable AND user friendly.
One KEY advantage to DIGITAL is its higher resolution ability. Depending on features of individual unit, you may be able to achieve 480+ horizontal lines recording with digital recorders vs. 300 lines color (350 bw) with the highest quality analog units (such as our high band/ high density Sanyo models). Most analog recorders permit only about 280 lines for black and white and 240 lines for color.
Analog recording can still be argued to be little reliable due to the fact that a videotape (mechanical) drive system is not likely to “crash” like a computer hard drive or operating system might, risking some or all data to irretrievable loss. And many security professionals are using redundancy systems with a digital recorder as the primary system- backed up by a high density/ high resolution analog VCR.