Why convert?
Analogue
With analogue media (film, vinyl records, magnetic tapes etc.),
the properties of the media are altered during the recording (or capturing)
process. The amount of the alteration to the properties of the media at any
moment is equal to the quantity of the information measured at that moment.
For example on a vinyl record, at the exact moment where a certain sound
was recorded, the groove will have a shape that is analogue (directly proportional)
to that sound.
On film, the amount of ink deposited on a specific
spot in a specific frame, is analogue (directly proportional) to the same position
of the real image that entered the lens of the camera when that frame was being
recorded.
In the case of reel tapes, videotapes and all other
magnetic media, the metal dust imbedded in the tape is magnetised by a specific
amount, directly proportional to the quantity of the information that it represents.
The deterioration
of analogue media.
Because the information is "captured"
in the physical
properties of the media, by altering the physical properties of the media, you alter the information. For example,
if you would give your precious vinyl record a light scratch (by accident of
course!), you will hear the scratch when you play the record because you have altered the physical
properties and therefor the original
information. Dust particles in the grooves of a vinyl record add annoying information that we do not want to hear.
With film, the ink changes colour over time and the film itself (the media)
becomes brittle. During normal, careful use, the film and projector will collect dust and this will in turn
cause scratches to the ink on the film. These physical alterations of the information
on the film WILL become visible.
Two magnetically charged particles of
opposite polarity has a 'cancellation'
effect on each other, over time. On magnetic media (reels
or cassettes), the layers of tape are wound physically close to each
other and this effect, known as "print-through", causes gradual degradation of the information.
Digital
Now let us look at the "digital"
way of saving information.
Using magnetic media as an example it will show
that it is NOT the "new" media types (like CD's and DVS’s) that provides
the big improvement, but rather the format
of the information
contained on the media,
namely digital.
DV (Digital Video) cameras, for example, still
use magnetic tape to store information - but only in digital format. Then why
would it be better?
You will remember that, during analogue recording
(or capturing), the properties of the medium are changed, in proportion to the
quantity of the information at that specific moment. During digital recording, the quantity of the information at
that specific moment is measured, and a number, proportional to the quantity, is assigned to that
moment.
This number is made up of only one's (1) and zero's (0). When no quantity (dead silence, for
example) is measured
at a specific moment,
the number assigned to that spesific moment in time, would typically be 16 zero's. If the maximum
quantity (a loud bang, for example) is measured, the number (containing 16 digits or BITS) assigned to that spesific
instant in time would all be 1's. And any quantity measured in between would result in a combination of one's and
zero’s, 16 of them. This number containing 16 digits is called a BYTE, or a 16 BIT word.
Now, when a "one"
is to be “recorded” onto the magnetic
tape, the full magnetisation force is applied to that specific fraction of tape.
When a zero is required to be recorded, the full magnetisation force is again applied, BUT
OF THE OPPOSITE POLARITY.
It can now be seen that the whole tape will contain magnetic
particles, magnetised
to their maximum, only different by polarity. For the digital playback device
to reproduce the ORIGINAL
quantity it only has to 'read' the magnetic polarity correct, to get the number right. Once the number is read off
the tape, the ORIGINAL information can be reconstructed.
It must now be clear that even if the particles
looses three-quarters of their magnetism over decades, as long as the polarity
information is still available, the ORIGINAL number (thus ORIGINAL SOUND or
PICTURE!) can be reconstructed.
If the information were in analogue
form, loosing three-quarters of the magnetism would mean loosing three-quarters
of the ORIGINAL INFORMATION! Never to be reconstructed to it's original form, EVER again!
Degradation of CD or DVD
During the “burning” of a CD or DVD, the laser burns spots onto a thin aluminium
layer sandwiched between two layers of transparent plastic. The device that
“reads” the spots on the disk, focuses only on the aluminium layer in the disk.
Every spot will be translated as a “one”. No spot translates into a "zero".
CD’s and DVD’s can and will scratch, and will also collect dust. But the “reading”
laser focuses on the aluminium layer INSIDE the disk and NOT on the surface of the disk, where the scratches and the dust are. If the scratch is not too serious and
the spots burnt during the recording process can still be distinguished through
the dust, the ORIGINAL information can be retrieved.
Your music will
sound EXACTLY like it did the first time. EVERY TIME! Even if you play the CD
or DVD a thousand times.
Conclusion
If your vinyl record had the same scratch and the same amount
of dust as the CD or DVD mentioned above, you will definitely hear it - EVERY
TIME!
And what about playing your vinyl record a thousand times? Its sound WILL change, even after playing it a hunderd times, because the needle alters the physical
properties (and therefor the information) slightly,
EVERY TIME you play it!
The bottom-line is: CONVERT
TO DIGITAL, BEFORE YOUR INFORMATION DETERIORATES ANY FURTHER !