"WHY should we buy the gold disc (original) and NOT the purple disc (DVD-R)?"
Malaysians of a certain age will have heard this phrase many times before, especially when playing DVDs that used to be sold at pasar malam and shops with dimly lit entrances.
But is there any truth to this claim, which is set to a clip of an action-packed car chase sequence from a movie about an international man of mystery from Old Blighty?
Verdict:
FALSE
In short, no. A sweeping statement like this ignores too many factors, such as the source of the programme on the disc or even how well the disc itself is made.
To provide a more precise answer, we need to briefly explain how optical disc technology – which includes CD, DVD and Blu-ray – works.
Disc readers or players, use a laser to "read" what is on the reflective side of the disc.
In a standard non-recordable CD like those we play our music and movies from (or used to), data is stored in a series of "pits" (a groove or indentation) and "lands" (a flat area) which are physically "stamped" (or etched) on a plastic disc. These pits and lands make up the "ones (1)" and "Zeroes (0)" of the digital binary code.
The surface with the pits and lands is then coated with a reflective metal layer, which is usually made from aluminium or even gold, which allows the laser to read the data.
This ultra-thin sheet of metal is then coated with another layer, what we perceive as the label printed on the top surface, which protects the metal layer and the stamped-in data from damage.
What a recordable disc (CD-R, DVD-R) does, is to simulate these pits and lands, which are "burned" using a laser beam on a layer of dye.
The colour of this dye varies from (you guessed it!) purple, green, blue and even gold!
Another layer of reflective metal is coated over the dye, so to the disc player or reader, the "burned" areas "look" just like the pits and lands in regular manufactured discs.
It should be noted that only the dye-based discs are "recordable" as data on discs with actual metal layers are physically stamped in via a manufacturing process.
According to hi-fi and music enthusiast Joseph Loh, what the purveyors of these DVDs of dubious legality are presumably trying to say is that their discs are proper "stamped" discs and not "burned" DVD-Rs.
"A normal assumption would be that discs with metallic layers last longer as the data is 'stamped' into the surface compared to simulated pits and lands 'burned' on a layer of dye.
"However, this ignores the quality of materials used to make the disc and how stringent its manufacturing process is," he said.
He added that if cheap materials are used to create a stamped disc, it will logically not last as long as a recordable disc made with top-shelf materials.
"Discs made by sweaty workers slogging away in a hidden room are never going to match the quality of discs manufactured in a pristine, modern facility where every step of the manufacturing process is tightly controlled.
"All these are factors that will affect both the readability of the disc and its shelf life," said Loh.
As for playback quality, a modern-day adage perfectly describes it: "Rubbish in, rubbish out".
If the same source data is used, what is stored on either manufactured or recordable discs will be identical, with no difference in playback quality whatsoever.
However, if the source of the movie is as dubious as the disc's provenance itself – for example, if obtained using a video camera trained on a cinema screen – then it will simply not look or sound as good as one officially released by production studios.
And no, it will not look or sound better, even if it was on a gold disc.
References:
1. https://electronics.howstuffworks.com/question287.htm
2. http://www.osta.org/technology/cdqa15.htm
3. https://www.edocpublish.com/resources-2/history-of-taiyo-yuden-cd-r/
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