[Frameworks] Analog and digital [was: Quo Vadis Celluloid?]

From: Fred Camper <f_at_fredcamper.com>
Date: Fri, 26 Aug 2011 09:23:12 -0500

Quoting tina wasserman <twasserman_at_verizon.net>:

> Just thought, another source for confusion in terms:
> in the definition below, would't 'digital' video also be an 'analog'
> process? If an analog process is ANY means to reproduce then why
> make the distinction between 'analog' and 'digital' video?

> --tina
> On Aug 25, 2011, at 9:05 PM, David Tetzlaff wrote:
>> An analog process is one that uses ANY means to reproduce or record
>> changes in phenomenon by creating an analog of those changes in
>> another medium.

The key to the difference is how data is translated and stored.

An "analog" process will store light, for example, as continuities,
such as a continuous set of shades of emulsion or a continuous set of
almost infinitely variable signals on tape. So for an image that is
moving from light to shadow, the signal on the tape would gradually
get "darker," or the emulsion would gradually get darker, not in
discrete steps but ideally continuously.

Digital translates everything into ones and zeros, and only that. The
entirety of a digital image consists only of discrete numbers. If the
translation is fine enough, meaning the bandwitdth broad enough, the
difference will be hard (or, in theory, impossible) to see: the number
signalling brightness will go from 30,000 to 29,999 and so on in slow
steps. But early music CDs were said to sound "colder" than vinyl
recordings which are analog; the grooves vary continuously signalling
the sound (and this is in a way similar to the apparent "flatness" of
digital imagery), possibly due to the fact that "not enough" 1s and 0s
were being used, so that some residue of the digital process remained,
though some of that has been "solved" by better engineering.

Also, in terms of handling the data, analog and digital data require
completely different tools. And in some ways digital data is far
easier to manipulate (hence the current state of "special effects").

Fred Camper

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Received on Fri Aug 26 2011 - 07:23:28 CDT