on 8/30/02 8:28 AM, Austin Franklin at darkroom@ix.netcom.com wrote:
> Roy,
>
>> All the stuff about number of levels and resolution are artifacts of the
>> digital process and not part of the DyR concept which existed way before
>> the word digital was even coined.
>
> I don't know if that is true or not, as I don't know who "invented" the
> characterization, or when it was "invented"...I am trying to find out. I
> take it, for you to make this as a statement of fact, you know the actual
> history of dynamic range? Who "invented" it? What's your earliest
> reference of "dynamic range"?
Hi Austin,
There are some words that are "invented" but by and large most English words
come from way, way back. So for the word "dynamic" all the dictionaries
I've looked at reference Old French and Greek. dynamo- means power or
powerful. The word "range" has an awful lot of meanings including where the
cows hang out and homes used to be :) But I suspect we can agree on the
mathematics notion of a bounded set of values. I.e. there's a max and a min
and all the values in between are in the range.
So, when were the words put together? Since humans make "sound" more
readily than they make "light", the words were used as applied to sound
first. For anyone who plays a musical instrument, the word "dynamics" has
always been used to indicate how loud you are playing. A piece of music
with lots of "dynamics" is one that has quiet sections and loud sections.
Playing with "dynamics" means playing softly and loudly. An instrument has a
range of dynamics based on how soft or loud it can be played. The piano was
invented around 1600 specifically to have a keyboard instrument with a
greater range of dynamics than the harpsichord. The name in fact was
originally "pianoforte" which literally means soft/loud. The point is that
the term "dynamic range" was coined and used in common language for a long
time before there was a technical definition and formula. So the term was
in common usage and the concept in place way before someone tried to
calculate a value for it --- not a technical formula looking for a name and
coining "dynamic range".
The best reference for "dynamic range" as applied to "light" is Ansel Adams
book set "The Negative" in the chapter "The Zone System". Here's my edition
quote: "The full range from black to white is represented by Zones 0 to X.
Within this lies the "dynamic range" representing the first useful values
above Zone 0 and below Zone X, or Zone I to IX. The range of zones which
convey definite qualities of texture and the recognition of substance is the
"textural range" from Zones II to VIII."
There's also a diagram illustrating the above paragraph. I don't know when
he first used these terms but he was teaching the Zone System in the 1940's.
All of the above is consistent with the standard usage of the word "range"
(i.e. values from a max to a min). Also "dynamics" meaning "power" is also
consistent. A loudest sound is a max power and a quietest sound is a min
power. Similarly a brightest light is a max power and a dimmest light is a
min power.
> ...but you're just so damn prolific, and
> repeating the same thing...and it gets tiring and frustrating...with nothing
> (seemingly) new added. This post was short and easy, and quite to the
> point...which I'm happy to respond to. If you can keep the posts short, I'd
> be a lot happier.
>
> Regards,
>
> Austin
Short is good, I hope that's short enough.
Roy
PS. At the risk of lengthening the post, the following is just references
to the web. I don't think there's anything to respond to, since I didn't
write them.
Roy
----------------------
In my first post to max-noise that you didn't see, I cited lots of
references to the use of the term dynamic range as applied to audio.
If you just humor me and think "range of power" and read through the
references, I don't see how you can miss the consistency of concept.
I spent a short time searching for "audio dynamic range" with google. This
is every definition of dynamic range that I found, not at all a select list:
Dynamic range describes the ratio of the softest sound to the loudest sound
in a musical instrument or piece of electronic equipment. This ratio is
measured in decibels (abbreviated as dB) units.
----
Dynamic range is the ratio of maximum undistorted signal (full-scale or
onset of clipping) to residual noise (noise floor). Dynamic range in
generally measured in decibels (dB).
-----
dynamic range -- the difference in loudness between the loudest peak and the
"noise floor" of your equipment.
-----
The dynamic range of an audio signal is the difference between the quietest
discernible part of the signal and the loudest undistorted part of the
signal. It is normally expressed in decibels (dB).
-----
This is a particularly nice one:
A short definition of dynamic range is probably in order at this point.
Dynamic Range (DR) as used in this paper is best described as the ratio of
the largest signal to the smallest signal in volts peak to peak, measured at
a given single frequency. The largest signal would be determined by applying
a signal to the unit and increasing the input to the unit until the unit's
specified total harmonic distortion (THD+N) is surpassed. The smallest
signal would be determined by applying a signal of the same frequency and
reducing the input until the output of the unit can no longer be
distinguished from the noise floor. This methodology works for either analog
or digital systems and by measuring either the input swing required or the
output swing given specifies input or output dynamic range (IDR or ODR)
respectively.
-----
Dynamic Range - 1) The level difference (in dB) between the loudest peak and
the softest level of a tune recording etc. 2) The level difference between
the level of clipping and the noise level in an audio device or channel.
Here's why we use the adjective "Dynamic":
Dynamics - 1) The amount of fluctuation in level of an audio signal. 2) In
music, the playing of instruments loudly or softly at different times.
------
dynamic range: The range between the loudest and the softest sounds that are
in a piece of music or that can be reproduced by a piece of audio equipment
without distortion. This is a ratio expressed in decibels (dB).
Roy Harrington
roy@harrington.com
Black & White Photography Gallery
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