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[email protected] genericaudioperson@hotmail.com is offline
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Default digital photography vs. digital audio

Are there any meaningful parallels that can be drawn between digital
photography and digital audio?

For example, if you take a digital photo with a high-megapixel count,
this means you can enlarge the picture more before you start to see
imperfections.

So if you record a 24-bit signal just under clipping, does that mean
you can get away with wider level adjustments in the DAW mixing
environment before noticing signal degradation?

I've formed some analogies:
linearity of audio recorder= lens quality
frequency range of recorder=color accuracy
bit depth of recorder= pixel count

Any truth to that?

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Meindert Sprang Meindert Sprang is offline
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Default digital photography vs. digital audio

wrote in message
oups.com...
Are there any meaningful parallels that can be drawn between digital
photography and digital audio?


Yes, one is 1D, the other 2D.

For example, if you take a digital photo with a high-megapixel count,
this means you can enlarge the picture more before you start to see
imperfections.

So if you record a 24-bit signal just under clipping, does that mean
you can get away with wider level adjustments in the DAW mixing
environment before noticing signal degradation?


I've formed some analogies:
linearity of audio recorder= lens quality
frequency range of recorder=color accuracy
bit depth of recorder= pixel count


Purely from a mathematical 1 dimensional audio to 2 dimensional photography
comparison, it would be more like this:

linearity of audio converter = linearity of video converter
frequency range of audio recorder = combined resolution of image sensor and
lense
bit depth of recorder = bit depth of image sensor
sample frequency of recorder = number of pixels on one image line.

Meindert


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Arny Krueger Arny Krueger is offline
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Default digital photography vs. digital audio

wrote in message
oups.com

Are there any meaningful parallels that can be drawn
between digital photography and digital audio?


Other than questionable metaphors, probably not.

For example, if you take a digital photo with a
high-megapixel count, this means you can enlarge the
picture more before you start to see imperfections.


I've never seen a photograph of something with substance that could be
confused with a view of the origional object, after a close inspection.

So if you record a 24-bit signal just under clipping,
does that mean you can get away with wider level
adjustments in the DAW mixing environment before noticing
signal degradation?


Now that is true. If you attenuate a FS 16 bit signal 64 dB, there is only
about 32 dB left. This is usually highly audible degradation. If you
attenuate a FS 24 bit signal 64 dB, there is still about 80 dB left, and
that is rarely if ever an audible amount of degradation.

Lesson to learn - use 24 bits or more for mixing and EFX.



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Paul Stamler Paul Stamler is offline
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Default digital photography vs. digital audio

wrote in message
oups.com...
Are there any meaningful parallels that can be drawn between digital
photography and digital audio?

For example, if you take a digital photo with a high-megapixel count,
this means you can enlarge the picture more before you start to see
imperfections.

So if you record a 24-bit signal just under clipping, does that mean
you can get away with wider level adjustments in the DAW mixing
environment before noticing signal degradation?


In theory yes; see Arny's analogy in the other thread about a signal with a
72dB dynamic range. In a 24-bit system you could theoretically drop its
level 72dB, then bring it back up, and you'd only add a few dB of noise.

That's not analogous to a high pixel count in photography, though; if you
wanted to draw an analogy for that, it'd probably be a high audio sampling
rate rather than bit depth. But you're still comparing two very different
things.

I've formed some analogies:
linearity of audio recorder= lens quality
frequency range of recorder=color accuracy
bit depth of recorder= pixel count

Any truth to that?


Nope.

Peace,
Paul


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[email protected] genericaudioperson@hotmail.com is offline
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Default digital photography vs. digital audio

wow, you can move -72db and then +72db with only slight signal
degradation? that's good news. i thought if you moved much more than
6db in either direction you would be causing distress on the audio
file. maybe 24 bit recording with 32bit float mixing gives you more
room to move without penalty than i thought.


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Scott Dorsey Scott Dorsey is offline
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Default digital photography vs. digital audio

wrote:
wow, you can move -72db and then +72db with only slight signal
degradation? that's good news. i thought if you moved much more than
6db in either direction you would be causing distress on the audio
file.


6 dB is about one bit.

If you take a 16 bit value, and you store it as a 24 bit integer (scaled
up by four bits), you can attenuate it by four bits (24 dB) or amplify
it by four bits (24 dB) without clipping, truncating, or changing its
value in any way.

The whole point is that the intermediate representation should be wider
than the inputs and outputs, so you have this freedom.

maybe 24 bit recording with 32bit float mixing gives you more
room to move without penalty than i thought.


Oh, go to 32 bit floats and you have enormous room to move.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Default digital photography vs. digital audio

On Apr 26, 9:47 am, wrote:

Are there any meaningful parallels that can be drawn between digital
photography and digital audio?


The only parallel that I've found to be a constant between digital
photography and digital audio is amount of money you shell out for
more gear. Both are bottomless pits, lol.

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Deputy Dumbya Dawg[_3_] Deputy Dumbya Dawg[_3_] is offline
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Default digital photography vs. digital audio


wrote in message
oups.com...
Are there any meaningful parallels that can be drawn between
digital
photography and digital audio?



This is meaningful to me.

* One can compare two photographs side by side.
* One can only listen to single performance piece of audio at
a time and compare what they are now hearing to what they
remember hearing earlier, and audio memory is very short.

peace
dawg




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Boris Lau Boris Lau is offline
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Default digital photography vs. digital audio

Arny Krueger wrote:
I've never seen a photograph of something with substance that could be
confused with a view of the origional object, after a close inspection.


Have you heard an audio recording of something with substance (e.g.
singer, instrument) that could be confused with listening of the
original object after a close inspection? I haven't...

Boris





--
http://www.borislau.de - computer science, music, photos
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Scott Dorsey Scott Dorsey is offline
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Default digital photography vs. digital audio

Boris Lau wrote:
Arny Krueger wrote:
I've never seen a photograph of something with substance that could be
confused with a view of the origional object, after a close inspection.


Have you heard an audio recording of something with substance (e.g.
singer, instrument) that could be confused with listening of the
original object after a close inspection? I haven't...


I have, once or twice in my life. My goal is to make that experience
more common.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Paul Stamler Paul Stamler is offline
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Default digital photography vs. digital audio

"Boris Lau" wrote in message
...
Arny Krueger wrote:
I've never seen a photograph of something with substance that could be
confused with a view of the origional object, after a close inspection.


Have you heard an audio recording of something with substance (e.g.
singer, instrument) that could be confused with listening of the
original object after a close inspection? I haven't...


I have, four times, but *not* on close inspection. On two occasions, I was
standing just around the corner from my remote monitoring setup when I heard
Phil Cooper (a musician I was recording) ask me a question. Both I opened my
mouth to answer before realizing that the voice was recorded rather than
real, and that Phil was standing in front of me with his lips not moving.

On one occasion, I was in an audio showroom when somebody banged something
directly behind my right shoulder. I jumped and spun around; of course,
there was nothing there. They had a not-particularly great JBL surround
system in the room.

Finally, when I worked as service manager at the Speaker and Stereo Store, I
was coming from the back room toward the front when I stopped and said, "Why
does Wylie have a drum kit set up in the store?" When I came into the room,
I realized it wasn't a drum kit, but an SACD recording of one, played back
on not-particularly-great AR speakers.

Four occasions, each of them times when my backbrain was fooled. All in
casual mode, not analytical mode.

For the record (so to speak), the first two instances were on analog tape
(15 ips, half track, NAB EQ, no NR); the next was probably a Laserdisc; the
last, as mentioned, was an SACD. Monitor speakers: Rogers LS3/5a's, JBL
surround system, c. 2000-vintage AR speakers, respectively.

Peace,
Paul


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Default digital photography vs. digital audio

we could talk about how when you play a certain aphex twin track in a
spectrograph, you can see his face



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Default digital photography vs. digital audio

On Fri, 27 Apr 2007 14:31:51 -0400, Scott Dorsey wrote:

Boris Lau wrote:

Have you heard an audio recording of something with substance (e.g.
singer, instrument) that could be confused with listening of the
original object after a close inspection? I haven't...


I have, once or twice in my life. My goal is to make that experience
more common.


Bet a nickel it WASN'T on Memorex.

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Boris Lau Boris Lau is offline
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Default digital photography vs. digital audio

Boris Lau wrote:
Pictures = 2D over time.

nope: Pictures = 2D over space. That's what I meant so say ;-)
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Arny Krueger Arny Krueger is offline
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Default digital photography vs. digital audio

"Boris Lau" wrote in message

Arny Krueger wrote:
I've never seen a photograph of something with substance
that could be confused with a view of the origional
object, after a close inspection.


Have you heard an audio recording of something with
substance (e.g. singer, instrument) that could be
confused with listening of the original object after a
close inspection? I haven't...


I have been fooled, and I've fooled others. The basic trick i've used is to
make a good close-miced recording of a small group performing in a room, and
then play the recording back in the same room from pretty good speakers in
the same general vicinity as the origional performance.


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Boris Lau Boris Lau is offline
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Default digital photography vs. digital audio

Arny Krueger wrote:
Have you heard an audio recording of something with
substance (e.g. singer, instrument) that could be
confused with listening of the original object after a
close inspection? I haven't...


I have been fooled, and I've fooled others. The basic trick i've used is to
make a good close-miced recording of a small group performing in a room, and
then play the recording back in the same room from pretty good speakers in
the same general vicinity as the origional performance.


Well, yeah. But I'm still suspicious about that "close inspection part" ;-)

--
http://www.borislau.de - computer science, music, photos


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Laurence Payne Laurence Payne is offline
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Default digital photography vs. digital audio

On Sat, 28 Apr 2007 04:22:08 +0200, Boris Lau
wrote:

I have been fooled, and I've fooled others. The basic trick i've used is to
make a good close-miced recording of a small group performing in a room, and
then play the recording back in the same room from pretty good speakers in
the same general vicinity as the origional performance.


Well, yeah. But I'm still suspicious about that "close inspection part" ;-)


If you "closely inspect" a live performance, you'll find all kinds of
fault with it. Hopefully, the music and the performance take over
your attention so that all but gross technical imperfections are
masked.
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Scott Dorsey Scott Dorsey is offline
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Default digital photography vs. digital audio

John Lamp wrote:
wrote:
Are there any meaningful parallels that can be drawn between digital
photography and digital audio?


The slide into obsolescence is equally precipitous!


It is a little weird, isn't it? Definitely bad news from a business
perspective.

In high school, I saved up from a summer job to buy a Crown Graphic.
I still have it. Today, I could probably sell it for about what I
paid for it (though admittedly the dollar is worth less). You can
see some photos taken with it in the latest Recording magazine; I
still use it regularly.

A fellow at work bought a high end digital camera three years ago
and now cannot get even get media for it.

This is even _worse_ than the audio world. The analogue audio world
is inconsistent too: the ATR-100 machines have held their value, while
you can pick up an Ampex 440 (which is really a nice sounding machine)
for next to nothing. And the higher end digital stuff holds its value
for at least a couple years.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Default digital photography vs. digital audio

(Scott Dorsey) writes:

I have, once or twice in my life. My goal is to make that experience
more common.


Could you share with us what they where?
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Arny Krueger Arny Krueger is offline
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Default digital photography vs. digital audio

"Boris Lau" wrote in message


Arny Krueger wrote:


Have you heard an audio recording of something with
substance (e.g. singer, instrument) that could be
confused with listening of the original object after a
close inspection? I haven't...


I have been fooled, and I've fooled others. The basic
trick i've used is to make a good close-miced recording
of a small group performing in a room, and then play the
recording back in the same room from pretty good
speakers in the same general vicinity as the origional
performance.


Well, yeah. But I'm still suspicious about that "close
inspection part" ;-)


Point well taken. I doubt that there would have been any problem discerning
the audible difference in a close comparison. But as others have pointed
out, real world listening tends to be monadic, which is an inherently
insensitive type of evaluation.





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Default digital photography vs. digital audio

"Laurence Payne" lpayne1NOSPAM@dslDOTpipexDOTcom wrote in
message
On Sat, 28 Apr 2007 04:22:08 +0200, Boris Lau
wrote:

I have been fooled, and I've fooled others. The basic
trick i've used is to make a good close-miced recording
of a small group performing in a room, and then play
the recording back in the same room from pretty good
speakers in the same general vicinity as the origional
performance.


Well, yeah. But I'm still suspicious about that "close
inspection part" ;-)


If you "closely inspect" a live performance, you'll find
all kinds of fault with it. Hopefully, the music and the
performance take over your attention so that all but
gross technical imperfections are masked.


Good point. Beginning recordists run afoul of this all the time. They make a
recording that is often pretty fair, but wonder why the live performance
sounded so good, and the recording sounds so bad.

This also applies to the performance itself. People who listen for pleasure
often miss a lot of mistakes during the live performance. I don't have a
problem with this. I sort of miss the days when I could listen to music
without my "critical listening module" becoming engaged.

Real world example from the past week. I was sitting in the sound booth with
a semi-pro vocalist at my elbow during a performance. After the show she was
oohing and ahhing over another vocalist's performance. I said something
like, well it was OK, but she made the following fairly serious mistakes -
bing, bing, bing, and bing. When I say serious, the one I remember most
clearly is that she started singing a verse during a bridge, about 4
measures early. She recovered pretty well, but... Furthermore, I've
recorded her performing that song at least 4 times, and her voice is getting
so harsh that I have been premptively low pass filtering it at progressively
lower frequencies for everybody's benefit. It just came out.

Part of being an experienced live performance recordist is hearing as many
fixable problems as possible during the setup and (hopefully) the rehearsal
(s), and then fixing as many of them as possible before the final take.
Hopefully you have a director or producer on hand to work the musical issues
out with the talent.


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Default digital photography vs. digital audio

For the record (so to speak), the first two instances were on analog tape
(15 ips, half track, NAB EQ, no NR); the next was probably a Laserdisc; the
last, as mentioned, was an SACD. Monitor speakers: Rogers LS3/5a's, JBL
surround system, c. 2000-vintage AR speakers, respectively.

Peace,
Paul


AR had a touring classical string quartet back in the '60s. They
would play on a local stage with AR speakers on each side of the
group. As the performance went on, the drapes would close. A minute
or so later the drapes would open to reveal the musicians comfortably
at rest as the music continued. The changeover was pretty near
seamless.

That demo sold a lot of speakers.

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John L Rice John L Rice is offline
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Default digital photography vs. digital audio

"Meindert Sprang" wrote in message
l.nl...
wrote in message
oups.com...
Are there any meaningful parallels that can be drawn between digital
photography and digital audio?


Yes, one is 1D, the other 2D.


Wouldn't it depend on the audio source, how it was recorded and the
playback system?
mono ~ single point to 1D
stereo ~ 1D to 2D
quad/surround ~ 2D to 3D
octophonic ~ 3D
etc, etc

Photography is at least 2D and if you consider holography etc it can also be
3D.

John L Rice


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Take Vos Take Vos is offline
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Default digital photography vs. digital audio

Hi,

I've formed some analogies:
linearity of audio recorder= lens quality
frequency range of recorder=color accuracy
bit depth of recorder= pixel count

Any truth to that?

Sort off, and, not really.
There are actually a few more dimensions and frequencies domains
involved than one would expect with video.

Lets start with a single pixel of a grey scale camera.
- audio sample rate = video framerate
The value of a video pixel is read say around 24 frames per
second.
- audio bit depth = video bit depth
The value of a video pixel is read using a 10, 12, 14 or 16
bit A/D converter
- audio gain = pixel gain
an amplifier is used to increase the signal strength of a
pixel before entering the A/D converter, there is also a bias
component this is to seed a pixel with some more signal so that the
linearity improves.
- audio noise = pixel noise
A pixel includes noise from the amplifiers, quantization noise
from the A/D converter, and electrical noise picked up by the sensor.
- diagraph (how do you write that) size = pixel well size.
A larger pixel can receive more photons and with it reduce the
signal noise.
- high notes aliasing = high object movement aliasing.
It is not really called aliasing in the video world, but the
effect is nevertheless the same, objects that move fast are not seen
by a pixel, only object that move slower than the frame rate will be
seen.

As you see every effect you would have for audio from a single
microhpone, would correspond to a single grey scale picture of a video
camera.

Now imagine you have lots of microphones put in a grid, maybe you want
to make a wall of sound, the output of which would be to a speaker
array, think surround sound taken to the extreme. This is very similar
to a video sensor.

- each microphone is different = each pixel is different
You have to know the bias and sensitivity for each pixel and
compensate for it, otherwise it would show as static noise.

Now, if you have a lot of microphones you could have a single A/D
converter for each, but that may not be cost effective, for video at
least it is not. Instead each pixel has a sample and hold circuity,
and each pixel is quickly read one by one by a single A/D converter
through the same amplifier. Larger image sensors divide the image in
two or four regions each with a amplifier and A/D converter.

Then there is the lens, you could use an array of directional
microphones pointing them to a slightly different direction. you can
theoretically do the same with an image sensor, increase the well
depth of each pixel and point each well to a slightly different
direction. The problem is the amount of photons that will be exactly
parallel to a well is very low, so you need a lot of light, just like
a long microphone will receive a lot less sound. Instead we use a lens
to capture a lot of photons and point the photons to the correct pixel
well.

In this array you also have aliasing, object that are seen by one
pixel and not the other, the keep high resolution you want to use a
optical filter in front of the sensor, that scatters the photons
randomly in multiple pixel wells.

Then there is color, you take a grey scale camera, and put a colored
filter in front of each pixel, so one pixel is only used for red, and
other for green and yet an other for blue. It is like putting
different sound absorbing materials in front of each microphone in the
array, so that each responds to a low, mid or high frequency range
(this is not a perfect analogy).

In the video world they are running in to the same issues as the audio
world has with low bit depths. Current cameras have quite a low
contrast range and storing each pixel value into 8 bits does not help.
It is like using a compressor/limiter on all the pixels to fit in such
a low range of values. Luckily this is changing and we are now going
into an era that will be using HDR (High dynamic range) imaging, the
edit applications are using floating point, cameras are outputting
high bit depth and found algorithms to increase the psychological
dynamic range of a display (which are still only 8 bit).

Ok, this is already a long post and I will shut up now.

Cheers,
Take Vos
analogy boy


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Barry Barry is offline
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Default digital photography vs. digital audio

On Apr 26, 12:47 pm, wrote:
Are there any meaningful parallels that can be drawn between digital
photography and digital audio?

For example, if you take a digital photo with a high-megapixel count,
this means you can enlarge the picture more before you start to see
imperfections.

So if you record a 24-bit signal just under clipping, does that mean
you can get away with wider level adjustments in the DAW mixing
environment before noticing signal degradation?

I've formed some analogies:
linearity of audio recorder= lens quality
frequency range of recorder=color accuracy
bit depth of recorder= pixel count

Any truth to that?


24 bit is denser than say 16

far as a camera.. see it the same as sound.. just depends on how dense
the pixels are.






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Scott Dorsey Scott Dorsey is offline
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Default digital photography vs. digital audio

Paul Repacholi wrote:
(Scott Dorsey) writes:

I have, once or twice in my life. My goal is to make that experience
more common.


Could you share with us what they where?


Well, one of them was the first time I heard the LS 3/5a. The vocal sounded
like it was right there in front of me, and it was the first time I ever
heard a playback that sounded like the real thing. Then the band came in
and it was clear that it was a tape.... but with just the vocal, it was
nothing short of eerie.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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