D200 vs D300 at ISO 1600

Chris Malcolm wrote:
Floyd L. Davidson wrote:
Chris Malcolm wrote:

While jpeg compression is a lossy form of compression, in the sense
that you can't undo it to return to an exact replica of the original,
something is lost in the compression, non-linear encodings aren't
necessarily lossy compressions.

The added quantization distortion in the higher levels
is due to an error that cannot be subtracted after the
fact. The original signal cannot be recovered, therefore
whatever "compression" exists is by definition lossy.

You may be thinking of trying to recover the original analog
signal. Strictly speaking it's impossible to do that perfectly. It's
only possible to do it within defined limits of accuracy. Once you've
done it to the extent that your senses or your instruments can't tell
the difference it's as perfect as it needs to be.

That is nonsense.

There is a much stricter and simpler definition of lossy compression,
however, which applies in the case of jpeg compression, and that is
when we're talking about compressing a digital representation. In that
case exact recovery has a precise and very easily measured meaning. A
method of compression is lossy if you can't recover an exact replica
of the original file. Jpeg was designed as an inherently lossy method
of compression. If you translate another kind of image file to jpeg
and back again you inevitably lose something.

And that of course is the same definition I used above...

But there are lossless methods of file compression with which recovery
of an exact replica from the compressed file is possible. ZIP is a
well known example. In the field of digital image compression the new
JPEG 2000 and JPEG XR standards both include lossless compression
options.

And gamma-corrected encoding is NOT one of them.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

On Thu, 10 Apr 2008 19:02:48 -0800, (Floyd L.
Davidson) wrote:

John O'Flaherty wrote:
On 10 Apr 2008 23:02:14 GMT, Chris Malcolm
wrote:
that I was talking about linear encoding:

"To me, 'dynamic range' means the ratio of the full scale to the
smallest significant change. If you are using linear encoding as
opposed to companding or something, that would translate directly to a
number of bits. If 12 bits are used, the dynamic range is 2^12:1, at
most."

In any case, lossy compression wasn't the subject of my comment. I
referred only to the idea that "dynamic range", as the term is usually
understood, is independent of number of bits.

While jpeg compression is a lossy form of compression, in the sense
that you can't undo it to return to an exact replica of the original,
something is lost in the compression, non-linear encodings aren't
necessarily lossy compressions.

If it is not a lossy compression, then someone kindly cite an example
where it compresses but the exact original signal can be recovered.

It is inherently a lossy compession.

As to nonlinear encodings, suppose you take the logarithm of a
digitized signal, to a precision much greater than the original
representation, and transmit mantissa changes continually, but
transmit the exponent only when it changes. That would be a nonlinear
compression, but would allow perfect recovery of the original signal.
If you refer to the compression of a digitized image, lossless
compression is very common. A simple example is: don't transmit or
store values that repeat n times, just use the value once along with
the number of repetitions (run length encoding).
Any digitized signal, which is necessarily already quantized, is a
set of numbers and can probably be compressed without loss by
algorithms that find patterns in the numbers. Once compressed by an
efficient routine, the signal can't be compressed further with the
same or another algorithm.
If you are starting with an unquantized signal that represents a real
number, you can't compress its magnitude without some loss (=
quantization), but if the losses are way less than the noise level,
nothing meaningful has been lost.
--
John

John O'Flaherty wrote:
On Thu, 10 Apr 2008 19:02:48 -0800, (Floyd L.
Davidson) wrote:
If it is not a lossy compression, then someone kindly cite an example
where it compresses but the exact original signal can be recovered.

It is inherently a lossy compession.

As to nonlinear encodings, suppose you take the logarithm of a
digitized signal, to a precision much greater than the original
representation, and transmit mantissa changes continually, but
transmit the exponent only when it changes. That would be a nonlinear
compression, but would allow perfect recovery of the original signal.

First, that is not what we are referring to by
"non-linear encoding" compared to "linear encoding".
That is a totally different data rather than a different
encoding.

Regardless, it will not allow perfect recovery of the
original signal, for the same reason that one cannot
perfectly recover the original analog signal after it is
digitized. Quantization error, whether of the signal
itself or of the changes in the signal, will distort the
output compared to the input.

It is only totally recoverable if you happen to have
infinite bandwidth, SNR, or time. See Claude Shannon's
"A Mathematical Theory of Communication", 1948.

If you refer to the compression of a digitized image, lossless
compression is very common.

Not due to non-linear encoding schemes it isn't!

We are *NOT* talking about whether data can be
compressed without loss. It can. But we are talking
about gamma-corrected encoding which compresses the data
to reduce bandwith by lowering the number of bits per
sample.

Your examples do not match the request.

A simple example is: don't transmit or
store values that repeat n times, just use the value once along with
the number of repetitions (run length encoding).
Any digitized signal, which is necessarily already quantized, is a
set of numbers and can probably be compressed without loss by

You should have said "and might possibly be compressed"... :-)

algorithms that find patterns in the numbers. Once compressed by an
efficient routine, the signal can't be compressed further with the
same or another algorithm.

If you are starting with an unquantized signal that represents a real
number, you can't compress its magnitude without some loss (=
quantization), but if the losses are way less than the noise level,
nothing meaningful has been lost.

That is also a relatively useless accomplishment! In
fact practical quantization *always* involves data loss.
Again, as I've pointed out befo that *is*
quantization error.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

"Rita Berkowitz" vehemently accused in
m:

Steve wrote:

Don't be fooled into thinking that by shooting RAW your WB
settings doesn't have any effects on the image. An improperly
set WB will result in a significantly higher noise floor for
your RAW images. This is most evident on the blue channel. WB
settings drive other key camera settings that will affect
image quality.

Ok, so please explain to me how the camera WB setting effect
the raw image other than by just recording what the WB setting
was in the EXIF data and by using it for the embedded JPEGs?

There are many more articles, but here's a simple one.

"This article was great because it really dispels the myth that
RAW can fix everything; the camera literally captures
differently depending on its white balance setting."

http://www.ppmag.com/web-exclusives/...balance-the-se
cret-weapo-1.html

Maybe I just don't understand but everything I've read and
witnessed leads me to believe that the WB setting doesn't do
anything at all to the image data in the raw file.

You, like many others, erroneously assume RAW data is just that,
100% unprocessed data from the sensor, it is not. WB is
calculated into setting many different camera parameters, even
simple ones such as how the camera exposes an image. True, you
can always change this is post, but at a cost. Set you WB so you
can intentionally blow your blue channel and come back and tell
what you find after you correct it in post. You get more leeway
with RAW than using JPG, but you are still not getting a free
lunch shooting RAW. That is why it is so important to get it
right in-camera.





Rita


Is it too late to jump in on this one?

I read the article in "ppmag" and I have a question: is the
author suggesting that because changing the color/WB sliders while
manipulating a RAW file is the same as (or at least comparable to)
varying the WB settings that were set when the RAW was taken? Is
she suggesting that post-shot processing is directly comparable to
shot-taking settings? Am I misunderstanding this? I mean, she is
comparing 2 different conversions/manipulations of 1 RAW file, not
comparing multiple RAWs and RAW settings, right?
May I propose a (hopefully) rigorous way to examine this: take
a series of shots of the same object/scene in the exact same
lighting conditions, but in every "basic" WB setting. In fact, we
could go further and do the same thing for every Kelvin increment
setting, I think.
If the RAW histograms are all the same, then WB does not affect
RAW exposure; if they vary, then WB does affect exposure. We could
even estimate how much they affect exposure.
So, is WB metadata that is recorded at exposure, but does not
directly affect; or is it a "mask" that is recorded *and* applied
at exposure?
I don't have the answer, but this clearly is an important
issue, and I certainly would like to know, so I can set my camera
properly, depending on what I hope to accomplish at any given
shoot.
Or do all y'all want to continue with the sniping, which I must
say is terribly clever and entertaining. (Not really.)

Willa
--
http://www.pbase.com/willarojo

“I came into this world, not chiefly to make this a good place to
live in, but to live in it, be it good or bad.”
Thoreau, Civil Disobedience

“We are in great haste to construct a magnetic telegraph line from
Maine to Texas; but Maine and Texas, it may be, have nothing
important to communicate.”
Thoreau, Walden

Rita Berkowitz wrote:
Cynicor wrote:

The term "spread spectrum" is not used when talking about digital
imaging; it's a radio/telecom term. Are you referring to the "Active
D-Lighting" feature, which does affect the saved RAW image?

No, I'm not referring to "Active D-Lighting". The term/technology is
also being used in digital imaging as well to describe this new
groundbreaking technology. Nikon even used a TXCO in the prototype
D3, but scrapped the idea because of the steep current drain on the
battery.

Sources?

Absolutely!

http://imaging.nikon.com/proto/imaging/hash/test/pdf/index.htm

You lose! Thread's over.

Cynicor wrote:
Rita Berkowitz wrote:
Cynicor wrote:

The term "spread spectrum" is not used when talking about digital
imaging; it's a radio/telecom term. Are you referring to the
"Active D-Lighting" feature, which does affect the saved RAW
image?

No, I'm not referring to "Active D-Lighting". The term/technology
is also being used in digital imaging as well to describe this new
groundbreaking technology. Nikon even used a TXCO in the prototype
D3, but scrapped the idea because of the steep current drain on the
battery.

Sources?

Absolutely!

http://imaging.nikon.com/proto/imaging/hash/test/pdf/index.htm

You lose! Thread's over.

Surprise, surprise!

David

David J Taylor wrote:
Cynicor wrote:
Rita Berkowitz wrote:
Cynicor wrote:

The term "spread spectrum" is not used when talking about digital
imaging; it's a radio/telecom term. Are you referring to the
"Active D-Lighting" feature, which does affect the saved RAW
image?
No, I'm not referring to "Active D-Lighting". The term/technology
is also being used in digital imaging as well to describe this new
groundbreaking technology. Nikon even used a TXCO in the prototype
D3, but scrapped the idea because of the steep current drain on the
battery.
Sources?
Absolutely!

http://imaging.nikon.com/proto/imaging/hash/test/pdf/index.htm
You lose! Thread's over.

Surprise, surprise!

Dude, I said the thread was over!

On Apr 13, 12:35 am, Willarojo wrote:
"Rita Berkowitz" vehemently accused innews:YsmdneCCFrE4gGTanZ2dnUVZ_qvinZ2d@supernews. com:



Steve wrote:

Don't be fooled into thinking that by shooting RAW your WB
settings doesn't have any effects on the image. An improperly
set WB will result in a significantly higher noise floor for
your RAW images. This is most evident on the blue channel. WB
settings drive other key camera settings that will affect
image quality.

Ok, so please explain to me how the camera WB setting effect
the raw image other than by just recording what the WB setting
was in the EXIF data and by using it for the embedded JPEGs?

There are many more articles, but here's a simple one.

"This article was great because it really dispels the myth that
RAW can fix everything; the camera literally captures
differently depending on its white balance setting."

http://www.ppmag.com/web-exclusives/...balance-the-se
cret-weapo-1.html

Maybe I just don't understand but everything I've read and
witnessed leads me to believe that the WB setting doesn't do
anything at all to the image data in the raw file.

You, like many others, erroneously assume RAW data is just that,
100% unprocessed data from the sensor, it is not. WB is
calculated into setting many different camera parameters, even
simple ones such as how the camera exposes an image. True, you
can always change this is post, but at a cost. Set you WB so you
can intentionally blow your blue channel and come back and tell
what you find after you correct it in post. You get more leeway
with RAW than using JPG, but you are still not getting a free
lunch shooting RAW. That is why it is so important to get it
right in-camera.

Rita

Is it too late to jump in on this one?

I read the article in "ppmag" and I have a question: is the
author suggesting that because changing the color/WB sliders while
manipulating a RAW file is the same as (or at least comparable to)
varying the WB settings that were set when the RAW was taken? Is
she suggesting that post-shot processing is directly comparable to
shot-taking settings? Am I misunderstanding this? I mean, she is
comparing 2 different conversions/manipulations of 1 RAW file, not
comparing multiple RAWs and RAW settings, right?
May I propose a (hopefully) rigorous way to examine this: take
a series of shots of the same object/scene in the exact same
lighting conditions, but in every "basic" WB setting. In fact, we
could go further and do the same thing for every Kelvin increment
setting, I think.
If the RAW histograms are all the same, then WB does not affect
RAW exposure; if they vary, then WB does affect exposure. We could
even estimate how much they affect exposure.
So, is WB metadata that is recorded at exposure, but does not
directly affect; or is it a "mask" that is recorded *and* applied
at exposure?
I don't have the answer, but this clearly is an important
issue, and I certainly would like to know, so I can set my camera
properly, depending on what I hope to accomplish at any given
shoot.
Or do all y'all want to continue with the sniping, which I must
say is terribly clever and entertaining. (Not really.)

Willa
--http://www.pbase.com/willarojo

"I came into this world, not chiefly to make this a good place to
live in, but to live in it, be it good or bad."
Thoreau, Civil Disobedience

"We are in great haste to construct a magnetic telegraph line from
Maine to Texas; but Maine and Texas, it may be, have nothing
important to communicate."
Thoreau, Walden

The test that you have suggested has been conducted and reported on
two or three times throughout this thread and WB has made absolutely
no difference to exposure while shooting RAW, as the histograms have
remained identical.

PixelPix wrote:
On Apr 13, 12:35 am, Willarojo wrote:
"Rita Berkowitz" vehemently accused innews:YsmdneCCFrE4gGTanZ2dnUVZ_qvinZ2d@supernews. com:



Steve wrote:
Don't be fooled into thinking that by shooting RAW your WB
settings doesn't have any effects on the image. An improperly
set WB will result in a significantly higher noise floor for
your RAW images. This is most evident on the blue channel. WB
settings drive other key camera settings that will affect
image quality.
Ok, so please explain to me how the camera WB setting effect
the raw image other than by just recording what the WB setting
was in the EXIF data and by using it for the embedded JPEGs?
There are many more articles, but here's a simple one.
"This article was great because it really dispels the myth that
RAW can fix everything; the camera literally captures
differently depending on its white balance setting."
http://www.ppmag.com/web-exclusives/...balance-the-se
cret-weapo-1.html
Maybe I just don't understand but everything I've read and
witnessed leads me to believe that the WB setting doesn't do
anything at all to the image data in the raw file.
You, like many others, erroneously assume RAW data is just that,
100% unprocessed data from the sensor, it is not. WB is
calculated into setting many different camera parameters, even
simple ones such as how the camera exposes an image. True, you
can always change this is post, but at a cost. Set you WB so you
can intentionally blow your blue channel and come back and tell
what you find after you correct it in post. You get more leeway
with RAW than using JPG, but you are still not getting a free
lunch shooting RAW. That is why it is so important to get it
right in-camera.
Rita
Is it too late to jump in on this one?

I read the article in "ppmag" and I have a question: is the
author suggesting that because changing the color/WB sliders while
manipulating a RAW file is the same as (or at least comparable to)
varying the WB settings that were set when the RAW was taken? Is
she suggesting that post-shot processing is directly comparable to
shot-taking settings? Am I misunderstanding this? I mean, she is
comparing 2 different conversions/manipulations of 1 RAW file, not
comparing multiple RAWs and RAW settings, right?
May I propose a (hopefully) rigorous way to examine this: take
a series of shots of the same object/scene in the exact same
lighting conditions, but in every "basic" WB setting. In fact, we
could go further and do the same thing for every Kelvin increment
setting, I think.
If the RAW histograms are all the same, then WB does not affect
RAW exposure; if they vary, then WB does affect exposure. We could
even estimate how much they affect exposure.
So, is WB metadata that is recorded at exposure, but does not
directly affect; or is it a "mask" that is recorded *and* applied
at exposure?
I don't have the answer, but this clearly is an important
issue, and I certainly would like to know, so I can set my camera
properly, depending on what I hope to accomplish at any given
shoot.
Or do all y'all want to continue with the sniping, which I must
say is terribly clever and entertaining. (Not really.)

Willa
--http://www.pbase.com/willarojo

"I came into this world, not chiefly to make this a good place to
live in, but to live in it, be it good or bad."
Thoreau, Civil Disobedience

"We are in great haste to construct a magnetic telegraph line from
Maine to Texas; but Maine and Texas, it may be, have nothing
important to communicate."
Thoreau, Walden

The test that you have suggested has been conducted and reported on
two or three times throughout this thread and WB has made absolutely
no difference to exposure while shooting RAW, as the histograms have
remained identical.

I have put this reply on the end of this post, 'cause my news server has
hiccuped and lost the earlier posts.

The *only * situation that blows a channel - any or all channels - is
overexposure at the time of taking the shot. If the photon wells in the
chip max out, then the channel is blown; if they are not maxed out then
the camera will not blow a channel. In-camera settings do not have any
effect on RAW files - at least with Canon cameras. You can blow a
channel in Photoshop with levels or curves, however, but don't confuse
that with the raw image.

I understand that (some?) Nikons throw away image information in
compressed NEFs, but Canons do not do that with their CRW files. Canon
RAW files are not affected by any of the in-camera settings; they only
come into play if you are shooting jpegs. What Nikon does with their
RAW files is anyone's guess. Possibly the thrown away data in NEFs
could influence the output from those files.

Colin D.
** Posted from http://www.teranews.com **

PixelPix vehemently accused in
.
com:

On Apr 13, 12:35 am, Willarojo
wrote:
"Rita Berkowitz" vehemently accused
innews:YsmdneCCFrE4gGTanZ2dnUVZ_qvinZ2d@supernews. com:



Steve wrote:

Don't be fooled into thinking that by shooting RAW your WB
settings doesn't have any effects on the image. An
improperly set WB will result in a significantly higher
noise floor for your RAW images. This is most evident on
the blue channel. WB settings drive other key camera
settings that will affect image quality.

Ok, so please explain to me how the camera WB setting effect
the raw image other than by just recording what the WB
setting was in the EXIF data and by using it for the
embedded JPEGs?

There are many more articles, but here's a simple one.

"This article was great because it really dispels the myth
that RAW can fix everything; the camera literally captures
differently depending on its white balance setting."

http://www.ppmag.com/web-exclusives/...te-balance-the
-se cret-weapo-1.html

Maybe I just don't understand but everything I've read and
witnessed leads me to believe that the WB setting doesn't do
anything at all to the image data in the raw file.

You, like many others, erroneously assume RAW data is just
that, 100% unprocessed data from the sensor, it is not. WB
is calculated into setting many different camera parameters,
even simple ones such as how the camera exposes an image.
True, you can always change this is post, but at a cost. Set
you WB so you can intentionally blow your blue channel and
come back and tell what you find after you correct it in
post. You get more leeway with RAW than using JPG, but you
are still not getting a free lunch shooting RAW. That is why
it is so important to get it right in-camera.

Rita

Is it too late to jump in on this one?

I read the article in "ppmag" and I have a question: is the
author suggesting that because changing the color/WB sliders
while manipulating a RAW file is the same as (or at least
comparable to) varying the WB settings that were set when the
RAW was taken? Is she suggesting that post-shot processing is
directly comparable to shot-taking settings? Am I
misunderstanding this? I mean, she is comparing 2 different
conversions/manipulations of 1 RAW file, not comparing multiple
RAWs and RAW settings, right?
May I propose a (hopefully) rigorous way to examine this:
take
a series of shots of the same object/scene in the exact same
lighting conditions, but in every "basic" WB setting. In fact,
we could go further and do the same thing for every Kelvin
increment setting, I think.
If the RAW histograms are all the same, then WB does not
affect
RAW exposure; if they vary, then WB does affect exposure. We
could even estimate how much they affect exposure.
So, is WB metadata that is recorded at exposure, but does
not
directly affect; or is it a "mask" that is recorded *and*
applied at exposure?
I don't have the answer, but this clearly is an important
issue, and I certainly would like to know, so I can set my
camera properly, depending on what I hope to accomplish at any
given shoot.
Or do all y'all want to continue with the sniping, which I
must
say is terribly clever and entertaining. (Not really.)

Willa
--http://www.pbase.com/willarojo

"I came into this world, not chiefly to make this a good place
to live in, but to live in it, be it good or bad."
Thoreau, Civil Disobedience

"We are in great haste to construct a magnetic telegraph line
from Maine to Texas; but Maine and Texas, it may be, have
nothing important to communicate."
Thoreau, Walden

The test that you have suggested has been conducted and reported
on two or three times throughout this thread and WB has made
absolutely no difference to exposure while shooting RAW, as the
histograms have remained identical.


That's what I found in my own half-assed attempt at the same
experiment.
So, the rest of the thread is fluff, neh?

Willa
--
http://www.pbase.com/willarojo

“I came into this world, not chiefly to make this a good place to
live in, but to live in it, be it good or bad.”
Thoreau, Civil Disobedience

“We are in great haste to construct a magnetic telegraph line from
Maine to Texas; but Maine and Texas, it may be, have nothing
important to communicate.”
Thoreau, Walden
******
http://en.wikipedia.org/wiki/Delusional_disorder