In article , Eric Stevens
wrote:

The "RAW data file" is merely a file containing the
camera raw data. The only part of the file that relates
to the image is the data it contains. Which is to say
that we *are* talking about the "RAW data", even if you
want to call if a "RAW data file". It's the same data
either way.

Nope. What comes out of the sensor is not what is saved in the RAW
file. There is a transformation involved.

what type of transformation and from what to what?

depending on the camera, there may be minor changes such as analog
white balance or noise reduction, but for all intents the data in the
raw file *is* the data off the sensor, at least with bayer sensors.

Note that "sensor data", in the context of this
discussion, would be the analog data directly read from
the sensor ....

... what analog data?

from the sensor, before the a/d converter.

Second, in the case of the Nikon
D300 the update has changed the way in which the raw data from the
sensors have been interpreted and saved to the RAW file.

Nice try, but I just read the release notes for Nikon's
upgraded firmware for the D300, and saw exactly *nothing*
like what you are saying.

Provide details, and be specific.

What do you make of:

. Image quality: NEF (RAW ) + JPEG
. NEF (RAW) recording: Lossless compressed or Compressed
. Image size: S or M

That sounds like a change in the way raw data from the sensors have
been interpreted and saved to the RAW file.

no it doesn't. the first is embedding the jpeg in addition to the raw
data and the second is how it's compressed. the third is for the size
of the jpeg file. raw files are always full size, with canon's sraw
being an exception (and since this is a nikon d300, not applicable).

I wouldn't argue with you over what you have just said but I would
like to point out that this discussion has been about the interpolated
data saved in the RAW file.

The raw data saved in the RAW file is not interpolated.

See the last line of ...
http://en.wikipedia.org/wiki/Bayer_filter

"Bryce Bayer's patent called the green photosensors
luminance-sensitive elements and the red and blue ones
chrominance-sensitive elements. He used twice as many
green elements as red or blue to mimic the human eye's
greater resolving power with green light. These elements
are referred to as sensor elements, sensels, pixel sensors,
or simply pixels; sample values sensed by them, after
interpolation, become image pixels."

Didn't you read what that paragraph says????

Are you unable to determine that the "after
interpolation" is refering not to generation of data
that goes into the RAW file, but rather what is done
with data *from* the RAW file in order to make an image
(such as TIFF or JPEG). That is what "image pixels" means.

Haw! You really don't understand what Bayer interpolation is all
about.

if anyone doesn't understand it, it's you. nowhere in what *you*
quoted says the data in the raw *file* is interpolated.

the interpolation is done in the raw converter on the computer, long
after the raw file has been created.

The data saved in the RAW file has not yet been
interpolated, ....

How else do you reckon it is derived from the Bayer mosaic?

the data in the raw file is *before* the interpolation is done to
demosaic the image.

... and when it is interpolated it is *not*
saved in the RAW file, and is no longer considered "raw"
data.

Well, at least you understand that much.

odd, because that contradicts what you've been saying.

However, in addition to that
the JPEG image which results from interpolation simply
does not contain anything like the full amount of
information that was in the RAW file's data. You cannot
reverse the process.

HOW DO I MAKE IT CLEAR THAT FROM THE BEGINNING WE HAVE BEEN TALKING
ABOUT THE RELATIONSHIP BETWEEN THE ORIGINAL IMAGE ON THE SENSOR AND
THE 'RAW' FILE.

Then don't talk about interpolation and other software processing
of the raw data, all of which takes place on data *after* it is
placed in the RAW file.

Dingbat - interpolation is an assential part of going from the Bayer
array to the RAW data file. Please don't continue to pretend
otherwise.

no need to pretend otherwise since that's totally incorrect.

I've quoted
from the original articls, and you still keep trying to switch to
conversion from RAW to JPG. That's an entirely different question.

Then stop talking about processing the RAW data to make an image.

I haven't been. If anything I've been talking about working backwards
from the RAW data file to reconstruct the original image.

that doesn't make any sense.