"False" color using DCRAW??

Hi everybody,
I shooted many picture with my Nikon D50 in raw format.
I elaborated these with some software and in particular with dcraw
(that i suggest to you). But I have a problem. The output colors
produced by dcraw are different if I use the flag "-e" (to make a
"thumbnail") when I I don't use this flag.
Can you explain me why? (I'm a rookie). And can you explain how I can
shot picture with a embeded profile?

For help you, I use dcraw with this sintax "dcraw -v -w -p embed -T
my file.nef" and this is the output:

"Loading NIKON D50 image from my file.NEF ...
Scaling with black 0, multipliers 2.073930 1.000000 1.490272 1.000000
AHD interpolation...
my file has no embedded profile.
Converting to sRGB colorspace...
Writing data to my file.tiff ..."

Thanks in advance for you suggestion.

Bye!!

AM.

On Sep 19, 7:32 pm, Teckman wrote:
Hi everybody,
I shooted many picture with my Nikon D50 in raw format.
I elaborated these with some software and in particular with dcraw
(that i suggest to you). But I have a problem. The output colors
produced by dcraw are different if I use the flag "-e" (to make a
"thumbnail") when I I don't use this flag.
Can you explain me why? (I'm a rookie).

Hello. What dcraw -e does is to extract a thumbnail already embedded
into the raw file by the camera. That is, when you take a shot and you
have the camera set to raw, the camera saves not only the raw data but
also prepares a complete jpeg file and saves it inside the raw file.
dcraw -e doesn't convert the raw data but simply extracts this already-
existing jpeg and saves it separately.

The jpeg rendering produced by the camera does take into account white
balance, sharpening, contrast etc settings. If you use dcraw to
convert the raw data, it ignores these (except white balance, which
however is interpreted slightly differently by dcraw than by the
camera). This is why you get different colours, contrast and so on if
you use -e.

I don't understand the last part of your question,
And can you explain how I can
shot picture with a embeded profile?

can you please explain it again so I can try to help? eg what do you
mean here by profile?


For help you, I use dcraw with this sintax "dcraw -v -w -p embed -T
my file.nef" and this is the output:

"Loading NIKON D50 image from my file.NEF ...
Scaling with black 0, multipliers 2.073930 1.000000 1.490272 1.000000
AHD interpolation...
my file has no embedded profile.
Converting to sRGB colorspace...
Writing data to my file.tiff ..."

On 19 Set, 19:53, acl wrote:
On Sep 19, 7:32 pm, Teckman wrote:

Hi everybody,
I shooted many picture with my Nikon D50 in raw format.
I elaborated these with some software and in particular with dcraw
(that i suggest to you). But I have a problem. The output colors
produced by dcraw are different if I use the flag "-e" (to make a
"thumbnail") when I I don't use this flag.
Can you explain me why? (I'm a rookie).

Hello. What dcraw -e does is to extract a thumbnail already embedded
into the raw file by the camera. That is, when you take a shot and you
have the camera set to raw, the camera saves not only the raw data but
also prepares a complete jpeg file and saves it inside the raw file.
dcraw -e doesn't convert the raw data but simply extracts this already-
existing jpeg and saves it separately.

The jpeg rendering produced by the camera does take into account white
balance, sharpening, contrast etc settings. If you use dcraw to
convert the raw data, it ignores these (except white balance, which
however is interpreted slightly differently by dcraw than by the
camera). This is why you get different colours, contrast and so on if
you use -e.

I don't understand the last part of your question,

And can you explain how I can
shot picture with a embeded profile?

can you please explain it again so I can try to help? eg what do you
mean here by profile?





For help you, I use dcraw with this sintax "dcraw -v -w -p embed -T
my file.nef" and this is the output:

"Loading NIKON D50 image from my file.NEF ...
Scaling with black 0, multipliers 2.073930 1.000000 1.490272 1.000000
AHD interpolation...
my file has no embedded profile.
Converting to sRGB colorspace...
Writing data to my file.tiff ..."- Nascondi testo tra virgolette -

- Mostra testo tra virgolette -


My question is borned because if a used differert RAW renderer I
obtain different color. And before start to elaborate my shoot I would
undestand how obtained the "original" shoot. I suppose the original
picture is which obtained by original Nikon software that is ugual at
the picture obtain with flag "-e" (about color only).

Probably my right question is: "Which are the right flags just to
force DCRAW to renderer the picture how was shooted?".

Thanks for you previous answer (was quick and helpfull).

Bye.
AM.

On Sep 20, 3:18 pm, Teckman wrote:

My question is borned because if a used differert RAW renderer I
obtain different color. And before start to elaborate my shoot I would
undestand how obtained the "original" shoot. I suppose the original
picture is which obtained by original Nikon software that is ugual at
the picture obtain with flag "-e" (about color only).

Probably my right question is: "Which are the right flags just to
force DCRAW to renderer the picture how was shooted?".


OK now I see. Well, the jpeg produced by the camera is one way of
rendering it. If you like it, the closest is probably by Nikon
software (Nikon capture, View NX which is free, etc-not in Linux,
though), which does take into account the various choices you made in
camera regarding sharpening, contrast etc. Other converters render
things differently (most do a lot more than just interpolating) and,
as far as I know, all ignore these settings.

So there's no easy answer to your question (probably there's no
answer). You'll have to either process the file afterwards in Gimp/
photoshop (say), or switch to a different converter. If you're on
windows (or mac), try nikon view nx, it's free and does a good job.

Thanks for you previous answer (was quick and helpfull).

Bye.
AM.

acl wrote:
On Sep 20, 3:18 pm, Teckman wrote:

My question is borned because if a used differert RAW renderer I
obtain different color. And before start to elaborate my shoot I would
undestand how obtained the "original" shoot. I suppose the original
picture is which obtained by original Nikon software that is ugual at
the picture obtain with flag "-e" (about color only).

Probably my right question is: "Which are the right flags just to
force DCRAW to renderer the picture how was shooted?".


OK now I see. Well, the jpeg produced by the camera is one way of
rendering it. If you like it, the closest is probably by Nikon
software (Nikon capture, View NX which is free, etc-not in Linux,
though), which does take into account the various choices you made in
camera regarding sharpening, contrast etc. Other converters render
things differently (most do a lot more than just interpolating) and,
as far as I know, all ignore these settings.

So there's no easy answer to your question (probably there's no
answer). You'll have to either process the file afterwards in Gimp/
photoshop (say), or switch to a different converter. If you're on
windows (or mac), try nikon view nx, it's free and does a good job.

Use UFRAW, which is a configurable GUI/batch front end
for dcraw.

To include sharpening, USM, or whatever, it can be
post-processed with ImageMagick's "convert" program if
batch mode is needed.

With UFRAW it is fairly easy to duplicate the camera
defaults. The configuration can be saved and UFRAW can
then be invoked, for example in batch mode, using that
configuration.

The only catch is that... well to be honest it won't
take long before discarding the idea that a camera
produced JPEG is the "original" by default. Nikon of
course goes to a lot of effort to select defaults that
will at least be pleasant to most people, but there is
never anything nearly as good as a personal touch to
make an image look exactly the way the photographer
thinks it should look.

Thanks for you previous answer (was quick and helpfull).

Bye.
AM.

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