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I'm not Hershal, just a long lost
cousin,
If you downloaded the original raw file to your
computer you should still have it, when you open a raw file in any converter it
just makes a new copy of the original with the information given to it in the
converter, you did not alter the original.
you have to down load the DNG converter from the
adobe web site, I am not sure I would go there yet, I am not sure how many
companies are ready to jump on board with the DNG and as I understand it only
adobe uses it now.
----- Original Message -----
Sent: Friday, April 29, 2005 11:06
AM
Subject: Re: Compressed Raw
hi,
i've just changed shooting mode to raw. on D100
there are 2 choices. one is compressed (i think, writing is small and hard to
see in teeny lcd) i chose plain raw. opened NEF file in photoshop. amazing
array of options. i guess i should have duplicated the file first b/c it looks
like (ridiculous, extreme) changes i made while experimenting, are permanent.
b/c i went back to download the orig file from camera and it appears as
altered version.
herschel, can you say how to convert raw to DNG format
please?
tia,
maggie
On Apr 29, 2005, at 12:07 PM, herschel mair
wrote:
Raw files are actually black and white files with data about
which cell relates to which colour. All this makes a much smaller file that
a Tiff file so I guess you could call it compressed. However the data is all
there and nothing is lost in the process. Once you open that file on a
computer it converts all the black and white data into a colour image via a
process called
DE-MOSAICING using rather complicated algorithms (Each
manufacturer of camera and software have thier own version of this sofware)
so depending on whether you open the image in Photoshop or Phase One or the
maufacturers software, you could end up with quite different images. these
images are now uncompressed, bitmap-type images. They can then be saved as
uncompressed TIFF Files or even compressed TIFF files without any loss. Or
you can compress them into JPEG files and choose how much quality you want
to lose. Either way you should convert your raw images into the universal
DNG format for posterity.
herschel
Llorenç
Herrera <lha@xxxxxxxxxxxxx> wrote:
Hi,
this is correct about Nikon D-70, it compresses de RAW files. But it’s a
non-degrading compression, nothing related to JPEG compression. It means
that those RAW compression does not affects in any way the final image
quality.
JPG,
MPEG, MP3, OOG … etc. are all degrading-type compression techniques. The
final result shows imperfections when looked very near (or heard paying
lot of attention)
LZW,
ZIP, RAR, Compressed-TIFF … etc are all NON-degrading-type compressiong
techniques. The final result shows EXACTLY the same digital data you can
see if it weren’t compressed.
I
don’t know exactly, but I bet that the kind of internal compression Nikon
uses on its RAW files is one kind of LZW.
I
don’t know anything about Nikon D100
__________________
Llorenç
Herrera Aznar
http://www.lorenzoherrera.com
http://www.fotopunto.com
De:
owner-photoforum@xxxxxxxxxxxxxxxxxxxxxx
[mailto:owner-photoforum@xxxxxxxxxxxxxxxxxxxxxx] En nombre de Jerry McCown
Enviado
el:
viernes, 29 de abril de 2005 0:02
Para:
List for Photo/Imaging Educators - Professionals - Students
Asunto:
Compressed Raw
My
D100 default setting is compressed raw and I had to go in and turn the
compression off as it was taking WAY too long to save the file.
LScottPht@xxxxxxx
wrote:
With
the Nikon D70, the RAW images are compressed RAW images. I will have to go
back and look at my manual, but I think it even says so in the manual. I'm
not sure why the camera shoots compressed RAW images, perhaps others here
could answer that.
Leslie
I don't think this is
correct, RAW files are not compressed from what I understand
Herschel
Mair
H.O.D. Photography Dept, Higher College of Technology
Al
Khuwair
Sultinate of Oman
9899673
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