2:22 p.m.
This is a very interesting discussion, wich I have been following with great interest.
I have a question that relates to this topic.
How does bit depth ( 8 bit vs 16 bit etc.) relate to all this.We are told that 8 bit color
can give us about 16,7 million colors and 16 bit something much more (I don't wont
even try to do the calculations).I know this is only in theory but lets say you have a 8
bit image in ProPhoto RGB and one thats 16 bit in the same colorspace, is there a
difference between them as to how much part of the space they use?
What I'm trying to say is does a high bit image make a better use of a large
colorspace than the 8 bit one?
Am I missing some point here or misunderstanding something?
Thanks again for very intersting discussion.
Best regards.
Jón A Sandholt
9:35 p.m.
On Jun 1, 2005, at 6:22 AM, Jón A Sandholt wrote:
This is a very interesting discussion, wich I have
been following
with great interest.
I have a question that relates to this topic.
How does bit depth ( 8 bit vs 16 bit etc.) relate to all this.We
are told that 8 bit color can give us about 16,7 million colors and
16 bit something much more (I don't wont even try to do the
calculations).I know this is only in theory but lets say you have a
8 bit image in ProPhoto RGB and one thats 16 bit in the same
colorspace, is there a difference between them as to how much part
of the space they use?
What I'm trying to say is does a high bit image make a better use
of a large colorspace than the 8 bit one?
Am I missing some point here or misunderstanding something?
Bruce has said a number of times on various lists and to me as well
that Prophoto RGB 8-bit/channel images can take more abuse than one
might suspect. I don't have an anecdote or rule of thumb really, to
indicate when there would be a problem. There are two schools of
thought: a.) work in 8-bits/channel until you have a problem that's
related to bit-depth then start over in 16-bits/channel; b.) work in
16-bits/channel even though a fair majority of the time there may be
no point in doing so.
It really depends on what kind of work you do, what kind of edits you
do, what's in the image (gradients of course are more susceptible to
posterization than noisy areas), etc.
Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
-------------------------------------------------------------
Co-author "Real World Color Management, 2nd Edition"
Published by PeachPit Press (ISBN 0-321-26722-2)
8:46 a.m.
Jon,
There is an easy way to find out things for yourself. Open an **8-bit**
CMYK image in Photoshop, use profile conversion to move it from
ISOcoated CMYK to LStar-RGB using colorimetric rendering. Look at the
histograms of that new image. Perhaps take some screenshots. Now go
back to your original image and do the same conversion to ProPhoto or
WideGamut. Compare the histograms. You will see that you use only a
fraction of what you used in LStar-RGB. You might see a loss of details
in your image, too. When working in a large gamut like ProPhoto you
have to use 16 bit in order to keep your details.
Am 01.06.2005 um 14:22 schrieb Jón A Sandholt:
This is a very interesting discussion, wich I have
been following with
great interest.
I have a question that relates to this topic.
How does bit depth ( 8 bit vs 16 bit etc.) relate to all this.We are
told that 8 bit color can give us about 16,7 million colors and 16 bit
something much more (I don't wont even try to do the calculations).I
know this is only in theory but lets say you have a 8 bit image in
ProPhoto RGB and one thats 16 bit in the same colorspace, is there a
difference between them as to how much part of the space they use?
What I'm trying to say is does a high bit image make a better use of a
large colorspace than the 8 bit one?
Am I missing some point here or misunderstanding something?
Thanks again for very intersting discussion.
Best regards.
Jón A Sandholt
6925
days inactive
6926
days old
eci-en@lists.callassoftware.com
2 comments
3 participants
participants (3)
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Chris Murphy -
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Karsten Krüger