[filmscanners] Re: color bit depth and digital cameras

2007-07-15 Thread Berry Ives
I also always shoot raw plus SHQ jpeg.  The E-1 raw is 14-bit.  Very good
insurance, and I always process the raw file for anything I'm going to
print.

Berry


On 7/14/07 9:14 AM, Bob Geoghegan [EMAIL PROTECTED] wrote:

 I wonder if the confusion comes from the option for compressed NEF as the
 raw format.  The D200 default is uncompressed  lossless but it's easy to
 change to the just barely lossy compressed option.  Compressed in-camera
 squeezes the 12 bit, 4096 native analog RAW value scale into 683 values,
 ~9.4 bits but differently allocated.  Nearly all the compression loss is in
 more highly gradated high values.  In uncompressed RAW, the top 4 stops use
 3840 (2048+1024+512+256) values of the 4096.  The remaining 256 values cover
 the rest of the 8 bits.  Compressed NEF's allocate 251 values to the lower
 256 (8 stops) and the remaining 432 to the top 4 stops (3860 raw values).
 The result is just a little less recoverable highlight data -- on average
 more values per f-stop than the lower range.  The loss seems to  empirically
 provable but hardly ever meaningful in the image.  I still shoot
 uncompressed NEFs just in case.  The D80, D70, D50  D40 bodies only have
 compressed NEF.

 http://www.photography-forums.com/t80862-drawbacks-of-compressed-nef-in-d200
 .html

 Bob G
 -Original Message-
 From: [EMAIL PROTECTED]
 [mailto:[EMAIL PROTECTED] On Behalf Of Berry Ives
 Sent: Saturday, July 14, 2007 8:05 AM
 To: [EMAIL PROTECTED]
 Subject: [filmscanners] Re: color bit depth and digital cameras

 Dpreview.com's review indicates that it is a 12-bit raw format.
 ~Berry


 On 7/13/07 11:27 PM, David J. Littleboy [EMAIL PROTECTED] wrote:


 From: [EMAIL PROTECTED]


 I was just playing with my new Nikon D200 and discovered
 something that surprised me.  Unless there is some quality
 adjustment setting I missed, it's color bit depth apparently is
 only 8 bits in NEF Raw.  By comparison, my Polaroid SprintScan
 4000 scanner has a color bit depth of 12 bits, and other scanners
 have much higher color bit depths than this.  While color bit
 depth is a commonly cited specification for scanners, I've seldom
 seen it cited for digital cameras.  Does the lower bit depth for
 the D200 imply lower quality color rendition than my 12 bit scanner?
 

 I suspect you've done something wrong. This reference


 http://www.clarkvision.com/imagedetail/digital.sensor.performance.summary/in
 de
 x.html

 Shows the D200 doing very well indeed at ISO 100. I'm quite sure it uses a
 12-bit A/D converter.

 Note that just because a camera or scanner has X bits in its A/D converter
 doesn't mean you have X bits of valid data in the output files.

 David J. Littleboy
 [EMAIL PROTECTED]
 Tokyo, Japan



 
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[filmscanners] Re: color bit depth and digital cameras

2007-07-14 Thread Berry Ives
Dpreview.com's review indicates that it is a 12-bit raw format.
~Berry


On 7/13/07 11:27 PM, David J. Littleboy [EMAIL PROTECTED] wrote:


 From: [EMAIL PROTECTED]


 I was just playing with my new Nikon D200 and discovered
 something that surprised me.  Unless there is some quality
 adjustment setting I missed, it's color bit depth apparently is
 only 8 bits in NEF Raw.  By comparison, my Polaroid SprintScan
 4000 scanner has a color bit depth of 12 bits, and other scanners
 have much higher color bit depths than this.  While color bit
 depth is a commonly cited specification for scanners, I've seldom
 seen it cited for digital cameras.  Does the lower bit depth for
 the D200 imply lower quality color rendition than my 12 bit scanner?
 

 I suspect you've done something wrong. This reference

 http://www.clarkvision.com/imagedetail/digital.sensor.performance.summary/inde
 x.html

 Shows the D200 doing very well indeed at ISO 100. I'm quite sure it uses a
 12-bit A/D converter.

 Note that just because a camera or scanner has X bits in its A/D converter
 doesn't mean you have X bits of valid data in the output files.

 David J. Littleboy
 [EMAIL PROTECTED]
 Tokyo, Japan


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[filmscanners] RE: color bit depth and digital cameras

2007-07-14 Thread Bob Geoghegan
I wonder if the confusion comes from the option for compressed NEF as the
raw format.  The D200 default is uncompressed  lossless but it's easy to
change to the just barely lossy compressed option.  Compressed in-camera
squeezes the 12 bit, 4096 native analog RAW value scale into 683 values,
~9.4 bits but differently allocated.  Nearly all the compression loss is in
more highly gradated high values.  In uncompressed RAW, the top 4 stops use
3840 (2048+1024+512+256) values of the 4096.  The remaining 256 values cover
the rest of the 8 bits.  Compressed NEF's allocate 251 values to the lower
256 (8 stops) and the remaining 432 to the top 4 stops (3860 raw values).
The result is just a little less recoverable highlight data -- on average
more values per f-stop than the lower range.  The loss seems to  empirically
provable but hardly ever meaningful in the image.  I still shoot
uncompressed NEFs just in case.  The D80, D70, D50  D40 bodies only have
compressed NEF.

http://www.photography-forums.com/t80862-drawbacks-of-compressed-nef-in-d200
.html

Bob G
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Berry Ives
Sent: Saturday, July 14, 2007 8:05 AM
To: [EMAIL PROTECTED]
Subject: [filmscanners] Re: color bit depth and digital cameras

Dpreview.com's review indicates that it is a 12-bit raw format.
~Berry


On 7/13/07 11:27 PM, David J. Littleboy [EMAIL PROTECTED] wrote:


 From: [EMAIL PROTECTED]


 I was just playing with my new Nikon D200 and discovered
 something that surprised me.  Unless there is some quality
 adjustment setting I missed, it's color bit depth apparently is
 only 8 bits in NEF Raw.  By comparison, my Polaroid SprintScan
 4000 scanner has a color bit depth of 12 bits, and other scanners
 have much higher color bit depths than this.  While color bit
 depth is a commonly cited specification for scanners, I've seldom
 seen it cited for digital cameras.  Does the lower bit depth for
 the D200 imply lower quality color rendition than my 12 bit scanner?
 

 I suspect you've done something wrong. This reference


http://www.clarkvision.com/imagedetail/digital.sensor.performance.summary/in
de
 x.html

 Shows the D200 doing very well indeed at ISO 100. I'm quite sure it uses a
 12-bit A/D converter.

 Note that just because a camera or scanner has X bits in its A/D converter
 doesn't mean you have X bits of valid data in the output files.

 David J. Littleboy
 [EMAIL PROTECTED]
 Tokyo, Japan




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[filmscanners] Re: color bit depth and digital cameras

2007-07-13 Thread gary
I can't comment on the bit depth of cameras, but scanners need more bits
when processing negative film since negative film has it's dynamic range
compressed. Eight bits was passable for slide film, well, properly
exposed slide film.

Film like Astia is slightly compressed, i.e. it doesn't have the full
dynamic range after chemical processing. It probably doesn't project
well, but it sure scans well.


[EMAIL PROTECTED] wrote:
 I was just playing with my new Nikon D200 and discovered
 something that surprised me.  Unless there is some quality
 adjustment setting I missed, it's color bit depth apparently is
 only 8 bits in NEF Raw.  By comparison, my Polaroid SprintScan
 4000 scanner has a color bit depth of 12 bits, and other scanners
 have much higher color bit depths than this.  While color bit
 depth is a commonly cited specification for scanners, I've seldom
 seen it cited for digital cameras.  Does the lower bit depth for
 the D200 imply lower quality color rendition than my 12 bit scanner?
 ___
 Dr. Paul Patton
 Life Sciences Building Rm 538A
 work: (419)-372-3858
 home: (419)-352-5523
 Biology Department
 Bowling Green State University
 Bowling Green, Ohio 43403

 The most beautiful thing we can experience is
 the mysterious.  It is the source of all true art
 and science.
 -Albert Einstein
 ___






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[filmscanners] Re: color bit depth and digital cameras

2007-07-13 Thread David J. Littleboy

From: [EMAIL PROTECTED]


I was just playing with my new Nikon D200 and discovered
something that surprised me.  Unless there is some quality
adjustment setting I missed, it's color bit depth apparently is
only 8 bits in NEF Raw.  By comparison, my Polaroid SprintScan
4000 scanner has a color bit depth of 12 bits, and other scanners
have much higher color bit depths than this.  While color bit
depth is a commonly cited specification for scanners, I've seldom
seen it cited for digital cameras.  Does the lower bit depth for
the D200 imply lower quality color rendition than my 12 bit scanner?


I suspect you've done something wrong. This reference

http://www.clarkvision.com/imagedetail/digital.sensor.performance.summary/index.html

Shows the D200 doing very well indeed at ISO 100. I'm quite sure it uses a
12-bit A/D converter.

Note that just because a camera or scanner has X bits in its A/D converter
doesn't mean you have X bits of valid data in the output files.

David J. Littleboy
[EMAIL PROTECTED]
Tokyo, Japan



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