Are we ignored regarding dynamic range?

Discussion in 'Digital Photography' started by ThomasH, Dec 4, 2004.

  1. ThomasH

    ThomasH Guest

    We all became used to the Web sited with tests of equipment. They are
    often much better and more thorough than what we can read in the
    printed press. What we see on these pages influences our purchasing
    decisions and as it is in business: meanwhile Manufacturers "sponsor"
    these sits often to bias the tests just a bit...

    While looking at the web sites with tests of digital cameras for
    several years already I never stopped to wonder: Why they still
    fail to include all essential characteristics of the sensor and
    of the image processor. For me not just the megapixels count.
    I would like to know what is the bit depth per pixel. Or I would
    like to see a warning: "manufacturer does not disclose bit depth
    of a pixel."

    Just look at the dpreview review of Canon G6, what is considered
    a prosumer camera. Page 2 (Specifications) lists RAW mode, but
    does not specify the bit depth. It makes me angry. Same Steve
    Digicams (he mentions however that the digic processor processes
    12bit signal) and you can go on so along all review sites of rank.
    Same with (say) Nikon 8800. It has NEF and RAW modes, it says.
    And? How many bits per pixel does it deliver???

    This feature is so fundamental, so decisive. And yet is being
    mentioned only in DSLR or middle format digital back reviews.
    Why? More bits per pixel provide the so important richness of
    detail in highlight and in shadow, allows to manipulate image to
    a far larger extend. Of course, whoever ignores RAW or tiff mode
    and shoots *.jpeg, has always already lost and obtains 8bit per
    color in pixel, regardless the used gear! But the raw data and the
    tiffs support bigger depth per pixel and can deliver much richer
    image detail. Just a reminder to all who do not deal with data
    processing: Obvious calculation shows that 12bit can hold 4096
    levels of luminance, 8bit merely 256, it's 16 times more!! Even
    mere 10bit per pixel allows already for 4 times more levels of
    luminance.

    I would suggest to *always* calculate as an additional technical
    spec "image data" in megapixels. As an example lets compare two
    cameras. I took in both cases Pentax to escape the usual
    Canon/Nikon bashing. I used factor of 1024 to calculate Kbyes
    and Mbytes.
    camera A has camera B has
    6Mpix 7Mpix
    sensor 3008 x 2008 3056 x 2296
    depth 12bits per color. 8bit per color
    raw data 69.12Mbytes 53.53MBytes
    converted tiff 207.37MBytes 160.6Mbytes

    And there is the extra megapixel gone... Why everybody puts
    cameras in "megapixel categories," but never not in "image data"
    categories?

    Of course higher resolution has its merits, but I would always
    weight it against more dynamic range! If the smaller resolution
    is big enough to match the quality of my glass and to achieve
    the largest size of prints which I can do, I will rather always
    go for a camera which has better dynamic range and less pixels!
    I just would like to know... what is it!!! If not provided,
    I assume its mere 8bit per color.

    Thomas
     
    ThomasH, Dec 4, 2004
    #1
    1. Advertising

  2. ThomasH <> wrote in news::

    > whoever ignores RAW or tiff mode
    > and shoots *.jpeg, has always already lost and obtains 8bit per
    > color in pixel, regardless the used gear!


    The JPEG picture uses 8 bit gamma 2.2.
    That is just as much dynamic range as 12 bit linear.


    /Roland
     
    Roland Karlsson, Dec 4, 2004
    #2
    1. Advertising

  3. ThomasH wrote:
    > We all became used to the Web sited with tests of equipment. They are
    > often much better and more thorough than what we can read in the
    > printed press. What we see on these pages influences our purchasing
    > decisions and as it is in business: meanwhile Manufacturers "sponsor"
    > these sits often to bias the tests just a bit...
    >
    > While looking at the web sites with tests of digital cameras for
    > several years already I never stopped to wonder: Why they still
    > fail to include all essential characteristics of the sensor and
    > of the image processor. For me not just the megapixels count.
    > I would like to know what is the bit depth per pixel. Or I would
    > like to see a warning: "manufacturer does not disclose bit depth
    > of a pixel."
    >
    > Just look at the dpreview review of Canon G6, what is considered
    > a prosumer camera. Page 2 (Specifications) lists RAW mode, but
    > does not specify the bit depth. It makes me angry. Same Steve
    > Digicams (he mentions however that the digic processor processes
    > 12bit signal) and you can go on so along all review sites of rank.
    > Same with (say) Nikon 8800. It has NEF and RAW modes, it says.
    > And? How many bits per pixel does it deliver???
    >
    > This feature is so fundamental, so decisive. And yet is being
    > mentioned only in DSLR or middle format digital back reviews.
    > Why? More bits per pixel provide the so important richness of
    > detail in highlight and in shadow, allows to manipulate image to
    > a far larger extend. Of course, whoever ignores RAW or tiff mode
    > and shoots *.jpeg, has always already lost and obtains 8bit per
    > color in pixel, regardless the used gear! But the raw data and the
    > tiffs support bigger depth per pixel and can deliver much richer
    > image detail. Just a reminder to all who do not deal with data
    > processing: Obvious calculation shows that 12bit can hold 4096
    > levels of luminance, 8bit merely 256, it's 16 times more!! Even
    > mere 10bit per pixel allows already for 4 times more levels of
    > luminance.
    >
    > I would suggest to *always* calculate as an additional technical
    > spec "image data" in megapixels. As an example lets compare two
    > cameras. I took in both cases Pentax to escape the usual
    > Canon/Nikon bashing. I used factor of 1024 to calculate Kbyes
    > and Mbytes.
    > camera A has camera B has
    > 6Mpix 7Mpix
    > sensor 3008 x 2008 3056 x 2296
    > depth 12bits per color. 8bit per color
    > raw data 69.12Mbytes 53.53MBytes
    > converted tiff 207.37MBytes 160.6Mbytes
    >
    > And there is the extra megapixel gone... Why everybody puts
    > cameras in "megapixel categories," but never not in "image data"
    > categories?
    >
    > Of course higher resolution has its merits, but I would always
    > weight it against more dynamic range! If the smaller resolution
    > is big enough to match the quality of my glass and to achieve
    > the largest size of prints which I can do, I will rather always
    > go for a camera which has better dynamic range and less pixels!
    > I just would like to know... what is it!!! If not provided,
    > I assume its mere 8bit per color.
    >
    > Thomas

    Good post Thomas

    This info is gratefully received

    Aerticeus

    ps - have you given much thought the the optical zoom conversion?

    58mm on my digicam looks purty darn close to 200mm on a 35mm yet its
    called 380mm (35mm equiv) Let me know what you think on this one

    A
     
    Aerticulean Effort, Dec 4, 2004
    #3
  4. ThomasH

    Robertwgross Guest

    ThomasH wrote:
    >...How many bits per pixel does it deliver???


    Canon RAW is 12 bits per pixel.

    Don't get angry. If you see some specifications that you don't like, buy some
    other brand that you do like.

    ---Bob Gross---
     
    Robertwgross, Dec 4, 2004
    #4
  5. ThomasH

    Guest

    In message <Xns95B5E3A5E5AFEklotjohan@130.133.1.4>,
    Roland Karlsson <> wrote:

    >The JPEG picture uses 8 bit gamma 2.2.
    >That is just as much dynamic range as 12 bit linear.


    Actually, an 8-bit gamma2.2--adjusted scale has more dynamic range than
    12-bit linear. Of course, the 8-bit gamma data comes from the 12-bit
    linear, so nothing is gained, only lost, in the 12-bit linear to 8-bit
    gamma.
    --

    <>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
    John P Sheehy <>
    ><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
     
    , Dec 4, 2004
    #5
  6. ThomasH wrote:
    > We all became used to the Web sited with tests of equipment. They are
    > often much better and more thorough than what we can read in the
    > printed press. What we see on these pages influences our purchasing
    > decisions and as it is in business: meanwhile Manufacturers "sponsor"
    > these sits often to bias the tests just a bit...
    >
    > While looking at the web sites with tests of digital cameras for
    > several years already I never stopped to wonder: Why they still
    > fail to include all essential characteristics of the sensor and
    > of the image processor. For me not just the megapixels count.
    > I would like to know what is the bit depth per pixel. Or I would
    > like to see a warning: "manufacturer does not disclose bit depth
    > of a pixel."
    >
    > Just look at the dpreview review of Canon G6, what is considered
    > a prosumer camera. Page 2 (Specifications) lists RAW mode, but
    > does not specify the bit depth. It makes me angry. Same Steve
    > Digicams (he mentions however that the digic processor processes
    > 12bit signal) and you can go on so along all review sites of rank.
    > Same with (say) Nikon 8800. It has NEF and RAW modes, it says.
    > And? How many bits per pixel does it deliver???
    >
    > This feature is so fundamental, so decisive. And yet is being
    > mentioned only in DSLR or middle format digital back reviews.
    > Why? More bits per pixel provide the so important richness of
    > detail in highlight and in shadow, allows to manipulate image to
    > a far larger extend. Of course, whoever ignores RAW or tiff mode
    > and shoots *.jpeg, has always already lost and obtains 8bit per
    > color in pixel, regardless the used gear! But the raw data and the
    > tiffs support bigger depth per pixel and can deliver much richer
    > image detail. Just a reminder to all who do not deal with data
    > processing: Obvious calculation shows that 12bit can hold 4096
    > levels of luminance, 8bit merely 256, it's 16 times more!! Even
    > mere 10bit per pixel allows already for 4 times more levels of
    > luminance.
    >
    > I would suggest to *always* calculate as an additional technical
    > spec "image data" in megapixels. As an example lets compare two
    > cameras. I took in both cases Pentax to escape the usual
    > Canon/Nikon bashing. I used factor of 1024 to calculate Kbyes
    > and Mbytes.
    > camera A has camera B has
    > 6Mpix 7Mpix
    > sensor 3008 x 2008 3056 x 2296
    > depth 12bits per color. 8bit per color
    > raw data 69.12Mbytes 53.53MBytes
    > converted tiff 207.37MBytes 160.6Mbytes
    >
    > And there is the extra megapixel gone... Why everybody puts
    > cameras in "megapixel categories," but never not in "image data"
    > categories?
    >
    > Of course higher resolution has its merits, but I would always
    > weight it against more dynamic range! If the smaller resolution
    > is big enough to match the quality of my glass and to achieve
    > the largest size of prints which I can do, I will rather always
    > go for a camera which has better dynamic range and less pixels!
    > I just would like to know... what is it!!! If not provided,
    > I assume its mere 8bit per color.
    >
    > Thomas


    Personally I find looking at actual results is a much better comparison
    than stats.

    --
    Joseph Meehan

    26 + 6 = 1 It's Irish Math
     
    Joseph Meehan, Dec 4, 2004
    #6
  7. ThomasH

    None Guest

    > I would like to know what is the bit depth per pixel. Or I would

    > Of course higher resolution has its merits, but I would always
    > weight it against more dynamic range!



    Which is it you want? Dynamic range or color depth?

    Perhaps I am mistaken, but it seems that you are running the two
    together.

    As I have come to understand it, color depth is one thing; but it is not
    dynamic range as applied to photography and sensors. From what I have
    gleaned, dynamic range is a measure of how many gradations (stops) of
    luminance can be recorded sensor-wide, rather than how many gradations
    of color value can be recorded at one photo site.
     
    None, Dec 5, 2004
    #7
  8. ThomasH

    Sabineellen Guest

    Just buy a fuji camera.
     
    Sabineellen, Dec 5, 2004
    #8
  9. ThomasH

    ed Guest

    "Sabineellen" <> wrote in message
    news:...
    >
    > Just buy a fuji camera.


    Nah, for real depth buy a sigma.

    I'm sure out of all cameras the sigmas have been buried the most
     
    ed, Dec 5, 2004
    #9
  10. Aerticulean Effort wrote:
    []
    > Aerticeus
    >
    > ps - have you given much thought the the optical zoom conversion?
    >
    > 58mm on my digicam looks purty darn close to 200mm on a 35mm yet its
    > called 380mm (35mm equiv) Let me know what you think on this one
    >
    > A


    Sounds like a bad measurement or a faulty zoom - I don't think the
    specification would be that far out.

    David
     
    David J Taylor, Dec 5, 2004
    #10
  11. ThomasH

    Guest

    In message <>,
    None <> wrote:

    >From what I have
    >gleaned, dynamic range is a measure of how many gradations (stops) of
    >luminance can be recorded sensor-wide, rather than how many gradations
    >of color value can be recorded at one photo site.


    If you specifically qualify, "dynamic range of the sensor", yes, and the
    dynamic range of the camera's lowest ISO will be just slightly less, but
    at any higher ISO, the dynamic range of the output is limited on the top
    end by the cutoff point of analog to digital converter (4007 on the
    12-bit Canons), and on the bottom end by the noise.

    At the lowest ISOs, the shadow range is limited more by quantization
    than by noise.
    --

    <>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
    John P Sheehy <>
    ><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
     
    , Dec 5, 2004
    #11
  12. ThomasH

    Guest

    In message <Towsd.399$>,
    "ed" <> wrote:

    >Nah, for real depth buy a sigma.


    If you add the RAW data from the R, G, and B sensors from each pixel for
    greyscale output, the output will have very good dynamic range. The
    problem comes when you try to separate colors, giving a lot of hue
    noise.
    --

    <>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
    John P Sheehy <>
    ><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
     
    , Dec 5, 2004
    #12
  13. ThomasH

    YoYo Guest

    It would be nicer if they stated more tech info on products.

    Jpeg is about all the printers can handle, sRGB is the standard for color
    printers so you loose nothing other then options to correct errors with raw.

    If they could get the cameras to see more stops of light and the printers to
    match... then I will be happy.

    "ThomasH" <> wrote in message
    news:...
    >
    > We all became used to the Web sited with tests of equipment. They are
    > often much better and more thorough than what we can read in the
    > printed press. What we see on these pages influences our purchasing
    > decisions and as it is in business: meanwhile Manufacturers "sponsor"
    > these sits often to bias the tests just a bit...
    >
    > While looking at the web sites with tests of digital cameras for
    > several years already I never stopped to wonder: Why they still
    > fail to include all essential characteristics of the sensor and
    > of the image processor. For me not just the megapixels count.
    > I would like to know what is the bit depth per pixel. Or I would
    > like to see a warning: "manufacturer does not disclose bit depth
    > of a pixel."
    >
    > Just look at the dpreview review of Canon G6, what is considered
    > a prosumer camera. Page 2 (Specifications) lists RAW mode, but
    > does not specify the bit depth. It makes me angry. Same Steve
    > Digicams (he mentions however that the digic processor processes
    > 12bit signal) and you can go on so along all review sites of rank.
    > Same with (say) Nikon 8800. It has NEF and RAW modes, it says.
    > And? How many bits per pixel does it deliver???
    >
    > This feature is so fundamental, so decisive. And yet is being
    > mentioned only in DSLR or middle format digital back reviews.
    > Why? More bits per pixel provide the so important richness of
    > detail in highlight and in shadow, allows to manipulate image to
    > a far larger extend. Of course, whoever ignores RAW or tiff mode
    > and shoots *.jpeg, has always already lost and obtains 8bit per
    > color in pixel, regardless the used gear! But the raw data and the
    > tiffs support bigger depth per pixel and can deliver much richer
    > image detail. Just a reminder to all who do not deal with data
    > processing: Obvious calculation shows that 12bit can hold 4096
    > levels of luminance, 8bit merely 256, it's 16 times more!! Even
    > mere 10bit per pixel allows already for 4 times more levels of
    > luminance.
    >
    > I would suggest to *always* calculate as an additional technical
    > spec "image data" in megapixels. As an example lets compare two
    > cameras. I took in both cases Pentax to escape the usual
    > Canon/Nikon bashing. I used factor of 1024 to calculate Kbyes
    > and Mbytes.
    > camera A has camera B has
    > 6Mpix 7Mpix
    > sensor 3008 x 2008 3056 x 2296
    > depth 12bits per color. 8bit per color
    > raw data 69.12Mbytes 53.53MBytes
    > converted tiff 207.37MBytes 160.6Mbytes
    >
    > And there is the extra megapixel gone... Why everybody puts
    > cameras in "megapixel categories," but never not in "image data"
    > categories?
    >
    > Of course higher resolution has its merits, but I would always
    > weight it against more dynamic range! If the smaller resolution
    > is big enough to match the quality of my glass and to achieve
    > the largest size of prints which I can do, I will rather always
    > go for a camera which has better dynamic range and less pixels!
    > I just would like to know... what is it!!! If not provided,
    > I assume its mere 8bit per color.
    >
    > Thomas
     
    YoYo, Dec 5, 2004
    #13
  14. YoYo wrote:
    > It would be nicer if they stated more tech info on products.


    That would complicate things for the average consumer at whom these
    products are aimed.

    > Jpeg is about all the printers can handle, sRGB is the standard for
    > color printers so you loose nothing other then options to correct
    > errors with raw.


    No, printers only "handle" JPEG if they accept memory cards directly. I
    will let others comment on printer gamut.

    > If they could get the cameras to see more stops of light and the
    > printers to match... then I will be happy.


    Happy, perhaps, but broke!

    David
     
    David J Taylor, Dec 5, 2004
    #14
  15. ThomasH

    ThomasH Guest

    wrote:
    >
    > In message <>,
    > None <> wrote:
    >
    > > Which is it you want? Dynamic range or color depth?
    > >
    > > Perhaps I am mistaken, but it seems that you are running the two
    > > together.


    It is irrelevant which I prefer personally, your choice might
    be different. The point I am trying to make is to make aware
    of the importance of the dynamic range and to make it a habit
    to disclose this information so that everybody can make a choice.

    The majority of users, especially if not involved in data
    processing, seem to look after getting "more mega pix" and this
    is not the only factor which we should take into consideration.
    For *me* it is not even the most important feature to consider!
    Your mileage may vary.

    >
    > >From what I have
    > >gleaned, dynamic range is a measure of how many gradations (stops) of
    > >luminance can be recorded sensor-wide, rather than how many gradations
    > >of color value can be recorded at one photo site.

    >
    > If you specifically qualify, "dynamic range of the sensor", yes, and the
    > dynamic range of the camera's lowest ISO will be just slightly less, but
    > at any higher ISO, the dynamic range of the output is limited on the top
    > end by the cutoff point of analog to digital converter (4007 on the
    > 12-bit Canons), and on the bottom end by the noise.
    >
    > At the lowest ISOs, the shadow range is limited more by quantization
    > than by noise.


    Of course, calculating 2**n numbers provide only theoretical
    upper boundary numbers. In reality noise will render some of
    these possible values unusable. May I ask what is the source
    of the cutoff values declared by Canon? I like though that
    they disclose such detail.

    Thomas


    > --
    >
    > <>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
    > John P Sheehy <>
    > ><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
     
    ThomasH, Dec 5, 2004
    #15
  16. ThomasH

    bob Guest

    "David J Taylor" <> wrote in news:31h238F3aohf3U1
    @individual.net:

    > No, printers only "handle" JPEG if they accept memory cards directly. I
    > will let others comment on printer gamut.
    >


    I think (modern) Postscript printers can actually print .jpg images
    natively. An unrelated, but interesting tidbit: HPs newest color lasers
    have added a new mode. They can now print PCL, PS, and .pdf. I think the
    images in a pdf file can be stored as .jpg.

    Bob

    --
    Delete the inverse SPAM to reply
     
    bob, Dec 5, 2004
    #16
  17. ThomasH

    Guest

    In message <>,
    ThomasH <> wrote:

    >Of course, calculating 2**n numbers provide only theoretical
    >upper boundary numbers. In reality noise will render some of
    >these possible values unusable.


    >May I ask what is the source
    >of the cutoff values declared by Canon? I like though that
    >they disclose such detail.


    They don't. That's the RAW value you get when you over-expose a blank
    white wall by 10 stops (except for the dead pixels). I am writing
    applets that give stats on the RAW data, using Adobe's uncompressed .DNG
    files as a data source, reporting low values, and a full histogram for
    the entire image and each color channel.

    You can load the uncompressed .dng files into photoshop "as" .raw.

    For the 10D, the dimensions are 3088*2056, and for the 20D they are
    3522*2348.

    1 channel, 16-bit, IBMPC, click on header number box, and click "guess",
    then load.

    These are not the pure RAW values, though, because they are posterized
    by Adobe's "15-bit + 32768" system. As an additional pain, there is a
    bug in the info tool that reports 16-bit values incorrectly, posterizing
    the "info" numbers, but not the actual data. You have to convert to RGB
    for the "info" tool to work correctly.

    There are other tools that load generic 16-bit ".raw" data and correctly
    display pixel values.
    --

    <>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
    John P Sheehy <>
    ><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
     
    , Dec 5, 2004
    #17
  18. ThomasH

    Guest

    In message <Xns95B69B4FEE7E7bobatcarolnet@216.196.97.142>,
    bob <> wrote:

    >I think (modern) Postscript printers can actually print .jpg images
    >natively.


    Are there any printers that have rotation built into their drivers?

    I've always thought that it was stupid to rotate and perspective scale
    things in a raster which would be better done at print time, with the
    higher-resolution output medium.
    --

    <>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
    John P Sheehy <>
    ><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
     
    , Dec 5, 2004
    #18
  19. ThomasH

    bob Guest

    wrote in news::


    > Are there any printers that have rotation built into their drivers?


    HP DesignJets have rotation in the drivers, and scaling too. I don't know
    for sure that Postscript supports rotation, but I think it does, and it
    does support scaling.

    You cannot, as far as I know, send a .jpg to a Postscript printer from the
    command line, but that would be interesting.

    Bob

    --
    Delete the inverse SPAM to reply
     
    bob, Dec 6, 2004
    #19
  20. bob wrote:
    > "David J Taylor" <> wrote in
    > news:31h238F3aohf3U1 @individual.net:
    >
    >> No, printers only "handle" JPEG if they accept memory cards
    >> directly. I will let others comment on printer gamut.
    >>

    >
    > I think (modern) Postscript printers can actually print .jpg images
    > natively. An unrelated, but interesting tidbit: HPs newest color
    > lasers have added a new mode. They can now print PCL, PS, and .pdf. I
    > think the images in a pdf file can be stored as .jpg.
    >
    > Bob


    Fascinating. I didn't know that. It certainly makes a lot of sense
    rather than sending huge bitmaps over the line. How do they handle colour
    spaces defined in the JPEG?

    Cheers,
    David
     
    David J Taylor, Dec 6, 2004
    #20
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. c
    Replies:
    2
    Views:
    821
  2. Hans-Peter Walter
    Replies:
    3
    Views:
    1,157
    Joe Bloggs
    Jan 21, 2004
  3. Marvin Margoshes

    Dynamic range

    Marvin Margoshes, Sep 9, 2003, in forum: Digital Photography
    Replies:
    3
    Views:
    471
    Marvin Margoshes
    Sep 12, 2003
  4. Robert Feinman

    Scene range vs dynamic range

    Robert Feinman, Jun 30, 2005, in forum: Digital Photography
    Replies:
    2
    Views:
    687
    Marvin
    Jul 4, 2005
  5. Diego Balgera
    Replies:
    5
    Views:
    7,770
    Johann Lo
    Feb 8, 2008
Loading...

Share This Page