dynamic range of digital, larger or smaller?

Discussion in 'Digital Photography' started by Eolake Stobblehouse, Jun 26, 2005.

  1. If you read:
    http://www.luminous-landscape.com/columns/1Ds-4x5.shtml
    .... you'll see that Mr. Briot says that he gets a *bigger* dynamic
    range from digital (Canon 1DsII) than he does from film (4x5).
    This confuses me, for everything I heard until now indicated that
    digital has a *smaller* dynamic range.
    What is your experience?
    (I have not used film since almost the last time I got laid, so I have
    nothing to compare with.)

    --
    Yours, Eolake


    http://stobblehouse.com
     
    Eolake Stobblehouse, Jun 26, 2005
    #1
    1. Advertising

  2. Eolake Stobblehouse

    Stacey Guest

    Eolake Stobblehouse wrote:

    > If you read:
    > http://www.luminous-landscape.com/columns/1Ds-4x5.shtml
    > ... you'll see that Mr. Briot says that he gets a *bigger* dynamic
    > range from digital (Canon 1DsII) than he does from film (4x5).


    Slide film I must assume?

    > This confuses me, for everything I heard until now indicated that
    > digital has a *smaller* dynamic range.
    >


    Smaller than print film for sure..

    --

    Stacey
     
    Stacey, Jun 26, 2005
    #2
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  3. Eolake Stobblehouse

    Bob Guest

    On Sun, 26 Jun 2005 21:55:26 +0100, Eolake Stobblehouse
    <> wrote:

    >If you read:
    >http://www.luminous-landscape.com/columns/1Ds-4x5.shtml
    >... you'll see that Mr. Briot says that he gets a *bigger* dynamic
    >range from digital (Canon 1DsII) than he does from film (4x5).
    >This confuses me, for everything I heard until now indicated that
    >digital has a *smaller* dynamic range.
    >What is your experience?
    >(I have not used film since almost the last time I got laid, so I have
    >nothing to compare with.)


    That's a REAL GOOD question and can generate mega threads...

    OK... it depends on the film! And on the digital cam!

    I'd say any digital can beat Kodachrome... and a web cam could probably beat
    Polaroid...

    But some modern films (is it called Velvia?) can beat digital...

    Now if you go to B/W film, that's a different story, since some films I've used
    such as Ilford have a useful range of 11 F stops or more... that's a lot....

    As for my experience - I can get lots of details out of shadows in digital, but
    I've only done color positives in the darkroom, and they come out as is, you
    might say, you can't go play with them.

    You'd have to hear from someone who has done color printing, I haven't.

    And my darkroom is closed!
     
    Bob, Jun 26, 2005
    #3
  4. Bob wrote:

    > On Sun, 26 Jun 2005 21:55:26 +0100, Eolake Stobblehouse
    > <> wrote:
    >
    >
    >>If you read:
    >>http://www.luminous-landscape.com/columns/1Ds-4x5.shtml
    >>... you'll see that Mr. Briot says that he gets a *bigger* dynamic
    >>range from digital (Canon 1DsII) than he does from film (4x5).
    >>This confuses me, for everything I heard until now indicated that
    >>digital has a *smaller* dynamic range.
    >>What is your experience?
    >>(I have not used film since almost the last time I got laid, so I have
    >>nothing to compare with.)

    >
    >
    > That's a REAL GOOD question and can generate mega threads...
    >
    > OK... it depends on the film! And on the digital cam!
    >
    > I'd say any digital can beat Kodachrome... and a web cam could probably beat
    > Polaroid...
    >
    > But some modern films (is it called Velvia?) can beat digital...


    No! Digital, has a very high dynamic range, see:

    Dynamic Range and Transfer Functions of Digital Images
    and Comparison to Film
    http://www.clarkvision.com/imagedetail/dynamicrange2

    Roger

    >
    > Now if you go to B/W film, that's a different story, since some films I've used
    > such as Ilford have a useful range of 11 F stops or more... that's a lot....
    >
    > As for my experience - I can get lots of details out of shadows in digital, but
    > I've only done color positives in the darkroom, and they come out as is, you
    > might say, you can't go play with them.
    >
    > You'd have to hear from someone who has done color printing, I haven't.
    >
    > And my darkroom is closed!
    >
     
    Roger N. Clark (change username to rnclark), Jun 27, 2005
    #4
  5. Eolake Stobblehouse

    Sheldon Guest

    "Eolake Stobblehouse" <> wrote in message
    news:260620052155262925%...
    > If you read:
    > http://www.luminous-landscape.com/columns/1Ds-4x5.shtml
    > ... you'll see that Mr. Briot says that he gets a *bigger* dynamic
    > range from digital (Canon 1DsII) than he does from film (4x5).
    > This confuses me, for everything I heard until now indicated that
    > digital has a *smaller* dynamic range.
    > What is your experience?
    > (I have not used film since almost the last time I got laid, so I have
    > nothing to compare with.)
    >
    > --
    > Yours, Eolake
    >
    >
    > http://stobblehouse.com


    I think it depends on a lot of factors, with lighting maybe being the most
    critical. I've found digital to be close to slide film. I used to print
    color, but you can do a lot more with Photoshop and it looks a lot better.
     
    Sheldon, Jun 27, 2005
    #5
  6. Eolake Stobblehouse

    Scott W Guest

    Eolake Stobblehouse wrote:
    > If you read:
    > http://www.luminous-landscape.com/columns/1Ds-4x5.shtml
    > ... you'll see that Mr. Briot says that he gets a *bigger* dynamic
    > range from digital (Canon 1DsII) than he does from film (4x5).
    > This confuses me, for everything I heard until now indicated that
    > digital has a *smaller* dynamic range.
    > What is your experience?
    > (I have not used film since almost the last time I got laid, so I have
    > nothing to compare with.)
    >
    > --
    > Yours, Eolake
    >
    >
    > http://stobblehouse.com


    It would appear that yes a good digital camera has more range then
    film, even negative film.

    Here is a photo from my 20D, not a bad exposure, this was taken at 1/60
    of a second.
    http://www.sewcon.com/photos/IMG_8207.jpg

    Here is I have taken the photo at 1/8000 of a second, 7 stop under
    exposed. The ISO and F number were left the same as the 1/60 shot.
    http://www.sewcon.com/photos/IMG_8206.jpg
    Level were adjusted to pull out as much as I could.

    I would really like to see someone take two film photos with this range
    using film and get even close to a viewable photo.

    Scott
     
    Scott W, Jun 27, 2005
    #6
  7. Eolake Stobblehouse

    Bob Guest

    On Sun, 26 Jun 2005 17:09:57 -0600, "Roger N. Clark (change username to
    rnclark)" <> wrote:

    >Bob wrote:
    >
    >> On Sun, 26 Jun 2005 21:55:26 +0100, Eolake Stobblehouse
    >> <> wrote:
    >>
    >>
    >>>If you read:
    >>>http://www.luminous-landscape.com/columns/1Ds-4x5.shtml
    >>>... you'll see that Mr. Briot says that he gets a *bigger* dynamic
    >>>range from digital (Canon 1DsII) than he does from film (4x5).
    >>>This confuses me, for everything I heard until now indicated that
    >>>digital has a *smaller* dynamic range.
    >>>What is your experience?
    >>>(I have not used film since almost the last time I got laid, so I have
    >>>nothing to compare with.)

    >>
    >>
    >> That's a REAL GOOD question and can generate mega threads...
    >>
    >> OK... it depends on the film! And on the digital cam!
    >>
    >> I'd say any digital can beat Kodachrome... and a web cam could probably beat
    >> Polaroid...
    >>
    >> But some modern films (is it called Velvia?) can beat digital...

    >
    >No! Digital, has a very high dynamic range, see:
    >
    > Dynamic Range and Transfer Functions of Digital Images
    > and Comparison to Film
    > http://www.clarkvision.com/imagedetail/dynamicrange2
    >
    >Roger


    Digital cameras have a maximum range of 12 bits since the file is 12 bits...
    scanning film with a 12 bit scanner is a waste of time... if the film was 14
    bits how would the scanner see it? That site compares 12 bit digital to a 12
    bit scan of film...

    Unfortunately I can't find the site I went to originally that tested the range
    of various films.

    >>
    >> Now if you go to B/W film, that's a different story, since some films I've used
    >> such as Ilford have a useful range of 11 F stops or more... that's a lot....
    >>
    >> As for my experience - I can get lots of details out of shadows in digital, but
    >> I've only done color positives in the darkroom, and they come out as is, you
    >> might say, you can't go play with them.
    >>
    >> You'd have to hear from someone who has done color printing, I haven't.
    >>
    >> And my darkroom is closed!
    >>
     
    Bob, Jun 27, 2005
    #7
  8. Eolake Stobblehouse

    Scott W Guest

    Bob wrote:
    > On Sun, 26 Jun 2005 17:09:57 -0600, "Roger N. Clark (change username to
    > rnclark)" <> wrote:
    >
    > >Bob wrote:
    > >
    > >> On Sun, 26 Jun 2005 21:55:26 +0100, Eolake Stobblehouse
    > >> <> wrote:
    > >>
    > >>
    > >>>If you read:
    > >>>http://www.luminous-landscape.com/columns/1Ds-4x5.shtml
    > >>>... you'll see that Mr. Briot says that he gets a *bigger* dynamic
    > >>>range from digital (Canon 1DsII) than he does from film (4x5).
    > >>>This confuses me, for everything I heard until now indicated that
    > >>>digital has a *smaller* dynamic range.
    > >>>What is your experience?
    > >>>(I have not used film since almost the last time I got laid, so I have
    > >>>nothing to compare with.)
    > >>
    > >>
    > >> That's a REAL GOOD question and can generate mega threads...
    > >>
    > >> OK... it depends on the film! And on the digital cam!
    > >>
    > >> I'd say any digital can beat Kodachrome... and a web cam could probably beat
    > >> Polaroid...
    > >>
    > >> But some modern films (is it called Velvia?) can beat digital...

    > >
    > >No! Digital, has a very high dynamic range, see:
    > >
    > > Dynamic Range and Transfer Functions of Digital Images
    > > and Comparison to Film
    > > http://www.clarkvision.com/imagedetail/dynamicrange2
    > >
    > >Roger

    >
    > Digital cameras have a maximum range of 12 bits since the file is 12 bits...
    > scanning film with a 12 bit scanner is a waste of time... if the film was 14
    > bits how would the scanner see it? That site compares 12 bit digital to a 12
    > bit scan of film...
    >
    > Unfortunately I can't find the site I went to originally that tested the range
    > of various films.
    >

    You have to be careful when talking about the range of film, there is
    the range in the film and then there is the range of light level it has
    captured, these can be very different. Slide film for example has a
    pretty large range of density, but because of its contrast the range of
    light level it can capture is very small.

    Negative film is somewhat the opposite, it has a smaller density range
    then the exposure range needed to go across its range.

    Kodak shows an exposure range of about 12 stops, but and this is a big
    but they don't talk about how large of an area of the film they are
    looking at and they don't talk about noise in the film, so it is hard
    to know what the limit is just from their plots of exposure vs film
    density.

    Note that if the digital camera really uses all 12 bits then this would
    be 12 stops of range, by this I mean that the noise is low enough that
    the bottom bit is more then just noise but is recording light levels as
    well.

    Scott
     
    Scott W, Jun 27, 2005
    #8
  9. Bob wrote:

    > On Sun, 26 Jun 2005 17:09:57 -0600, "Roger N. Clark (change username to
    > rnclark)" <> wrote:
    >
    >>Bob wrote:
    >>>But some modern films (is it called Velvia?) can beat digital...

    >>
    >>No! Digital, has a very high dynamic range, see:
    >>
    >> Dynamic Range and Transfer Functions of Digital Images
    >> and Comparison to Film
    >> http://www.clarkvision.com/imagedetail/dynamicrange2
    >>
    >>Roger

    >
    >
    > Digital cameras have a maximum range of 12 bits since the file is 12 bits...
    > scanning film with a 12 bit scanner is a waste of time... if the film was 14
    > bits how would the scanner see it? That site compares 12 bit digital to a 12
    > bit scan of film...
    >
    > Unfortunately I can't find the site I went to originally that tested the range
    > of various films.


    Let's look at the scientific plausibility of 14 bit dynamic range from film.
    By the definition and calibration of ISO we can use the full well capacity
    of digital sensors to see how many photons are being collected in a
    given exposure. E.g. see:
    http://clarkvision.com/imagedetail/digital.signal.to.noise
    and references therein.

    For an 8.2 micron pixel spacing on a 1D Mark II camera, = 67 square
    microns, the electronic sensor collects a maximum of ~52,300 electrons,
    corresponding to the brightest parts in a scene (e.g. 100% reflectance
    when the exposure is set for an 18% gray card). The CMOS sensors
    have quantum efficiencies of 25-40%. Let's assume 30%, so the photons
    incident in the green passband is about 3.3 times higher, or about
    172,000 photons per 67 square microns. The 1D Mark II sensor has a
    read noise of about 7 electrons, so the dynamic range is
    about 52,300/7 ~ 7400, or over 12.8 stops, and is thus limited by
    the 12-bit analog to digital converter electronics.

    Film, however, has only a few percent quantum efficiency, about
    3%. This in the same 67 square microns, film would convert
    only ~172,00 *0.03 = 5160 photons. If film could record every
    photon into density with no noise, it would have a dynamic range
    of only 5160 or 12.3 stops. But film is not very good. While
    a single photon may convert a single grain, one really needs a
    grain clump activated, so many grains. This is why characteristic
    curves for film have a "toe." Film needs many photons, far more than
    electronic sensors to record that first low level signal. What that
    is needs some study, but it is clearly more than 10 converted photons,
    based on comparisons to electronic sensors and their measured read noise.
    So, assuming an optimistic 10, then the dynamic range of film would be
    about 5160/10 ~ 516, or 9 stops.
    This is evident in the response curves at:
    http://clarkvision.com/imagedetail/dynamicrange2
    in Figure 8b. Note the high noise in the film at the low end.
    That is not scanner noise, but noise in the film. Now look at
    Figure 10: Kodak's characteristic curve for Kodak Gold 200. The curve
    goes much lower because they averaged over a large area in order
    to average the noise. But the curve at the low end is of no
    practical use for recording image detail.

    Scott's test is an excellent illustration of that limit:
    expose film and digital at meter and -7 stops and see which can
    pull more info out of the noise.

    On my dynamic range page (above), the images in Figure 5 clearly show
    the same effect, and that is true when examining the film with
    a loupe, or a microscope, as well as a with film scanner.

    Summary: 14-bits is way overkill for film, and many argue 12-bits
    is overkill. I argue 8-bit scans are not enough, so I scan
    all my film at 12-bits/channel because that is the next highest
    setting on film scanners above 8-bit.

    Roger
     
    Roger N. Clark (change username to rnclark), Jun 27, 2005
    #9
  10. Eolake Stobblehouse

    Stacey Guest

    Scott W wrote:

    >
    > It would appear that yes a good digital camera has more range then
    > film, even negative film.


    I disagree with that statement. Some are better than slide film but not as
    wide as color negative film.

    >
    > Here is a photo from my 20D, not a bad exposure, this was taken at 1/60
    > of a second.
    > http://www.sewcon.com/photos/IMG_8207.jpg


    Looks on the verge of over exposure to me.

    >
    > Here is I have taken the photo at 1/8000 of a second, 7 stop under
    > exposed. The ISO and F number were left the same as the 1/60 shot.
    > http://www.sewcon.com/photos/IMG_8206.jpg
    > Level were adjusted to pull out as much as I could.
    >


    I wouldn't call what you posted "viewable" or even useable.


    > I would really like to see someone take two film photos with this range
    > using film and get even close to a viewable photo.
    >


    Color negative film can deal with a BUNCH of over exposure and still produce
    a nice print. I'd say anything from 1 stop under to 3 stops over will be
    able to pull a pretty decent print from i.e. most people would never see
    the difference looking at the final prints, not a noisy useless mess like
    you displayed as an example of the dynamic range of digital. Next go 2-3
    stops over what a good meter reads with a digital camera and see what you
    have left in the highlights. Nothing! Digital is slightly better than silde
    film if you shoot RAW but it's still not even close to shooting color
    negative film.

    --

    Stacey
     
    Stacey, Jun 27, 2005
    #10
  11. Eolake Stobblehouse

    Scott W Guest

    Stacey wrote:
    > Scott W wrote:
    >
    > >
    > > It would appear that yes a good digital camera has more range then
    > > film, even negative film.

    >
    > I disagree with that statement. Some are better than slide film but not as
    > wide as color negative film.
    >
    > >
    > > Here is a photo from my 20D, not a bad exposure, this was taken at 1/60
    > > of a second.
    > > http://www.sewcon.com/photos/IMG_8207.jpg

    >
    > Looks on the verge of over exposure to me.
    >
    > >
    > > Here is I have taken the photo at 1/8000 of a second, 7 stop under
    > > exposed. The ISO and F number were left the same as the 1/60 shot.
    > > http://www.sewcon.com/photos/IMG_8206.jpg
    > > Level were adjusted to pull out as much as I could.
    > >

    >
    > I wouldn't call what you posted "viewable" or even useable.
    >
    >
    > > I would really like to see someone take two film photos with this range
    > > using film and get even close to a viewable photo.
    > >

    >
    > Color negative film can deal with a BUNCH of over exposure and still produce
    > a nice print. I'd say anything from 1 stop under to 3 stops over will be
    > able to pull a pretty decent print from i.e. most people would never see
    > the difference looking at the final prints, not a noisy useless mess like
    > you displayed as an example of the dynamic range of digital. Next go 2-3
    > stops over what a good meter reads with a digital camera and see what you
    > have left in the highlights. Nothing! Digital is slightly better than silde
    > film if you shoot RAW but it's still not even close to shooting color
    > negative film.
    >

    My two photos were shot at 7 stops apart, not the 4 you are talking
    about.
    So lets see it, let see you photos with that kind of range.
    Lets see you take two photo 7 stops apart and see what you can get from
    film.

    I rather doubt you will get any kind of image at all.

    Scott
     
    Scott W, Jun 27, 2005
    #11
  12. Eolake Stobblehouse

    Chris Brown Guest

    In article <>,
    Bob <> wrote:
    >
    >Digital cameras have a maximum range of 12 bits since the file is 12 bits...


    That's an indication of precision, not range.

    The dynamic range is the differencee between the highest intensity that
    records as black, and the lowest intensity that records as white in a single
    shot. That black will typically be recorded as zero, but you get the same
    dynamic range regardless of whether you record the white as 255 (8 bits) or
    4095 (12 bits), other things being equal. In the latter case, you just have
    more shades between them.
     
    Chris Brown, Jun 27, 2005
    #12
  13. Eolake Stobblehouse

    Chris Brown Guest

    In article <>,
    Bob <> wrote:

    >But some modern films (is it called Velvia?) can beat digital...


    Velvia has tiny dynamic range. Underexpose it by a bit, and your picture is
    often unsalvagable.

    Looks lovely when it works, but it's a right sod to expose. Not the best
    film to pick if you're looking for dynamic range, nor is any other E6 film.
    You want C41 or B&W films for a dynamic range comparison.
     
    Chris Brown, Jun 27, 2005
    #13
  14. I have done color printing, and I can tell you, it is a pain in the ass.You
    have to collect enough negatives for a printing batch, but usually your
    chemicals are kaputt before that,in B/W I could never print an acceptable
    print, I stained the paper with my fingers, my chemicals were kaputt every
    month, now I gave away my darkroom, and I have Kodak CX 7300 which is the
    best camera I've ever had,my SLR became my nightmare, of course to shoot a
    36 exp.film I needed months,I had slide films in the refrigerator for years
    unexposed, my mother was complaining on the room the papers were taking in
    the freezer (because of the hot greek climate even B/W papers were kaputt
    outside refrigerator in a few months)...Is that enough?

    --
    Tzortzakakis Dimitrios
    major in electrical engineering, freelance electrician
    FH von Iraklion-Kreta, freiberuflicher Elektriker
    dimtzort AT otenet DOT gr
    ? "Bob" <> ?????? ??? ??????
    news:...
    > On Sun, 26 Jun 2005 21:55:26 +0100, Eolake Stobblehouse
    > <> wrote:
    >
    > >If you read:
    > >http://www.luminous-landscape.com/columns/1Ds-4x5.shtml
    > >... you'll see that Mr. Briot says that he gets a *bigger* dynamic
    > >range from digital (Canon 1DsII) than he does from film (4x5).
    > >This confuses me, for everything I heard until now indicated that
    > >digital has a *smaller* dynamic range.
    > >What is your experience?
    > >(I have not used film since almost the last time I got laid, so I have
    > >nothing to compare with.)

    >
    > That's a REAL GOOD question and can generate mega threads...
    >
    > OK... it depends on the film! And on the digital cam!
    >
    > I'd say any digital can beat Kodachrome... and a web cam could probably

    beat
    > Polaroid...
    >
    > But some modern films (is it called Velvia?) can beat digital...
    >
    > Now if you go to B/W film, that's a different story, since some films I've

    used
    > such as Ilford have a useful range of 11 F stops or more... that's a

    lot....
    >
    > As for my experience - I can get lots of details out of shadows in

    digital, but
    > I've only done color positives in the darkroom, and they come out as is,

    you
    > might say, you can't go play with them.
    >
    > You'd have to hear from someone who has done color printing, I haven't.
    >
    > And my darkroom is closed!
    >
     
    Dimitrios Tzortzakakis, Jun 27, 2005
    #14
  15. Eolake Stobblehouse

    nailer Guest

    according to Fujifilm Research and Development No. 50-2005, page 5;
    Fig. 4 -dynamic range of CCD is about a half of that of a film.
    I do not know japanese, but they compare DSC at ISO 100 and a film of
    ISO 1600.


    On Mon, 27 Jun 2005 15:23:52 +0300, "Dimitrios Tzortzakakis"
    <> wrote:

    *I have done color printing, and I can tell you, it is a pain in the ass.You
    *have to collect enough negatives for a printing batch, but usually your
    *chemicals are kaputt before that,in B/W I could never print an acceptable
    *print, I stained the paper with my fingers, my chemicals were kaputt every
    *month, now I gave away my darkroom, and I have Kodak CX 7300 which is the
    *best camera I've ever had,my SLR became my nightmare, of course to shoot a
    *36 exp.film I needed months,I had slide films in the refrigerator for years
    *unexposed, my mother was complaining on the room the papers were taking in
    *the freezer (because of the hot greek climate even B/W papers were kaputt
    *outside refrigerator in a few months)...Is that enough?
     
    nailer, Jun 27, 2005
    #15
  16. Eolake Stobblehouse

    Don Stauffer Guest

    Eolake Stobblehouse wrote:
    > If you read:
    > http://www.luminous-landscape.com/columns/1Ds-4x5.shtml
    > ... you'll see that Mr. Briot says that he gets a *bigger* dynamic
    > range from digital (Canon 1DsII) than he does from film (4x5).
    > This confuses me, for everything I heard until now indicated that
    > digital has a *smaller* dynamic range.
    > What is your experience?
    > (I have not used film since almost the last time I got laid, so I have
    > nothing to compare with.)
    >



    This is a very complex question. There are several ways to measure or
    define dynamic range. Also, not all films have the same dynamic range,
    nor do all digicams. To make blanket statements is not helpful.

    Two definitions that are very much different is 1) smallest value of
    recorded signal divided into largest possible signal. A second is, max
    signal divided by noise (such as noise equivalent power or noise
    equivalent irradiance).

    The NEP thing is further complicated. Historically in electronic
    systems noise has been measured in electrical power. But in most
    electronic cameras the response to light is such that voltage or
    current, not electrical power, is proportional to incoming exposure.

    Consider also small signal dynamic range versus definition of smallest
    signal to largest signal.

    Suppose like film there is a fog level, or step response even with
    perfectly dark (zero exposure). If this value is known, it can be
    mathematically subtracted, in which case small signal SNR is more
    appropriate for dynamic range- i.e. noise level and max signal.

    Consider also that printing a hard copy results in a dynamic range far
    more limited than either the film or the digital camera. Inkjet prints
    have far less range than what camera captures. Photographic print has
    far less range than even lowest range film.
     
    Don Stauffer, Jun 27, 2005
    #16
  17. Eolake Stobblehouse

    Scott W Guest

    Chris Brown wrote:
    > In article <>,
    > Bob <> wrote:
    > >
    > >Digital cameras have a maximum range of 12 bits since the file is 12 bits...

    >
    > That's an indication of precision, not range.
    >
    > The dynamic range is the differencee between the highest intensity that
    > records as black, and the lowest intensity that records as white in a single
    > shot. That black will typically be recorded as zero, but you get the same
    > dynamic range regardless of whether you record the white as 255 (8 bits) or
    > 4095 (12 bits), other things being equal. In the latter case, you just have
    > more shades between them.


    Well no you are not right here. If we assume a linear A/D converter,
    and they are, then if you want 12 stop of range you will need at least
    a 12 bit converter. The dynmic is range is not the ratio of the
    highest to the lowest level, if the lowest is zero you would be
    dividing by zero. The dynamic range is the ratio of the highest level
    to the lowest level that is just out of the noise.

    Scott
     
    Scott W, Jun 27, 2005
    #17
  18. Eolake Stobblehouse

    Don Stauffer Guest

    Bob wrote:
    >
    > Digital cameras have a maximum range of 12 bits since the file is 12 bits...
    > scanning film with a 12 bit scanner is a waste of time... if the film was 14
    > bits how would the scanner see it? That site compares 12 bit digital to a 12
    > bit scan of film...
    >

    The digitizer quantization is only one factor in the total dynamic
    range. Suppose I have an electronic sensor that has only a four to one
    dynamic range, i.e., the max signal is only four times the noise level
    of the sensor.

    Nothing prevents me from putting this noisy signal into a 12 or even 16
    bit digitizer. Yet the result is NOT a 12 bit or 16 bit dynamic range.
    It is a 2 bit dynamic range. The sensor quality IS important when
    talking about the dynamic range of a digicam.
     
    Don Stauffer, Jun 27, 2005
    #18
  19. > Film, however, has only a few percent quantum efficiency, about
    > 3%. This in the same 67 square microns, film would convert
    > only ~172,00 *0.03 = 5160 photons. If film could record every
    > photon into density with no noise, it would have a dynamic range
    > of only 5160 or 12.3 stops. But film is not very good. While
    > a single photon may convert a single grain, one really needs a
    > grain clump activated, so many grains.


    It is widely reported in the technical film literature that 3 photons
    are required to make a crystal developable. How many photons must hit
    the grain for three to interact is another question...

    From a practical point of view, I find that using modern color negative
    film, shooting in bright daylight, I can capture the full sun in one
    part of my panoramas and get proper exposure for the rest of the scene.
    What I mean is, that the sky is captured correctly right up to the edge
    of the solar disk. This seems to indicate a pretty high tolerance for
    overexposure. I would guess somewhere in the range of 12 stops.

    I see Roger Clark's studies that digital is even better, but this
    doesn't seem to agree with most people's field experience. For example,
    this month's Petersons magazine has two articles about the limitations
    of digital dynamic range. In one the author assumes 7 stops and uses
    multiple images to extract correctly exposed regions and combine.
    In the other the discussion is about the usual tricks to minimize scene
    contrast. So it seems that working pros find digital contrast range
    similar to film transparencies.

    I don't have any explanation as to why the field results and the
    theoretical (or controlled experimental) don't seem to agree.
    Roger??

    --
    Robert D Feinman
    Landscapes, Cityscapes and Panoramic Photographs
    http://robertdfeinman.com
    mail:
     
    Robert Feinman, Jun 27, 2005
    #19
  20. nailer wrote:

    > according to Fujifilm Research and Development No. 50-2005, page 5;
    > Fig. 4 -dynamic range of CCD is about a half of that of a film.
    > I do not know japanese, but they compare DSC at ISO 100 and a film of
    > ISO 1600.


    Statements like this, even by a manufacturer, are incorrect and
    irresponsible. That is like saying motorcycles have double
    the gas mileage as cars. There are many specs for both.

    CCDs can have performance like >23,000:1 dynamic range
    (e.g. see the Apogee AP7 CCD at:
    http://www.britastro.org/vss/ccdtable.html
    to 1300:1 for the Celestron Pixel 237 CCD on the same
    above web page.

    No film has a >23,000:1 (14.5 stops!) dynamic range, when you
    define dynamic range as maximum signal/noise at full
    spatial resolution.

    The problem is that most P&S cameras have low full-well
    capacity (maximum signal) and higher read-out noise, limiting
    their dynamic range. This is shown in Table 3 at:
    http://www.clarkvision.com/imagedetail/digital.signal.to.noise
    and the dynamic range in digital cameras is mostly controlled by
    full well capacity which is proportional to pixel size.
    The larger pixel sizes in DSLRs along with better electronics result
    in higher signal-to-noise ratios and larger dynamic ranges.

    Roger
     
    Roger N. Clark (change username to rnclark), Jun 27, 2005
    #20
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