ISO and actual sensitivity in DSLR's (D70, *istD, 20D, S3...)

Discussion in 'Digital Photography' started by Alan Browne, Mar 25, 2005.

  1. Alan Browne

    Alan Browne Guest

    We've seen the occasional postings about the ISO setting and the actual
    sensitivity.

    I picked up Casseur D'Images (No. 271, March 2005) and among other
    things they did tests on a variety of DSLR's and one ZLR. (p. 169)

    They rounded the results when close to the standard 1/3. But where a
    little less clear cut, they put a +/- to indicate not quite in the 1/3 zone.

    They describe, in punishing detail, the test method, references, math,
    etc. Unfortunately, the 7D is not part of the grouping, but I'll take
    sollace in the A200 results. Minolta have long been known for their
    consistency in metering and exposure.

    [There is also an article on the S3 and I'll summarize tomorrow]

    Cheers,
    Alan.

    D70:
    Setting: 200 400 800 1600
    Actual: 160 320 640 1250


    A200 (Minolta ZLR):
    Setting: 50 100 200 400 800
    Actual: 50+ 100 200 400 800


    *istD:
    Setting: 200 400 800 1600 3200
    Actual: 250 500 1250- 2000 4000-


    20D:
    Setting: 100 200 400 800 1600 3200
    Actual: 125 250 500 1000 2000 4000


    S3:
    Setting: 100 160 200 400 800 1600
    Actual: 80 160 160+ 320 640+ 1250


    1D Mk II
    Setting: (L)50 100 200 400 800 1600 (H) 3200
    Actual 64 160 320 640 1250 2500 4000


    --
    -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
    -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
    -- [SI] gallery & rulz: http://www.pbase.com/shootin
    -- e-meil: there's no such thing as a FreeLunch.
    Alan Browne, Mar 25, 2005
    #1
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  2. Alan Browne

    Alan Browne Guest

    Alan Browne wrote:

    > I picked up Casseur D'Images (No. 271, March 2005) and among other

    Chasseur D'Images
    Alan Browne, Mar 25, 2005
    #2
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  3. Alan Browne

    Pete D Guest

    And as has been said before, it does not matter one tiny little jot as long
    as the photos come out right.

    "Alan Browne" <> wrote in message
    news:d202ab$rmr$...
    >
    > We've seen the occasional postings about the ISO setting and the actual
    > sensitivity.
    >
    > I picked up Casseur D'Images (No. 271, March 2005) and among other things
    > they did tests on a variety of DSLR's and one ZLR. (p. 169)
    >
    > They rounded the results when close to the standard 1/3. But where a
    > little less clear cut, they put a +/- to indicate not quite in the 1/3
    > zone.
    >
    > They describe, in punishing detail, the test method, references, math,
    > etc. Unfortunately, the 7D is not part of the grouping, but I'll take
    > sollace in the A200 results. Minolta have long been known for their
    > consistency in metering and exposure.
    >
    > [There is also an article on the S3 and I'll summarize tomorrow]
    >
    > Cheers,
    > Alan.
    >
    > D70:
    > Setting: 200 400 800 1600
    > Actual: 160 320 640 1250
    >
    >
    > A200 (Minolta ZLR):
    > Setting: 50 100 200 400 800
    > Actual: 50+ 100 200 400 800
    >
    >
    > *istD:
    > Setting: 200 400 800 1600 3200
    > Actual: 250 500 1250- 2000 4000-
    >
    >
    > 20D:
    > Setting: 100 200 400 800 1600 3200
    > Actual: 125 250 500 1000 2000 4000
    >
    >
    > S3:
    > Setting: 100 160 200 400 800 1600
    > Actual: 80 160 160+ 320 640+ 1250
    >
    >
    > 1D Mk II
    > Setting: (L)50 100 200 400 800 1600 (H) 3200
    > Actual 64 160 320 640 1250 2500 4000
    >
    >
    > --
    > -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
    > -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
    > -- [SI] gallery & rulz: http://www.pbase.com/shootin
    > -- e-meil: there's no such thing as a FreeLunch.
    Pete D, Mar 25, 2005
    #3
  4. In article <MdO0e.11056$>,
    "Pete D" <> wrote:

    > And as has been said before, it does not matter one tiny little jot as long
    > as the photos come out right.
    >


    The table shouldn't be interpreted as good or bad, but informational.
    Built-in exposure meters can't be used for all conditions.
    Kevin McMurtrie, Mar 25, 2005
    #4
  5. "Pete D" <> wrote in
    news:MdO0e.11056$:

    > And as has been said before, it does not matter one tiny little jot as
    > long as the photos come out right.


    You are not of the old school I see :)

    It does matter.
    - if you use an external meter.
    - when comparing the sensitivity of camera systems.
    - when using external flash.
    - etc

    But - if you just take pictures and like them - then
    the technicalities behind the making of the photo is
    of course uninteresting.

    But - it does matter - even if you don't care :)


    /Roland
    Roland Karlsson, Mar 25, 2005
    #5
  6. Alan Browne

    Owamanga Guest

    On 25 Mar 2005 10:54:52 GMT, Roland Karlsson
    <> wrote:

    >"Pete D" <> wrote in
    >news:MdO0e.11056$:
    >
    >> And as has been said before, it does not matter one tiny little jot as
    >> long as the photos come out right.

    >
    >You are not of the old school I see :)
    >
    >It does matter.
    >- if you use an external meter.
    >- when comparing the sensitivity of camera systems.
    >- when using external flash.
    >- etc


    Okay, but whether it be by table or experience, if you find your
    camera to consistently meter under or over, you'd just adjust the
    exposure accordingly wouldn't you?

    ....annoying if you switch between brands all the time, but for a
    single DSLR body owner, no biggie.

    And the report (or Alan) missed another significant angle here:

    The D70 they used, is it the same as my D70? What's the consistency of
    metering within each model like? If it's bad for any particular model,
    their table becomes fairly irrelevant.

    --
    Owamanga!
    http://www.pbase.com/owamanga
    Owamanga, Mar 25, 2005
    #6
  7. Alan Browne

    Alan Browne Guest

    Alan Browne, Mar 25, 2005
    #7
  8. Alan Browne

    Alan Browne Guest

    Roland Karlsson wrote:

    > "Pete D" <> wrote in
    > news:MdO0e.11056$:
    >
    >
    >>And as has been said before, it does not matter one tiny little jot as
    >>long as the photos come out right.

    >
    >
    > You are not of the old school I see :)
    >
    > It does matter.
    > - if you use an external meter.


    I do that.

    > - when comparing the sensitivity of camera systems.


    One of the roles of this NG.

    > - when using external flash.


    I do that too.

    > - etc
    >
    > But - if you just take pictures and like them - then
    > the technicalities behind the making of the photo is
    > of course uninteresting.


    er, this is an equipment group. This *is* one of the things we discuss
    here.

    --
    -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
    -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
    -- [SI] gallery & rulz: http://www.pbase.com/shootin
    -- e-meil: there's no such thing as a FreeLunch.
    Alan Browne, Mar 25, 2005
    #8
  9. Alan Browne

    Alan Browne Guest

    Owamanga wrote:

    > The D70 they used, is it the same as my D70? What's the consistency of
    > metering within each model like? If it's bad for any particular model,
    > their table becomes fairly irrelevant.


    They don't mention if they're using samples of one or more.

    If one were talking about lens variations (sharpness) I would agree.
    But metering in electronic cameras and shutter speeds have become quite
    precise and consistent over the past 10+ years.

    --
    -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
    -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
    -- [SI] gallery & rulz: http://www.pbase.com/shootin
    -- e-meil: there's no such thing as a FreeLunch.
    Alan Browne, Mar 25, 2005
    #9
  10. "Alan Browne" <> wrote:
    > Pete D wrote:
    >
    > > And as has been said before, it does not matter one tiny little jot as

    long
    > > as the photos come out right.

    >
    > For those who use an incident meter or seperate spot meters (including
    > myself), such information is useful.


    Not really. You have to calibrate your meter against the histograms that
    result in your camera.

    And I suspect that the results are simply random, since presumably they used
    matrix/evaluative metering which is, in principle, completely random and
    unpredictable (assuming it does what they say it does<g>).

    David J. Littleboy
    Tokyo, Japan
    David J. Littleboy, Mar 25, 2005
    #10
  11. Alan Browne

    Owamanga Guest

    On Fri, 25 Mar 2005 22:42:43 +0900, "David J. Littleboy"
    <> wrote:

    >
    >"Alan Browne" <> wrote:
    >> Pete D wrote:
    >>
    >> > And as has been said before, it does not matter one tiny little jot as

    >long
    >> > as the photos come out right.

    >>
    >> For those who use an incident meter or seperate spot meters (including
    >> myself), such information is useful.

    >
    >Not really. You have to calibrate your meter against the histograms that
    >result in your camera.
    >
    >And I suspect that the results are simply random, since presumably they used
    >matrix/evaluative metering which is, in principle, completely random and
    >unpredictable (assuming it does what they say it does<g>).


    So, the database of 30,000 images is a big lie, it's just a
    pseudo-random number generator.

    That actually explains a lot.

    I've done some tests with the D70, if my daughter (caucasian), pulls
    her face to make her eyes to look more asian, the matrix metering is a
    lot more accurate. I guess she suddenly matches some of the faces in
    the database.

    <g>

    --
    Owamanga!
    http://www.pbase.com/owamanga
    Owamanga, Mar 25, 2005
    #11
  12. In article <d214ef$cs3$>,
    David J. Littleboy <> wrote:
    >"Alan Browne" <> wrote:
    >> For those who use an incident meter or seperate spot meters (including
    >> myself), such information is useful.

    >
    >Not really. You have to calibrate your meter against the histograms that
    >result in your camera.
    >
    >And I suspect that the results are simply random, since presumably they used
    >matrix/evaluative metering which is, in principle, completely random and
    >unpredictable (assuming it does what they say it does<g>).


    What does the sensitivity of a sensor have to do with the built-in lightmeter
    of a camera?


    --
    That was it. Done. The faulty Monk was turned out into the desert where it
    could believe what it liked, including the idea that it had been hard done
    by. It was allowed to keep its horse, since horses were so cheap to make.
    -- Douglas Adams in Dirk Gently's Holistic Detective Agency
    Philip Homburg, Mar 25, 2005
    #12
  13. Alan Browne

    Owamanga Guest

    On Fri, 25 Mar 2005 15:20:24 +0100, (Philip
    Homburg) wrote:

    >In article <d214ef$cs3$>,
    >David J. Littleboy <> wrote:
    >>"Alan Browne" <> wrote:
    >>> For those who use an incident meter or seperate spot meters (including
    >>> myself), such information is useful.

    >>
    >>Not really. You have to calibrate your meter against the histograms that
    >>result in your camera.
    >>
    >>And I suspect that the results are simply random, since presumably they used
    >>matrix/evaluative metering which is, in principle, completely random and
    >>unpredictable (assuming it does what they say it does<g>).

    >
    >What does the sensitivity of a sensor have to do with the built-in lightmeter
    >of a camera?


    Are you talking histograms here? One assumes the manufacturer is
    completely aware of the exact sensitivity of the sensor, and so takes
    this into account when drawing the histogram.

    So, compare external meter reading's suggestion of exposure values for
    a given ISO to the resulting histogram at those same exposure values
    to see if an adjustment to the meter's ISO setting is required to make
    it 'accurate' for that sensor. Personally, I wouldn't trust my
    interpretation of the histogram to not introduce yet another error
    factor using this method.

    --
    Owamanga!
    http://www.pbase.com/owamanga
    Owamanga, Mar 25, 2005
    #13
  14. Alan Browne <> wrote in news:d213jh$iuf$2
    @inews.gazeta.pl:

    > er, this is an equipment group. This *is* one of the things we discuss
    > here.


    Alan - I just tried to be nice to Pete.

    Personally I fully agree with you. I just acknowledged
    that not everyone do. And that is OK IMHO.


    /Roland
    Roland Karlsson, Mar 25, 2005
    #14
  15. Alan Browne

    Alan Browne Guest

    David J Taylor wrote:

    > Alan Browne wrote:
    > []
    >
    >>er, this is an equipment group. This *is* one of the things we
    >>discuss here.

    >
    >
    > "This" is cross-posted, so it's not even one group.....


    Both groups are equipment related. I apologize for my use of the
    singular above and trust that the flogging, while justly deserved, will
    be administered mercifully.

    --
    -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
    -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
    -- [SI] gallery & rulz: http://www.pbase.com/shootin
    -- e-meil: there's no such thing as a FreeLunch.
    Alan Browne, Mar 25, 2005
    #15
  16. Alan Browne

    Alan Browne Guest

    Roland Karlsson wrote:

    > Alan Browne <> wrote in news:d213jh$iuf$2
    > @inews.gazeta.pl:
    >
    >
    >>er, this is an equipment group. This *is* one of the things we discuss
    >>here.

    >
    >
    > Alan - I just tried to be nice to Pete.
    >
    > Personally I fully agree with you. I just acknowledged
    > that not everyone do. And that is OK IMHO.


    Appolgies, I thought you were replying to me. My news reader does a bad
    job of organizing refreshes.

    Cheers,
    Alan

    --
    -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
    -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
    -- [SI] gallery & rulz: http://www.pbase.com/shootin
    -- e-meil: there's no such thing as a FreeLunch.
    Alan Browne, Mar 25, 2005
    #16
  17. Alan Browne

    McLeod Guest

    On Fri, 25 Mar 2005 08:25:09 -0500, Alan Browne
    <> wrote:

    >For those who use an incident meter or seperate spot meters (including
    >myself), such information is useful.


    And if you have time to incident meter, you probably have time to look
    at the histogram and adjust accordingly, as well.
    McLeod, Mar 25, 2005
    #17
  18. In article <>,
    Owamanga <owamanga(not-this-bit)@hotmail.com> wrote:
    >On Fri, 25 Mar 2005 15:20:24 +0100, (Philip
    >Homburg) wrote:
    >>What does the sensitivity of a sensor have to do with the built-in lightmeter
    >>of a camera?

    >
    >Are you talking histograms here? One assumes the manufacturer is
    >completely aware of the exact sensitivity of the sensor, and so takes
    >this into account when drawing the histogram.


    I think you can also show a histogram if you are completely unaware of
    the effective sensitivity of the sensor.

    The histogram is supposed to reflect the distribution of the RGB values
    on an image. How the image was obtained is not revelevant for the histogram
    (though the color space might be if you want to show brightness)


    --
    That was it. Done. The faulty Monk was turned out into the desert where it
    could believe what it liked, including the idea that it had been hard done
    by. It was allowed to keep its horse, since horses were so cheap to make.
    -- Douglas Adams in Dirk Gently's Holistic Detective Agency
    Philip Homburg, Mar 25, 2005
    #18
  19. Alan Browne

    Alan Browne Guest

    McLeod wrote:
    > On Fri, 25 Mar 2005 08:25:09 -0500, Alan Browne
    > <> wrote:
    >
    >
    >>For those who use an incident meter or seperate spot meters (including
    >>myself), such information is useful.

    >
    >
    > And if you have time to incident meter, you probably have time to look
    > at the histogram and adjust accordingly, as well.


    Quicker to set strobes with an incident flash meter. Though I am
    developing a worrisome, guilt inducing chimping habit when outdoors with
    the D7.

    Cheers,
    Alan.
    --
    -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
    -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
    -- [SI] gallery & rulz: http://www.pbase.com/shootin
    -- e-meil: there's no such thing as a FreeLunch.
    Alan Browne, Mar 25, 2005
    #19
  20. Alan Browne

    Jan Böhme Guest

    On Thu, 24 Mar 2005 23:02:51 -0500, Alan Browne
    <> wrote:

    >Alan Browne wrote:
    >
    >> I picked up Casseur D'Images (No. 271, March 2005) and among other

    > Chasseur D'Images


    No need for correction. It was much more fun as it read first.

    Jan Böhme
    Korrekta personuppgifter är att betrakta som journalistik.
    Felaktigheter utgör naturligtvis skönlitteratur.
    Jan Böhme, Mar 25, 2005
    #20
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