Another Depth of Field Question

Discussion in 'Digital Photography' started by Jules Vide, Jul 15, 2006.

  1. Jules Vide

    Jules Vide Guest

    If depth of field is the degree to which foreground, subject, and
    background remain in focus, then is depth of field a misnomer? If all
    three remain in focus, isn't that sort of anti-depth of field? Is
    there another term--for lack of better articulation, I'll call it a
    "3-D quality"--photographers use to describe the ability of a camera to
    mimic the capacity of the human eye to perceive the actual "depth" in
    any old field?
     
    Jules Vide, Jul 15, 2006
    #1
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  2. Jules Vide

    Marvin Guest

    Jules Vide wrote:
    > If depth of field is the degree to which foreground, subject, and
    > background remain in focus, then is depth of field a misnomer? If all
    > three remain in focus, isn't that sort of anti-depth of field? Is
    > there another term--for lack of better articulation, I'll call it a
    > "3-D quality"--photographers use to describe the ability of a camera to
    > mimic the capacity of the human eye to perceive the actual "depth" in
    > any old field?
    >

    The brain assembles several images from the eye to form a
    scene. If you could somehow interrupt that assembly process
    and see look at a single image, it would have the same kind
    of depth of field property as an image from a camera.

    The meaning of depth of field in optics and photography is
    rather precisely defined. See, for example,
    http://en.wikipedia.org/wiki/Depth-of-field/.
     
    Marvin, Jul 15, 2006
    #2
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  3. Jules Vide

    minnesotti Guest

    Jules Vide wrote:
    > Is
    > there another term... photographers use to describe the ability of a camera to
    > mimic the capacity of the human eye to perceive the actual "depth" in
    > any old field?


    You seem to be an avid reader. Read about the term "bokeh", e.g. in
    here -- http://www.kenrockwell.com/tech/bokeh.htm
     
    minnesotti, Jul 15, 2006
    #3
  4. Jules Vide

    jeremy Guest

    "Jules Vide" <> wrote in message
    news:...

    > Is there another term--for lack of better articulation, I'll call it a
    > "3-D quality"--photographers use to describe the ability of a camera to
    > mimic the capacity of the human eye to perceive the actual "depth" in
    > any old field?
    >


    Might you be referring to what is often called, "The Leica Glow?"

    See this link for examples:

    http://www.luminous-landscape.com/columns/sm-02-04-28.shtml
     
    jeremy, Jul 15, 2006
    #4
  5. Jules Vide

    Paul Mitchum Guest

    Jules Vide <> wrote:

    > If depth of field is the degree to which foreground, subject, and
    > background remain in focus, then is depth of field a misnomer?


    Nope. :)

    Actually, depth of field is the extent to which objects appear sharp in
    the print. But your definition is close enough for practical purposes.

    The 'field' is an area in front of and behind the object in focus. As
    the field shrinks (by, say, opening the aperture), it's depth narrows.
    The depth of the field changes. Close the aperture and it gets wider.

    > If all three remain in focus, isn't that sort of anti-depth of field?


    Nope. :) It's just a large depth of field. It's possible to have a
    depth of field so large that it encompasses all elements of the image.

    As an aside: There's a technique involving what is called the
    'hyperfocal distance,' which allows you to maximize aperture size and
    depth of field at the same time. Google it. Learning how hyperfocal
    distance works will teach you how depth of field works.

    > Is there another term--for lack of better articulation, I'll call it a
    > "3-D quality"--photographers use to describe the ability of a camera to
    > mimic the capacity of the human eye to perceive the actual "depth" in any
    > old field?


    A narrow depth of field focused on a near-field object, with the
    background all fuzzy is a standard technique. To use it, you open up the
    aperture and focus on the near-field object.
     
    Paul Mitchum, Jul 15, 2006
    #5
  6. Jules Vide

    Jules Vide Guest

    minnesotti wrote:
    >
    > You seem to be an avid reader. Read about the term "bokeh", e.g. in
    > here -- http://www.kenrockwell.com/tech/bokeh.htm


    Thanks, but as of yet I am far too uninformed about photography in
    general to appreciate the nuances of this (obviously) professional site.
     
    Jules Vide, Jul 15, 2006
    #6
  7. Jules Vide

    Jules Vide Guest

    Paul Mitchum wrote:
    >
    > Actually, depth of field is the extent to which objects appear sharp in
    > the print. But your definition is close enough for practical purposes.


    [SNIP HELPFUL CLARIFICATION]

    > A narrow depth of field focused on a near-field object, with the
    > background all fuzzy is a standard technique. To use it, you open up the
    > aperture and focus on the near-field object.


    Am I right or wrong in assuming you can't do this with a p&s camera,
    even if the camera has a setting called aperture priority?
     
    Jules Vide, Jul 15, 2006
    #7
  8. Jules Vide

    John Bean Guest

    On 15 Jul 2006 13:29:38 -0700, "Jules Vide"
    <> wrote:

    >Paul Mitchum wrote:
    >>
    >> Actually, depth of field is the extent to which objects appear sharp in
    >> the print. But your definition is close enough for practical purposes.

    >
    >[SNIP HELPFUL CLARIFICATION]
    >
    >> A narrow depth of field focused on a near-field object, with the
    >> background all fuzzy is a standard technique. To use it, you open up the
    >> aperture and focus on the near-field object.

    >
    >Am I right or wrong in assuming you can't do this with a p&s camera,
    >even if the camera has a setting called aperture priority?


    You're wrong. It's not as easy or flexible to do with
    small-sensor cameras but if the point of focus is close
    and/or a longer focal length is used it's perfectly
    possible, and something I do quite often.

    --
    John Bean
     
    John Bean, Jul 15, 2006
    #8
  9. Jules Vide

    Jules Vide Guest

    John Bean wrote:
    > >
    > >> A narrow depth of field focused on a near-field object, with the
    > >> background all fuzzy is a standard technique. To use it, you open up the
    > >> aperture and focus on the near-field object.

    > >
    > >Am I right or wrong in assuming you can't do this with a p&s camera,
    > >even if the camera has a setting called aperture priority?

    >
    > You're wrong. It's not as easy or flexible to do with
    > small-sensor cameras but if the point of focus is close
    > and/or a longer focal length is used it's perfectly
    > possible, and something I do quite often.


    I took the camera out of the box and tried to do this. I set the
    aperture for its lowest setting, then tried to focus on my exquisite
    Subaru. Whenever I touched the focus, even though I was in the "Av
    Priority" setting, the aperture setting changed. How else are you
    supposed to focus if not with the auto focus; and if the auto focus has
    dominance over the other customized settings, is this not just another
    way of saying the p&s can only autofocus?

    I'm not being rhetorical. I don't know any other way to focus outside
    of bodily getting the subject in focus by waltzing with myself, at
    which point my neighbors will have all the proof they need I've finally
    gone over the edge.
     
    Jules Vide, Jul 15, 2006
    #9
  10. Jules Vide

    John Bean Guest

    On 15 Jul 2006 14:21:37 -0700, "Jules Vide"
    <> wrote:

    >John Bean wrote:
    >> >
    >> >> A narrow depth of field focused on a near-field object, with the
    >> >> background all fuzzy is a standard technique. To use it, you open up the
    >> >> aperture and focus on the near-field object.
    >> >
    >> >Am I right or wrong in assuming you can't do this with a p&s camera,
    >> >even if the camera has a setting called aperture priority?

    >>
    >> You're wrong. It's not as easy or flexible to do with
    >> small-sensor cameras but if the point of focus is close
    >> and/or a longer focal length is used it's perfectly
    >> possible, and something I do quite often.

    >
    >I took the camera out of the box and tried to do this. I set the
    >aperture for its lowest setting, then tried to focus on my exquisite
    >Subaru. Whenever I touched the focus, even though I was in the "Av
    >Priority" setting, the aperture setting changed. How else are you
    >supposed to focus if not with the auto focus; and if the auto focus has
    >dominance over the other customized settings, is this not just another
    >way of saying the p&s can only autofocus?
    >
    >I'm not being rhetorical. I don't know any other way to focus outside
    >of bodily getting the subject in focus by waltzing with myself, at
    >which point my neighbors will have all the proof they need I've finally
    >gone over the edge.


    AF - autofocus - should have no effect whatsoever on the
    chosen aperture no matter what mode the camera is in unless
    you have selected some sort of auto-picture mode. The whole
    point of aperture-priority mode is that the aperture you set
    is fixed - in other words it takes priority over shutter
    speed.

    You're not confusing AF with zoom are you? If you "zoomed
    in" on the car the lens may have been forced to stop down;
    most P&S cameras don't have the same maximum aperture across
    the whole zoom range.

    --
    John Bean
     
    John Bean, Jul 15, 2006
    #10
  11. Jules Vide

    tomm42 Guest


    > > You're wrong. It's not as easy or flexible to do with
    > > small-sensor cameras but if the point of focus is close
    > > and/or a longer focal length is used it's perfectly
    > > possible, and something I do quite often.

    >
    > I took the camera out of the box and tried to do this. I set the
    > aperture for its lowest setting, then tried to focus on my exquisite
    > Subaru. Whenever I touched the focus, even though I was in the "Av
    > Priority" setting, the aperture setting changed. How else are you
    > supposed to focus if not with the auto focus; and if the auto focus has
    > dominance over the other customized settings, is this not just another
    > way of saying the p&s can only autofocus?
    >
    > I'm not being rhetorical. I don't know any other way to focus outside
    > of bodily getting the subject in focus by waltzing with myself, at
    > which point my neighbors will have all the proof they need I've finally
    > gone over the edge.


    Your asking some basic yet fair deep photo questions. You are talking
    about two variables that are interdependent on each other.
    Depth of field and exposure.
    Exposure is a relationship between, sensor sensitivity (ISO) shutter
    speed aperture, and ambient light. So for a given sensor ISO in a
    given lighting situation there is a a unique set of shutter speeds and
    apertures. The easiest one to explain is a sunny day at noon, your
    exposure in the sun will be 1/ISO at f16 so if you have an ISO of 125
    your exposure will be 1/125 @ f16, 1/250 @ f11, 1/500 @ f8, 1/1000 @
    f5.6. Vary the shutter speed you have to vary the aperture. What
    happened to you was the aperture was too large for the shutter speed of
    your camera. It also could be there is a preset that is set on your
    camera for groups or landscapes etc, check the menus and ditch that if
    you want to learn anything.
    Depth of field
    For every focal length there is a distance in front and in back of the
    focal point that will appear to be in sharp focus. So if you want a
    narrow depth of field in bright sunlight you better have 1/4000 or up
    on your camera cause if we go back to the earlier example the f stop
    for 1/4000 will be f2, a very wide aperture. But if you are
    photographing inside under artificial light I will be difficult to get
    alot of depth of field so say the exposure is 1/30 @f2.8 and you want
    to photograph a group, to even get f5.6 you are at 1/8 of a second,
    difficult to hand hold at that speed, a tripod, image stabilization or
    a flash (to get more light) is necessary.
    You should get a good photo book, be it film or digital based, the
    basics are the same. I also find a basis manual camera easier to get
    the concepts. Go find a second hand pentax K1000 and a 50mm lens and
    some ISO 100 film, find a pro lab to get contact sheets made and just
    shoot a couple of rolls using a match needle meter, you start to
    understand. If there was a cheap digital camera you could do the same
    thing with I'd say get that.


    Tom
     
    tomm42, Jul 15, 2006
    #11
  12. Jules Vide

    Paul Mitchum Guest

    Jules Vide <> wrote:

    > Paul Mitchum wrote:
    > >
    > > Actually, depth of field is the extent to which objects appear sharp in
    > > the print. But your definition is close enough for practical purposes.

    >
    > [SNIP HELPFUL CLARIFICATION]
    >
    > > A narrow depth of field focused on a near-field object, with the
    > > background all fuzzy is a standard technique. To use it, you open up the
    > > aperture and focus on the near-field object.

    >
    > Am I right or wrong in assuming you can't do this with a p&s camera, even
    > if the camera has a setting called aperture priority?


    You can do this with any lens that lets you set a small enough aperture.
    You'd have to use aperture priority if you wanted automatic metering.

    Some point-and-shoot cameras have a closeup or macro mode (usually shown
    on the mode selector as a little flower) you could try using instead.
    This works best for close, small objects (like, say... flowers), but try
    experimenting and see what else it'll do.
     
    Paul Mitchum, Jul 16, 2006
    #12
  13. Jules Vide

    Paul Mitchum Guest

    Paul Mitchum <0m> wrote:

    > Jules Vide <> wrote:
    >
    > > Paul Mitchum wrote:
    > > >
    > > > Actually, depth of field is the extent to which objects appear sharp in
    > > > the print. But your definition is close enough for practical purposes.

    > >
    > > [SNIP HELPFUL CLARIFICATION]
    > >
    > > > A narrow depth of field focused on a near-field object, with the
    > > > background all fuzzy is a standard technique. To use it, you open up the
    > > > aperture and focus on the near-field object.

    > >
    > > Am I right or wrong in assuming you can't do this with a p&s camera, even
    > > if the camera has a setting called aperture priority?

    >
    > You can do this with any lens that lets you set a small enough aperture.


    I did, of course, mean BIG enough aperture.

    > You'd have to use aperture priority if you wanted automatic metering.
    >
    > Some point-and-shoot cameras have a closeup or macro mode (usually shown
    > on the mode selector as a little flower) you could try using instead.
    > This works best for close, small objects (like, say... flowers), but try
    > experimenting and see what else it'll do.
     
    Paul Mitchum, Jul 16, 2006
    #13
  14. Jules Vide

    minnesotti Guest

    Jules Vide wrote:
    > ... tried to focus on my exquisite Subaru.


    Aha... you like your equipment... this is a characteristic of a "pixel
    peeper". If you are one, you need a camera better than Canon A620.
    Canon of cameras is a Toyota of cars. Get yourself a Panasonic LX1 or
    Ricoh GR-Digital.

    :)
     
    minnesotti, Jul 16, 2006
    #14
  15. Jules Vide

    jeremy Guest

    "Jules Vide" <> wrote in message

    >> A narrow depth of field focused on a near-field object, with the
    >> background all fuzzy is a standard technique. To use it, you open up the
    >> aperture and focus on the near-field object.

    >
    > Am I right or wrong in assuming you can't do this with a p&s camera,
    > even if the camera has a setting called aperture priority?
    >


    The degree to which you can shoot with shallow depth-of-field depends upon
    the lens you are using. Two specific factors are involved.

    1: Some lenses have wider maximum apertures than others. For example, my
    50mm f/1.4 lens will give me shallower depth-of-field when opened to maximum
    aperture than will my 35mm f/3.5, because the 50mm lens can open up wider.

    2: The focal length of the lens matters. Telephoto lenses have shallower
    depth of field than wide angle lenses. Wide angle lenses won't give you the
    shallow depth-of-field that you will get from telephoto lenses.

    So, if your objective it to blur the background, use a fast normal lens,
    opened to full aperture or close to full aperture, or use a telephoto lens.
    Don't use a wide angle lens and expect to have shallow depth-of-field.

    DIGITAL CAMERAS, with their typically-small sensor size, add another factor
    to the equation. Small sensor sizes result in MORE depth-of-field, all
    other things being equal. So you probably will not be able to get as
    shallow a depth-of-field on a digicam as you can on a film SLR with a fast
    normal lens.

    And many digicams do not allow the photographer to manually set the
    aperture. The cameras control aperture and shutter speed. If you own such
    a camera you will not be able to control the amount of depth-of-field at
    all.

    There are other digital cameras that have things like "portrait mode," where
    the camera will open up the lens to a wide aperture to achieve some degree
    of shallow depth-of-field. Check your camera manual to see if it has such a
    mode.

    Shallow depth-of-field is one of my favorite techniques to visually isolate
    the main subject from its surroundings, and I feel that I have the greatest
    degree of control by using it with one of my film cameras and 50mm f/1.4
    normal lenses. My digicam does not offer the ability to control aperture,
    so most of my shots naturally have a lot of depth-of-field. That is great
    for landscape shots, where I would want everything to be in sharp focus, but
    not good for times when I want shallow depth-of-field, such as for
    portraits.
     
    jeremy, Jul 16, 2006
    #15
  16. Jules Vide

    jeremy Guest

    "Jules Vide" <> wrote in message
    news:...
    > John Bean wrote:
    >> >
    >> >> A narrow depth of field focused on a near-field object, with the
    >> >> background all fuzzy is a standard technique. To use it, you open up
    >> >> the
    >> >> aperture and focus on the near-field object.
    >> >
    >> >Am I right or wrong in assuming you can't do this with a p&s camera,
    >> >even if the camera has a setting called aperture priority?

    >>
    >> You're wrong. It's not as easy or flexible to do with
    >> small-sensor cameras but if the point of focus is close
    >> and/or a longer focal length is used it's perfectly
    >> possible, and something I do quite often.

    >
    > I took the camera out of the box and tried to do this. I set the
    > aperture for its lowest setting, then tried to focus on my exquisite
    > Subaru. Whenever I touched the focus, even though I was in the "Av
    > Priority" setting, the aperture setting changed. How else are you
    > supposed to focus if not with the auto focus; and if the auto focus has
    > dominance over the other customized settings, is this not just another
    > way of saying the p&s can only autofocus?
    >
    > I'm not being rhetorical. I don't know any other way to focus outside
    > of bodily getting the subject in focus by waltzing with myself, at
    > which point my neighbors will have all the proof they need I've finally
    > gone over the edge.
    >


    Not to want to keep beating a dead horse, but if you had a simple, manual
    camera with a fast normal lens, you could achieve your objective with ease,
    any time you wanted.

    Automatic digital cameras, with their small sensors and factory-programmed
    exposure settings, make it difficult or impossible for the photographer to
    stay in control. Most people that use P&S cameras--film or
    digital--probably do not even know that there is such a thing as being able
    to control depth-of-field at all. Automation is a double-edged sword.

    Ideally one's camera should offer manual override. My film SLRs, the Pentax
    P3n and the P30t, both have automatic exposure but they allow me to manually
    set my shutter speed and aperture openings. If I open my aperture up full
    and that requires a shutter speed that is faster than my camera's maximum of
    1/1000, I just need to fit a neutral density filter onto the lens.
     
    jeremy, Jul 16, 2006
    #16
  17. Jules Vide

    Peter Irwin Guest

    jeremy <> wrote:
    >
    > 2: The focal length of the lens matters. Telephoto lenses have shallower
    > depth of field than wide angle lenses. Wide angle lenses won't give you the
    > shallow depth-of-field that you will get from telephoto lenses.


    That's true for the case where you are shooting at the same
    istance for each lens. If you are shooting for the same
    reproduction ratio, the DOF will be similar for different
    focal length lenses. So if you shoot from 1 meter away with
    a 35mm lens and 5 meters away with a 175mm lens so that the
    image size is the same in both cases, you will get similar
    DOF at the same aperture.

    Peter.
    --
     
    Peter Irwin, Jul 16, 2006
    #17
  18. Jules Vide

    Paul Mitchum Guest

    Peter Irwin <> wrote:

    > jeremy <> wrote:
    > >
    > > 2: The focal length of the lens matters. Telephoto lenses have shallower
    > > depth of field than wide angle lenses. Wide angle lenses won't give you the
    > > shallow depth-of-field that you will get from telephoto lenses.

    >
    > That's true for the case where you are shooting at the same
    > istance for each lens. If you are shooting for the same
    > reproduction ratio, the DOF will be similar for different
    > focal length lenses. So if you shoot from 1 meter away with
    > a 35mm lens and 5 meters away with a 175mm lens so that the
    > image size is the same in both cases, you will get similar
    > DOF at the same aperture.


    This is illustrated here: <http://www.dofmaster.com/dofjs.html>

    Plug in the numbers you want.
     
    Paul Mitchum, Jul 16, 2006
    #18
  19. Jules Vide

    Jules Vide Guest

    John Bean wrote:
    > On 15 Jul 2006 14:21:37 -0700, "Jules Vide"
    > <> wrote:
    > >
    > >I took the camera out of the box and tried to do this. I set the
    > >aperture for its lowest setting, then tried to focus on my exquisite
    > >Subaru. Whenever I touched the focus, even though I was in the "Av
    > >Priority" setting, the aperture setting changed. How else are you
    > >supposed to focus if not with the auto focus; and if the auto focus has
    > >dominance over the other customized settings, is this not just another
    > >way of saying the p&s can only autofocus?

    >
    > You're not confusing AF with zoom are you? If you "zoomed
    > in" on the car the lens may have been forced to stop down;
    > most P&S cameras don't have the same maximum aperture across
    > the whole zoom range.


    Obviously I am. As I posted on another thread, I just realized that I
    don't know how to--and my user's manual doesn't tell me how to--focus
    without the zoom.
     
    Jules Vide, Jul 16, 2006
    #19
  20. Jules Vide

    Jules Vide Guest

    tomm42 wrote:
    >
    > Go find a second hand pentax K1000 and a 50mm lens and
    > some ISO 100 film, find a pro lab to get contact sheets made and just
    > shoot a couple of rolls using a match needle meter, you start to
    > understand. If there was a cheap digital camera you could do the same
    > thing with I'd say get that.


    Tom, you are a Usenet "find." I'm going to try to do exactly this but
    with an old Nikon my "art school" Dad, now deceased, left us, among
    Rollies and other cameras. I need a specific manual that will first
    tell me which control is which, and then my July free-time project is
    going to be what you suggest. I've had enough!
     
    Jules Vide, Jul 16, 2006
    #20
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