Question on depth of field

Discussion in 'Digital Photography' started by Bob, Jun 14, 2004.

  1. Bob

    Bob Guest

    I'm trying to photograph flower beds, and I'm having trouble getting everything
    in focus. I've tried going to F22 and ISO 800 but I'd rather use a lower ISO...

    But how does the mm of the lens affect this? If I set my zoom lens to either
    100mm or 300mm, which would cover the deepest area? (assuming I step back to
    frame the same picture.) I don't mean the deepest percentage - I just mean a 5
    foot flower bed!

    Would I get more depth if I use a 24mm lens and get in closer?

    Note - I do like the fact the background is out of focus - but I do want more
    range...

    Thanks for any help.
    Bob, Jun 14, 2004
    #1
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  2. Bob

    Jeff Durham Guest

    I am new at this so someone else step in here if I have this wrong. A wide
    angle lens and/or higher f numbers (smaller opening) will help to get your
    entire image into focus. A wide angle lens at the same fstop as a telephoto
    lens will have more of the picture in focus. Also, try to get the item in
    front in focus rather than the item at the back. That way, the entire
    picture should be in focus.

    Jeff


    "Bob" <> wrote in message
    news:...
    >
    > I'm trying to photograph flower beds, and I'm having trouble getting

    everything
    > in focus. I've tried going to F22 and ISO 800 but I'd rather use a lower

    ISO...
    >
    > But how does the mm of the lens affect this? If I set my zoom lens to

    either
    > 100mm or 300mm, which would cover the deepest area? (assuming I step back

    to
    > frame the same picture.) I don't mean the deepest percentage - I just

    mean a 5
    > foot flower bed!
    >
    > Would I get more depth if I use a 24mm lens and get in closer?
    >
    > Note - I do like the fact the background is out of focus - but I do want

    more
    > range...
    >
    > Thanks for any help.
    >
    Jeff Durham, Jun 14, 2004
    #2
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  3. Bob

    Tony Spadaro Guest

    The wider the lens the more dof, however, if the widest you have is 100mm
    that is not going to be a whole lot of DOF to work with. A 50 or a 24 would
    do the job better
    --
    http://www.chapelhillnoir.com
    home of The Camera-ist's Manifesto
    The Improved Links Pages are at
    http://www.chapelhillnoir.com/links/mlinks00.html
    A sample chapter from my novel "Haight-Ashbury" is at
    http://www.chapelhillnoir.com/writ/hait/hatitl.html
    "Bob" <> wrote in message
    news:...
    >
    > I'm trying to photograph flower beds, and I'm having trouble getting

    everything
    > in focus. I've tried going to F22 and ISO 800 but I'd rather use a lower

    ISO...
    >
    > But how does the mm of the lens affect this? If I set my zoom lens to

    either
    > 100mm or 300mm, which would cover the deepest area? (assuming I step back

    to
    > frame the same picture.) I don't mean the deepest percentage - I just

    mean a 5
    > foot flower bed!
    >
    > Would I get more depth if I use a 24mm lens and get in closer?
    >
    > Note - I do like the fact the background is out of focus - but I do want

    more
    > range...
    >
    > Thanks for any help.
    >
    Tony Spadaro, Jun 14, 2004
    #3
  4. Bob

    Guest

    In message <iN7zc.92309$>,
    "Jeff Durham" <> wrote:

    >A wide angle lens at the same fstop as a telephoto
    >lens will have more of the picture in focus.


    Not if they are the same size in the image; DOF will be the same for
    500mm from 20 feet away, and 50mm from 2 feet away, with the same
    f-stop.
    --

    <>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
    John P Sheehy <>
    ><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
    , Jun 14, 2004
    #4
  5. Bob

    Guest

    In message <Lq8zc.26148$>,
    "Tony Spadaro" <> wrote:

    >The wider the lens the more dof,


    .... at the same f-stop, from the same distance.
    --

    <>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
    John P Sheehy <>
    ><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
    , Jun 14, 2004
    #5
  6. Bob

    Bob Guest

    On Mon, 14 Jun 2004 02:59:28 GMT, wrote:

    >In message <iN7zc.92309$>,
    >"Jeff Durham" <> wrote:
    >
    >>A wide angle lens at the same fstop as a telephoto
    >>lens will have more of the picture in focus.

    >
    >Not if they are the same size in the image; DOF will be the same for
    >500mm from 20 feet away, and 50mm from 2 feet away, with the same
    >f-stop.


    So you are saying that if I want to frame a certain view, it doesn't matter what
    the MM of the lens is? If I have a subject of say 4 feet in depth, and I pick
    different lenses and walk back and forth to get the same crop, I will always
    have the same depth of field?

    How do I go about getting a deeper field in this situation? Am I limited to F
    stops?

    Or put it this way - if I use a 28-300mm zoom, and pick a view of 6 specific
    flowers, meaning I walk back as the mm goes up, the depth of field will always
    be the same? I guess I could try this for myself!
    Bob, Jun 14, 2004
    #6
  7. Bob

    Ron Risman Guest

    Hi Bob,

    When trying to control depth-of-field there are three variables that can be
    adjusted, depending on your camera. Two of them you have already played
    around with (aperture and ISO). The third setting you can adjust is the
    Shutter speed (Tv).

    When you shoot at F22 you will lose a lot of light which is why you bumped
    up the ISO to 800, however in order to get a wide depth of field you will
    need to stay at a smaller aperture such as F20 or F22 or somewhere in that
    range depending on the subject, distance, etc. Here's what I'd recommend.

    Using a tripod.
    1) Put the camera in full manual mode if you can.
    2) Set the camera to F22
    3) Set the camera to ISO 100 or 200
    4) Lower the shutter speed until you achieve the brightness desired.

    If it's a sunny day you probably won't have to slow it down too much. Also,
    keep in mind that any movement of the flowers (from wind) will show up as
    blue if the shutter speed is too slow. Trial and error will help get you
    the right results.

    Here are some images to show depth of field examples:
    http://www.cameratown.com/guides/assets/aperture_comparison.jpg
    http://www.cameratown.com/guides/assets/aperture_compare.jpg

    I hope this information helps.


    Ron Risman, Webmaster
    http://www.cameratown.com




    "Bob" <> wrote in message
    news:...
    >
    > I'm trying to photograph flower beds, and I'm having trouble getting

    everything
    > in focus. I've tried going to F22 and ISO 800 but I'd rather use a lower

    ISO...
    >
    > But how does the mm of the lens affect this? If I set my zoom lens to

    either
    > 100mm or 300mm, which would cover the deepest area? (assuming I step back

    to
    > frame the same picture.) I don't mean the deepest percentage - I just

    mean a 5
    > foot flower bed!
    >
    > Would I get more depth if I use a 24mm lens and get in closer?
    >
    > Note - I do like the fact the background is out of focus - but I do want

    more
    > range...
    >
    > Thanks for any help.
    >
    Ron Risman, Jun 14, 2004
    #7
  8. Bob wrote:
    > I'm trying to photograph flower beds, and I'm having trouble getting
    > everything in focus. I've tried going to F22 and ISO 800 but I'd
    > rather use a lower ISO...


    It is difficult to get a everything in focus when doing close up work.

    >
    > But how does the mm of the lens affect this? If I set my zoom lens to
    > either 100mm or 300mm, which would cover the deepest area? (assuming
    > I step back to frame the same picture.) I don't mean the deepest
    > percentage - I just mean a 5 foot flower bed!


    The depth of focus is the same, no matter what the zoom is set for or
    what lens you use as long as the image size on the sensor is the same size
    and the same aperture is used. The perspective may change however.

    >
    > Would I get more depth if I use a 24mm lens and get in closer?


    No.

    >
    > Note - I do like the fact the background is out of focus - but I do
    > want more range...
    >
    > Thanks for any help.


    I suggest smaller apertures. You may use longer exposures or more
    light.

    I suggest that part of the problem may be camera movement, even the best
    of us may have a problem there. Use a tripod. Very important in close up
    work.

    Consider changing the angle so you need less depth of focus.

    Consider that subject movement (wind) sometimes looks like a focus
    problem.

    One last step. Give up and get a camera with full swing and tilt
    capability. They can handle most every focus problem.

    --
    Joseph E. Meehan

    26 + 6 = 1 It's Irish Math
    Joseph Meehan, Jun 14, 2004
    #8
  9. Bob

    bagal Guest

    Hmm - I am surprised a pro nhasn't picked up the old 1/3 and 2/3 rule

    das B

    "Bob" <> wrote in message
    news:...
    >
    > I'm trying to photograph flower beds, and I'm having trouble getting

    everything
    > in focus. I've tried going to F22 and ISO 800 but I'd rather use a lower

    ISO...
    >
    > But how does the mm of the lens affect this? If I set my zoom lens to

    either
    > 100mm or 300mm, which would cover the deepest area? (assuming I step back

    to
    > frame the same picture.) I don't mean the deepest percentage - I just

    mean a 5
    > foot flower bed!
    >
    > Would I get more depth if I use a 24mm lens and get in closer?
    >
    > Note - I do like the fact the background is out of focus - but I do want

    more
    > range...
    >
    > Thanks for any help.
    >
    bagal, Jun 14, 2004
    #9
  10. Bob

    Bob Guest

    On Mon, 14 Jun 2004 17:12:35 +0100, "bagal" <> wrote:

    >Hmm - I am surprised a pro nhasn't picked up the old 1/3 and 2/3 rule
    >
    >das B
    >


    Can you clue me it to that?
    Bob, Jun 15, 2004
    #10
  11. Bob

    Bob Guest

    On Mon, 14 Jun 2004 07:07:41 GMT, "Ron Risman" <> wrote:

    >Hi Bob,
    >
    >When trying to control depth-of-field there are three variables that can be
    >adjusted, depending on your camera. Two of them you have already played
    >around with (aperture and ISO). The third setting you can adjust is the
    >Shutter speed (Tv).
    >
    >When you shoot at F22 you will lose a lot of light which is why you bumped
    >up the ISO to 800, however in order to get a wide depth of field you will
    >need to stay at a smaller aperture such as F20 or F22 or somewhere in that
    >range depending on the subject, distance, etc. Here's what I'd recommend.
    >
    >Using a tripod.
    >1) Put the camera in full manual mode if you can.
    >2) Set the camera to F22
    >3) Set the camera to ISO 100 or 200
    >4) Lower the shutter speed until you achieve the brightness desired.
    >
    >If it's a sunny day you probably won't have to slow it down too much. Also,
    >keep in mind that any movement of the flowers (from wind) will show up as
    >blue if the shutter speed is too slow. Trial and error will help get you
    >the right results.
    >
    >Here are some images to show depth of field examples:
    >http://www.cameratown.com/guides/assets/aperture_comparison.jpg
    >http://www.cameratown.com/guides/assets/aperture_compare.jpg
    >
    >I hope this information helps.
    >


    ya thanks!
    Bob, Jun 15, 2004
    #11
  12. Bob

    Guest

    In message <>,
    Bob <> wrote:

    >On Mon, 14 Jun 2004 02:59:28 GMT, wrote:


    >>In message <iN7zc.92309$>,
    >>"Jeff Durham" <> wrote:


    >>>A wide angle lens at the same fstop as a telephoto
    >>>lens will have more of the picture in focus.


    >>Not if they are the same size in the image; DOF will be the same for
    >>500mm from 20 feet away, and 50mm from 2 feet away, with the same
    >>f-stop.


    >So you are saying that if I want to frame a certain view, it doesn't matter what
    >the MM of the lens is?


    Well, it does matter, because camera shake will be worse with the longer
    focal lengths, but as far as DOF is concerned

    >If I have a subject of say 4 feet in depth, and I pick
    >different lenses and walk back and forth to get the same crop, I will always
    >have the same depth of field?


    Yep, if the f-stop is the same.

    >How do I go about getting a deeper field in this situation? Am I limited to F
    >stops?


    All other things being equal, you need a higher f-stop (smaller
    aperture)

    >Or put it this way - if I use a 28-300mm zoom, and pick a view of 6 specific
    >flowers, meaning I walk back as the mm goes up, the depth of field will always
    >be the same? I guess I could try this for myself!


    With the same aperture, yes. The trade-off is geometrical distortion vs
    camera shake, when choosing the focal length (f-stop being equal) a
    shorter focal length is more likely to have geometric distortion, and a
    long focal length is more likely to recsult in blur from camera motion.
    --

    <>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
    John P Sheehy <>
    ><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
    , Jun 15, 2004
    #12
  13. Bob

    Paul J Gans Guest

    Bob <> wrote:

    >I'm trying to photograph flower beds, and I'm having trouble getting everything
    >in focus. I've tried going to F22 and ISO 800 but I'd rather use a lower ISO...


    >But how does the mm of the lens affect this? If I set my zoom lens to either
    >100mm or 300mm, which would cover the deepest area? (assuming I step back to
    >frame the same picture.) I don't mean the deepest percentage - I just mean a 5
    >foot flower bed!


    >Would I get more depth if I use a 24mm lens and get in closer?


    >Note - I do like the fact the background is out of focus - but I do want more
    >range...


    >Thanks for any help.


    As many people will tell you, a shorter lens will have more
    depth of field, everything else staying the same.

    Thus a 300mm lens will have a much smaller depth of field
    than a 50mm lens.

    So you need to chose the lens focal length to suit what you
    are doing -- the subject depth, the distance to the subject,
    the presence of anything you want to throw out of focus,
    etc.

    ----- Paul J. Gans
    Paul J Gans, Jun 15, 2004
    #13
  14. Bob

    Bob Guest

    On Mon, 14 Jun 2004 23:51:32 GMT, wrote:

    >In message <>,
    >Bob <> wrote:
    >
    >>On Mon, 14 Jun 2004 02:59:28 GMT, wrote:

    >
    >>>In message <iN7zc.92309$>,
    >>>"Jeff Durham" <> wrote:

    >
    >>>>A wide angle lens at the same fstop as a telephoto
    >>>>lens will have more of the picture in focus.

    >
    >>>Not if they are the same size in the image; DOF will be the same for
    >>>500mm from 20 feet away, and 50mm from 2 feet away, with the same
    >>>f-stop.

    >
    >>So you are saying that if I want to frame a certain view, it doesn't matter what
    >>the MM of the lens is?

    >
    >Well, it does matter, because camera shake will be worse with the longer
    >focal lengths, but as far as DOF is concerned
    >
    >>If I have a subject of say 4 feet in depth, and I pick
    >>different lenses and walk back and forth to get the same crop, I will always
    >>have the same depth of field?

    >
    >Yep, if the f-stop is the same.
    >
    >>How do I go about getting a deeper field in this situation? Am I limited to F
    >>stops?

    >
    >All other things being equal, you need a higher f-stop (smaller
    >aperture)
    >
    >>Or put it this way - if I use a 28-300mm zoom, and pick a view of 6 specific
    >>flowers, meaning I walk back as the mm goes up, the depth of field will always
    >>be the same? I guess I could try this for myself!

    >
    >With the same aperture, yes. The trade-off is geometrical distortion vs
    >camera shake, when choosing the focal length (f-stop being equal) a
    >shorter focal length is more likely to have geometric distortion, and a
    >long focal length is more likely to recsult in blur from camera motion.



    OK thanks for the info!! I remember that I used to look at my zoom setting to
    make sure I was around 50mm to make sure I wasn't getting too much distortion -
    at least when I could frame the shot that way... I imagine that it doesn't
    matter that I've gone to digital and have a 'crop factor' of 1.5.... 50mm is
    still 50mm even if the camera makes it look like 75.
    Bob, Jun 15, 2004
    #14
  15. Bob

    Bob Guest

    On Tue, 15 Jun 2004 03:01:49 +0000 (UTC), Paul J Gans <> wrote:

    >Bob <> wrote:
    >
    >>I'm trying to photograph flower beds, and I'm having trouble getting everything
    >>in focus. I've tried going to F22 and ISO 800 but I'd rather use a lower ISO...

    >
    >>But how does the mm of the lens affect this? If I set my zoom lens to either
    >>100mm or 300mm, which would cover the deepest area? (assuming I step back to
    >>frame the same picture.) I don't mean the deepest percentage - I just mean a 5
    >>foot flower bed!

    >
    >>Would I get more depth if I use a 24mm lens and get in closer?

    >
    >>Note - I do like the fact the background is out of focus - but I do want more
    >>range...

    >
    >>Thanks for any help.

    >
    >As many people will tell you, a shorter lens will have more
    >depth of field, everything else staying the same.


    actually, people have told me that only the F stop changes the depth of field...
    I guess you'll have to explain that too me!! If you would be so kind that is, I
    would appreciate it!

    >Thus a 300mm lens will have a much smaller depth of field
    >than a 50mm lens.
    >
    >So you need to chose the lens focal length to suit what you
    >are doing -- the subject depth, the distance to the subject,
    >the presence of anything you want to throw out of focus,
    >etc.


    are there some easy rules for this?

    I know that long lenses compress things, bring in the background, lose light,
    and tend to shake; medium lenses are good for portraits; and short lenses
    distort things (especially noses) but are good for selling real estate... :)

    > ----- Paul J. Gans
    Bob, Jun 15, 2004
    #15
  16. "Bob" <> wrote in message
    news:...
    SNIP
    > actually, people have told me that only the F stop changes the depth of

    field...

    Correct, if the magnification factor remains the same, which requires
    different distances for different focal lengths.

    Bart
    Bart van der Wolf, Jun 15, 2004
    #16
  17. Bob

    Guest

    In message <caloqt$ni3$>,
    Paul J Gans <> wrote:

    >As many people will tell you, a shorter lens will have more
    >depth of field, everything else staying the same.


    .... but everything else can't be the same. If you are at the same
    distance, then the magnification changes with different focal lengths.
    --

    <>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
    John P Sheehy <>
    ><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
    , Jun 15, 2004
    #17
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