A&P is it just me or does f-stop on p&s simply not functional??

Discussion in 'Lifestyle' started by multiplexor, Aug 18, 2005.

  1. multiplexor

    multiplexor Intellectual

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    I'm assuming this is why i read that dslr's differ big time here...

    but with my a85 for example, i can set the f to 2.8 and take a pic and my subject is clear and so is the background... it's only in macro shots that the f-stop actually works as it should... lol

    i'm assuming from the pics seen, that if i purchased a 300d, the F2.8 setting would actually blur the background/foreground/ giving me proper dof....

    stupid P&s.. :-/
     
  2. SpiderOnTheFloor

    SpiderOnTheFloor New Member

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    yeah, get a 300d
     
  3. tenplanescrashing

    tenplanescrashing Active Member

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    i've always wondered the same thing...
     
  4. hash browns

    hash browns lolcathlon champion OT Supporter

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    get closer to the subject

    depth of field is related to the focal length, distance to subject, distance of subject to background and aperture size ....

    it becomes more apparent with macros because you are... closer to your subject
     
  5. Jcolman

    Jcolman OT Supporter

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    This is correct. But to help clarify why your point and shoot is always sharp at f/2.8....it's most likely because of the focal length of the lens. Point and shoot cameras typically rely on a medium wide lens.
    A wide angle lens will always render everything in the pic in focus, regardless of aperature setting, unless you're focusing extremely close to the lens.
     
  6. multiplexor

    multiplexor Intellectual

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    So the use of the f-stop on p&s digi's is essentially for macro mode or to help darken or lighten a pic your taking in non macro mode.

    must purchase a 300d :-/ damnit
     
  7. hash browns

    hash browns lolcathlon champion OT Supporter

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    Don't think you have to do this ...


    Consider zooming your lens in to the maximum focal length ---> the longer the focal length, the less depth of field

    Get closer to your subject ---> less depth of field

    Put your subject further away from the background, and choose a cleaner backgroudn ---> less depth of field



    If you want to shoot on the wide end, get very close to your subject -- Wide angles have a different sense of subject-background separate that makes backgrounds feel much further away than they are from your subject. You can also use this to make your backgrounds seem out of focus.


    Too many people that get their first SLR shoot their lenses wide open -- at their largest aperture -- because they think it is what's best to get the totally out of focus effect.
     
  8. CRC

    CRC New Member

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    Yeah, and lenses are less sharp wide open. Plus the fact you only have like 2mm of focus in your pictures. I learned this the hard way
     
  9. multiplexor

    multiplexor Intellectual

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    just to br sure i understand :big grin:

    by this:

    If you want to shoot on the wide end, get very close to your subject -- Wide angles have a different sense of subject-background separate that makes backgrounds feel much further away than they are from your subject. You can also use this to make your backgrounds seem out of focus.

    you mean, basically get closer to the subject, make sure your zoomed out, keep the f2.8 setting, but it's possible the pic might not have the full body in the picture (that type of close) I think i understand what you mean, just trying to visualize the shot... :)

    Also the other thing you're stating, is that i shouldn't try to use tooo much zoom because the more i zoom in, on P&S digi's, the image becomes less sharp?

    Thanks for the tips at the same time :big grin:
     
  10. hash browns

    hash browns lolcathlon champion OT Supporter

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    No, just get closer. The closer your subject is to you, and i mean very close with a wide angle or telephoto, the more out-of-focus the background will seem.

    With wide angles you can shoot with a semi-large aperture, f/2.8 and f/4, or even smaller like f/5.6 -- and if you are very close, it will have a different way of separating the subject from the background than a telephoto will.

    "Zooming in" will increase the focal length, and that will reduce the depth of field.
     
  11. multiplexor

    multiplexor Intellectual

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    coolies, i'll attempt this next time i go out :big grin:

    thanks!
     

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