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Thread: how to isolate subject from background?

  1. #1
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    Default how to isolate subject from background?

    I am a new member here. Using powershot A540, so just wanna how to isolate a subject from the background. Use aperture setting or using focus lock???
    can help?

  2. #2

    Default Re: how to isolate subject from background?

    try using the widest aperture - f2.6 and use the telezoom from 100 -140mm and focus on your subject

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    Default Re: how to isolate subject from background?

    Quote Originally Posted by snipershot View Post
    I am a new member here. Using powershot A540, so just wanna how to isolate a subject from the background. Use aperture setting or using focus lock???
    can help?
    use the longest focal length and widest aperture... and try to frame your subject so that it is further away from the BG.

  4. #4

    Default Re: how to isolate subject from background?

    just to add on... go as close to subject as possible.
    but, its pretty hard to get decent isolation out of pns cameras
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    Default Re: how to isolate subject from background?

    you can also use colour

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    Default Re: how to isolate subject from background?

    flash+macro (or use the shortest focusing distance)+wideopen aperture = background bokeh smooth smooth...
    Logging Off. "You have 2,631 messages stored, of a total 400 allowed." don't PM me.

  7. #7
    Senior Member velasco's Avatar
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    Default Re: how to isolate subject from background?

    but i believe this powershot cam donot produce that distinct BOKEH.
    My A520 can't after tons of tryouts. They can slightly so i tend to digitally bokeh-rize them

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    Default Re: how to isolate subject from background?

    Basically, its very difficult to produce the distinctive "bokeh" effects on P&S. You might stand a better chance with a prosumer though it is almost equally hard.

    Though not really revelant, these are some photos for my projects which I did not too long ago, taken with my Panasonic LZ1. No adjustments (except for resize) to the photos have been done. Not too sure if you wanted to achieve similar effects.


    01




    02




    03


  9. #9
    Senior Member velasco's Avatar
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    Default Re: how to isolate subject from background?

    this is what i get with my A520




  10. #10

    Default Re: how to isolate subject from background?

    Understanding Depth of Field (DOF, do a google search or read it up on some prominent photography website) would go a long way towards knowing how to isolate the subject from the background. The trick is to have a shallow DOF just enough to have the subject in focus but throws the background out of focus. DOF is related to focal length, distance to subject, aperture and image sensor size.

    DOF is inversely proportional to actual focal length used. Point and Shoot cameras like the A540 have a very small sensor and very short actual focal lengths (e.g. actual focal length is only 5-20+mm for 35-105mm on the 35mm format equivalent) and so having a shallow DOF is much more difficult than a DSLR/SLR. For such short focal length and small sensor size, a shallow DOF is more achievable only when the subject distance is very near (i.e. close up or macro where the focal length used is very much relatively nearer to the subject distance than when the subject is much further away).

    Aperture size is also inversely related to DOF or in other words, aperture F numbers are directly proportional to DOF. Use a large aperture (i.e. small F numbers such as between F/2.8-F/4) to have a shallower DOF.

    Colour and bightness contrast also contribute to the isolation.

    Read up on Complementary Colours and Harmonizing Colours. Understanding the colour spectrum will help you in knowing which colours are complementary etc.

    The subject much brighter than the background would also make the subject stand out against the background. Try to avoid bright background as bright areas tend to attract attention away from the subject. Also certain colours (e.g. yellow and light green) are "brighter" than others.
    Last edited by Clockunder; 3rd November 2006 at 11:56 PM.

  11. #11
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    Default Re: how to isolate subject from background?

    Quote Originally Posted by Clockunder View Post
    Understanding Depth of Field (DOF, do a google search or read it up on some prominent photography website) would go a long way towards knowing how to isolate the subject to the background. The trick is to have a shallow DOF just enought to have the subject in focus but throws the background out of focus. DOF is related to focal length, distance to subject, aperture and image sensor size.

    DOF is inversely proportional to actual focal length used. Point and Shoot cameras like the A540 have a very small sensor and very short actual focal lengths (e.g. actual focal length is only 5-20+mm for 35-105mm on the 35mm format equivalent) and so having a shallow DOF is much more difficult than a DSLR/SLR. For such short focal length and small sensor size, a shallow DOF is more achievable only when the subject distance is very near (i.e. close up or macro where the focal length used is very much relatively nearer to the subject distance than when the subject is much further away).

    Colour and bightness contrast also contribute to the isolation.

    Read up on Complementary Colours and Harmonizing Colours. Understanding the colour spectrum will help you in knowing which colours are complementary etc.

    The subject much brighter than the background would also make the subject stand out against the background. Try to avoid bright background as bright areas tend to attract attention away from the subject. Also certain colours (e.g. yellow and light green) are "brighter" than others.
    I would suggest you read up on it too and understand it better. You can ask here but the answers you get will not be extensive enough.

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    Default Re: how to isolate subject from background?

    ok. I will try to understand. haha. Thanks for the advices!

  13. #13
    Senior Member zoossh's Avatar
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    Default Re: how to isolate subject from background?

    various way in the wider sense of isolation (making the subject stands out from the background)

    1. blurring the background with bokeh (narrow depth of field)
    2. simple background
    3. contrasting colors
    4. contrasting tone (lighted versus dark background)
    5. lines that lead to the subject
    6. contrasting pattern

  14. #14

    Default Re: how to isolate subject from background?

    Quote Originally Posted by zoossh View Post
    various way in the wider sense of isolation (making the subject stands out from the background)

    1. blurring the background with bokeh (narrow depth of field)
    2. simple background
    3. contrasting colors
    4. contrasting tone (lighted versus dark background)
    5. lines that lead to the subject
    6. contrasting pattern

    7. use of lights
    8. use photoshop.. burn burn burn burn.. or blur blur blur blur..
    9. cropping and pespective

  15. #15

    Default Re: how to isolate subject from background?

    wow velasco ... this is an incredible shot ... how did you do that?!? i understand the DOF thing but how did you get that colour and the gradient of light (from darkest to light)???

    rgds
    another newbie ...
    Last edited by hokokhua; 8th November 2006 at 09:21 AM.

  16. #16
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    Default Re: how to isolate subject from background?

    try going near the subj and choose a background that is faaaaaar behind. say subj is about 1-1.5 meter away and there is nothing behind him until about 5-10 metre. higher chance of a background blur.
    Last edited by surge; 8th November 2006 at 10:22 PM.

  17. #17

    Default Re: how to isolate subject from background?

    It's hard to do a good bokeh with PnS or Prosumer camera even at widest aperature size or longest focal length... But doing it like macro (closer to subject) will work...
    I am NOT a PROfessional photographer and photography is NOT my hobby

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