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Thread: Point to focus?

  1. #1

    Default Point to focus?

    I would like to seek some clarifications from the masters here.

    Understand that the sharpest focus will be right at the centre of the view finder. So when taking portrait, where should we focus? 1. Place subject in the centre of the view finder and take a wider view, then crop later or 2. place the subject at the point where we want i.e. rule of third?

  2. #2
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    Default Re: Point to focus?

    - All focus points can be as sharp if focused correctly.
    - If you are using the focus and recompose method to get your thirds while using large aperture lens, you may not get the focus correct due to shifting of focal pane which may cause your subject sit outside your DOF.

    What I'll do, just use the focus point nearest to your subject. Decent cameras at least have 9 AF points to choose from and of which those off center points are relatively near the one third intersection points.
    Too many great equipments but too little quality photos. [My Flickr] | [My Blog]

  3. #3

    Default Re: Point to focus?

    learn to change AF points.

  4. #4
    Moderator Octarine's Avatar
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    Default Re: Point to focus?

    Quote Originally Posted by Golagislow View Post
    Understand that the sharpest focus will be right at the centre of the view finder.
    Are you talking about best AF sensor or center sharpness of the lens?
    EOS

  5. #5

    Default Re: Point to focus?

    Quote Originally Posted by Golagislow View Post
    Understand that the sharpest focus will be right at the centre of the view finder.
    You understand wrongly.
    Alpha

  6. #6

    Default Re: Point to focus?

    Quote Originally Posted by Golagislow View Post
    I would like to seek some clarifications from the masters here.

    Understand that the sharpest focus will be right at the centre of the view finder. So when taking portrait, where should we focus? 1. Place subject in the centre of the view finder and take a wider view, then crop later or 2. place the subject at the point where we want i.e. rule of third?
    Your questions seem a bit confusing! Let's see if this is what you are looking for.
    when using AF then it generally locks focus at the centre. Switch to selective focus if you wanted the focus point to lock into a desire area, you need to shift the focus point around by pressing a up/down/left/right dial.

  7. #7

    Default Re: Point to focus?

    Quote Originally Posted by flame angel View Post
    Your questions seem a bit confusing! Let's see if this is what you are looking for.
    when using AF then it generally locks focus at the centre. Switch to selective focus if you wanted the focus point to lock into a desire area, you need to shift the focus point around by pressing a up/down/left/right dial.
    depends on which brand you're using.

    when using Wide AF (multi AF, landscape AF, whatever), the camera picks the most prominent subject/area that's most likely contrasty enough to focus on. NOT always selecting objects in the center

  8. #8

    Default Re: Point to focus?

    Quote Originally Posted by Octarine View Post
    Are you talking about best AF sensor or center sharpness of the lens?
    Sorry for not been clear in my question. Yes, I'm referring to the sharpness of the lens.

  9. #9
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    Default Re: Point to focus?

    Quote Originally Posted by Golagislow View Post
    Sorry for not been clear in my question. Yes, I'm referring to the sharpness of the lens.
    Then the biggest question is how big is your final output? Even kit lens at wide open aperture can produce sharp output with abit of sharpening during post processing.

    If you are only uploading as Facebook pic, you will have other things to worry about besides sharpness.


    Then, If you really want really sharp output from all lenses, stop down the aperture by about 1-2 stop and you should get tack sharp images.
    Too many great equipments but too little quality photos. [My Flickr] | [My Blog]

  10. #10
    Member Mythmaker's Avatar
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    Default Re: Point to focus?

    If you crop, you lose subject isolation than when you frame it directly. And your image will not be as sharp as when you select the closest AF point at ROT because:

    1) You lose megapixel from cropping; you lose details and sharpness.
    2) You lose subject isolation from cropping, which means it's theoretically possible to stop down and get the same DOF with almost identical framing. When you stop down, the lens become sharper. So the corner AF point, though not as sharp as the center initially, will end up as sharp or even sharper than the center AF with the same resulting image.

    Unless your len's corners is really, really very bad and you are using the edge AF, otherwise it's alright to even use wide open on small print selecting the closest AF point.
    Last edited by Mythmaker; 23rd July 2013 at 10:47 AM.

  11. #11

    Default Re: Point to focus?

    Quote Originally Posted by Golagislow View Post
    I would like to seek some clarifications from the masters here.

    Understand that the sharpest focus will be right at the centre of the view finder. So when taking portrait, where should we focus? 1. Place subject in the centre of the view finder and take a wider view, then crop later or 2. place the subject at the point where we want i.e. rule of third?
    Sharpest focus can be anywhere as long as its the most accurate focus. Sharpest part of the lens is usually the center. These two are different things.

    The most accurate AUTO focus points (I think this is what you are talking about), is usually the center.

    When taking portrait, it depends on situation and shooter. As a photographer specializing in portraits, I had done all sorts from focus and recompose, manual focus, adjusting focus points, live view, full auto reliance, to focusing via for DOF distance scale, to recropping in post. It depends on the availability of time, patience and eyesight, both your's and your camera's. Sometimes even your camera can't see.

    No right way, only best way for the situation.
    Last edited by sjackal; 23rd July 2013 at 10:52 AM.
    WTB Manfrotto RC4 L Bracket

  12. #12

    Default Re: Point to focus?

    Now I have some idea, thanks for all the masters sharing..

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