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Thread: can't auto forcus on white blank object..

  1. #1

    Default can't auto forcus on white blank object..

    dunno y....using 18-55mm lens and i'm like 1-2m away from the object.

  2. #2

    Default Re: can't auto forcus on white blank object..

    minimum focusing length. if you want nearer then need to use manual focus.
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  3. #3

    Default Re: can't auto forcus on white blank object..

    lol...using minimum 18mm focal length already....can't focus on a white wall, white book 4m away.

  4. #4
    Senior Member zac08's Avatar
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    Default Re: can't auto forcus on white blank object..

    YOU CAN'T FOCUS on a white BLANK subject.

    The AF module requires CONTRAST. Duh.... Make sure there is enough contrast. If you don't believe, get a white piece of paper and put it in front of you. You'll never be able to lock onto it.

    Then draw a cross on the paper, see how easily your camera then locks onto the cross. Always understand you gear first. READ MORE.
    Michael Lim
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  5. #5

    Default Re: can't auto forcus on white blank object..

    lol no wonder...so how can i set custom white balance using white paper method if i can't focus? manual focus?

    Quote Originally Posted by zac08 View Post
    YOU CAN'T FOCUS on a white BLANK subject.

    The AF module requires CONTRAST. Duh.... Make sure there is enough contrast. If you don't believe, get a white piece of paper and put it in front of you. You'll never be able to lock onto it.

    Then draw a cross on the paper, see how easily your camera then locks onto the cross. Always understand you gear first. READ MORE.
    Last edited by baggiolee; 14th February 2009 at 03:42 AM.

  6. #6

    Default Re: can't auto forcus on white blank object..

    arrgg i got it...lol. need to go menu to set so dun need focus.

  7. #7
    Senior Member zac08's Avatar
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    Default Re: can't auto forcus on white blank object..

    Quote Originally Posted by baggiolee View Post
    lol no wonder...so how can i set custom white balance using white paper method if i can't focus? manual focus?
    Do it manually.... the custom white balance does not need the subject to be in focus. As long as they white portion fills the screen, it's more than good enough.
    Michael Lim
    My Flickr Site

  8. #8
    Moderator catchlights's Avatar
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    Default Re: can't auto forcus on white blank object..

    when doing custom WB, just press the Focusing Lock will do, the surface don't need to in focus, don't need to switch to manual focusing too.
    Shoot to Live, Live to Shoot
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  9. #9

    Default Re: can't auto forcus on white blank object..

    thx guys...i'm such a noob...more readings for me lol.

  10. #10

    Default Re: can't auto forcus on white blank object..

    Might be a bit easier if you shoot RAW?

    Edit: This is an alternative to setting custom white balance. Does not address the issue of AF.
    Last edited by ahbian; 15th February 2009 at 09:31 AM.

  11. #11
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    Default Re: can't auto forcus on white blank object..

    anyway the post have been answered correctly. good job. just remember there is "minimal focusing distance" for any lense and it is not always the same..

    and dont post garbage. thanks.

  12. #12
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    Default Re: can't auto forcus on white blank object..

    Quote Originally Posted by ahbian View Post
    Might be a bit easier if you shoot RAW?
    what in the world got to do with this ****?

  13. #13

    Default Re: can't auto forcus on white blank object..

    Quote Originally Posted by ahbian View Post
    Might be a bit easier if you shoot RAW?
    Quote Originally Posted by ronaldjace View Post
    what in the world got to do with this ****?
    The reason why TS is trying to focus on a white paper is to do a custom white balance. My suggestion is that he can adjust the white balance easier in post processing if he shoots in RAW.

    It is not a cure all or absolute replacement for custom white balance, but it is convenient.

    Your post regarding not posting rubbish, is it directed to me?
    Last edited by ahbian; 15th February 2009 at 07:38 AM.

  14. #14
    Moderator catchlights's Avatar
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    Default Re: can't auto forcus on white blank object..

    Quote Originally Posted by ahbian View Post
    Might be a bit easier if you shoot RAW?
    doing custom WB is get setting right in camera. and also cutting down post processing workflow.

    Not all situation are possible to shoot RAW.

    for an instant, if I need to give my customs the jpg right after the photo session, shooting RAW and without custom WB, what kind of benefit and conventient can I get?
    Shoot to Live, Live to Shoot
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  15. #15

    Default Re: can't auto forcus on white blank object..

    Quote Originally Posted by catchlights View Post
    doing custom WB is get setting right in camera. and also cutting down post processing workflow.

    Not all situation are possible to shoot RAW.

    for an instant, if I need to give my customs the jpg right after the photo session, shooting RAW and without custom WB, what kind of benefit and conventient can I get?
    If we are using Jpeg, then yes, i agree that we need to get it as close to right as in camera.

    Post processing wise, for me, its is just two steps, which i can accept may be two steps too many for others.

    My suggestion is to open the TS to other possibilities besides struggling with custom white balance.

    Your senario of giving jpeg to a customer immediately is valid, but it is not what I need to encounter as I'm a hobbist, hence the different perspective.

  16. #16

    Default Re: can't auto forcus on white blank object..

    Quote Originally Posted by zac08 View Post
    YOU CAN'T FOCUS on a white BLANK subject.

    The AF module requires CONTRAST. Duh.... Make sure there is enough contrast. If you don't believe, get a white piece of paper and put it in front of you. You'll never be able to lock onto it.

    Then draw a cross on the paper, see how easily your camera then locks onto the cross. Always understand you gear first. READ MORE.
    yeah right, the AF cannot focus in all white neither all black surface, so you have to search any contrast or doing manual focus.

    Quote Originally Posted by ahbian View Post
    Might be a bit easier if you shoot RAW?
    how come? hehehe...

  17. #17

    Default Re: can't auto forcus on white blank object..

    Quote Originally Posted by marboed View Post
    yeah right, the AF cannot focus in all white neither all black surface, so you have to search any contrast or doing manual focus.



    how come? hehehe...
    Quote Originally Posted by ahbian View Post
    The reason why TS is trying to focus on a white paper is to do a custom white balance. My suggestion is that he can adjust the white balance easier in post processing if he shoots in RAW.

    It is not a cure all or absolute replacement for custom white balance, but it is convenient.

    Your post regarding not posting rubbish, is it directed to me?
    I understand that I should be more specific in my postings next time. Shooting in RAW helps in the setting of white balance (which was the also one of the intentions of the TS) , not the focusing of the blank object.

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