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Thread: Grey Card

  1. #1

    Default Grey Card

    hI, may i know how to use a grey card to shoot ? is there a procedure or something like tat ??? and how to get a 18% grey card ???

  2. #2
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    juz position ur grey card to where ur subject is and meter off it. u can get them at cathay photos

  3. #3

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    hmm ... izzit shoot with the exposure read from the grey card? wat effect does it have on the result ?

  4. #4
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    to calibrate the white balance. you will get more accurate white balance. another alternative you can order through online shopping. Cost me S$10 including shipping. Right to your doorstep. kodak one

  5. #5

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    BTW, one very interesting thing about looking up on grey cards on the internet. 'Grey' is also spelt as 'Gray' in the US.

  6. #6

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    the valued exposure from the grey card.
    will be 18% grey, or middle gray which will place those in the same tone to be in the same zone.
    Zone 5

    so what will you expose for then.

    then what use will a grey be of.

  7. #7
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    Originally posted by 007
    to calibrate the white balance. you will get more accurate white balance. another alternative you can order through online shopping. Cost me S$10 including shipping. Right to your doorstep. kodak one
    It is more for exposure metering than WB setting, even though it can be used that way.

    Camera metering relies on the reflected light from the subject, so the calculation has to make certain assumptions about the reflectivity of the subject. Most center weighted metering systems will assume that the subject is 18% reflective. While this is generally representative of the actual scene, in tricky lighting and subject combinations where the reflectivity is not 18%, the camera metering will not be accurate.

    For example, snow reflects more than 18%. If center weighted metering is used on snow, it will turn out underexposed. The reverse applies when metering of dark objects. The camera will tend to overexpose.

    So the grey card is used to work hand in hand with the camera's metering as it reflects 18% of the light that falls onto it. To use it, place it near the subject so that it is receiveing the same lighting as the subject. Fill the frame of the camera with the grey card and take an exposure reading. Note the aperture and shutter setting and set it manually to what the camera suggests. Then the actual picture can be taken with that exposure setting (after removing the grey card from the scene ).

    I believe matrx metering should do a much better job than center weighted, so using a grey card is too much a hassle for me.

    The more expensive (more than 100X more expensive) method is to use an incident light meter.

    - Roy
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

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    I could have mixed up the 18% part in my post above.

    18% grey should mean 72% reflective. 18% reflectivity sounds too low to me.

    Any one can confirm?

    - Roy
    As complexity rises, precise statements lose meaning and meaningful statements lose precision.

  9. #9

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    (0_0") ~ wah .... aku dun understand ....

  10. #10
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    Originally posted by roygoh
    I could have mixed up the 18% part in my post above.

    18% grey should mean 72% reflective. 18% reflectivity sounds too low to me.

    Any one can confirm?

    - Roy
    That's a point to ponder....

    I think it's really 18% reflectivity. 72% sounds too bright.

    Is reflectivity logarithmic by the way?

    Regards
    CK

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