Green screen problemer

En tråd i 'Spesial-effekter, rekvisita, sminke og kostymer' startet av Stian`s HD videoer, 29 Jun 2011.

  1. Stian`s HD videoer

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    Hei :eek:

    har et Canon hf100

    fant en tråd på nettet på engelsk om en som har samme problem som meg.

    http://www.youtube.com/watch?v=e_SPHYQAsWY

    se videoen min for og se feilen, se nøye på 0:10 hva som skjer. Dette er ikke skygge, men virker som kameraet går i automatisk exposure eller noe , Jeg har kameraet på TV mode, ( shutter prio AE ) jeg legger ved tråden under her på engelsk så dere kan se også.



    The problem I'm having is the brightness of the greenscreen background changes (as viewed on the camera display or in my movie) as I move in and out of the frame, making it impossible to key if I'm moving around.

    For example, I start the video focused on just the greenscreen. Then as I walk into the frame, the greenscreen background gets brighter. As I move out of the frame, the greenscreen background gets darker. It's so obvious as I'm watching this happen on the cameras display.

    I don't think my body is reflecting light back into the screen, it seems like the camcorder is doing some adjusting to the background brightness. If I set the manual exposure on the camera to -2 (or more) and make the whole scene darker, it works, the greenscreen stays the same brightness as I move in and out of the frame.

    What's going on here? Why is the camera adjusting the background brightness depending on if I'm in the frame or not.

    Thanks.


    OGSÅ FIKK HAN SVAR TILBAKE , les under

    Is the camera in manual mode? If in automatic exposure, it will automatically adjust video gain/exposure based on the average brightness. As you walk into the frame, the overall brightness level that the camera sees changes and the auto gain compensates, which will affect the brightness of your background as well. If you are wearing bright or light colored clothing, the camera will see the average brightness increase and decrease it's gain. This will decrease the background brightness as well. If your image is darker than the background, then the opposite happens and the gain increases which, in turn, increases the brightness of the background as a side effect.

    Try setting the camera in manual exposure mode and adjust for the desired gain with you in the frame. The background will stay more consistent.

    MEN JEG SKJØNNER IKKE, det er jo ikke noe manuell mode i kameraet , bare disse settingene , P, TV, AV , CINE MODE . Men hva gjør jeg da? hvis han sier at dette skal fungere?


    Håper på hjelp.. fryktelig irriterende opplegg altså. :mad:
     
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  2. Alex DeLarge

    Alex DeLarge Lt. Jr. Grade

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