Video mode is more zoomed in?

Discussion in 'iPhone' started by MacScho, Jul 11, 2010.

  1. MacScho macrumors member

    Joined:
    Apr 9, 2008
    #1
    Why is this?

    I just noticed when you flick the switch from camera mode to video mode. In video mode the lens zooms in slightly.

    Has everyone got this?
     
  2. Eric8199 macrumors 6502a

    Joined:
    Feb 27, 2009
    #2
    The picture is zoomed in, the video is not. It's widescreen. Double tap the screen and it will zoom out.
     
  3. Spaced Cowboy macrumors newbie

    Joined:
    Apr 9, 2010
    #3
    Yeah, you're right. It's about 28mm wide (equivalent) in photo mode, and probably around 35mm (equivalent) in video mode.
     
  4. Daveoc64 macrumors 601

    Joined:
    Jan 16, 2008
    Location:
    Bristol, UK
    #4
    Yes.

    The video camera shoots at a fixed resolution of 720p (1280 * 720). The camera has a much higher resolution than this, so the phone basically cuts the sides off when you shoot video.

    That results in the image looking "zoomed in".
     
  5. SnowLeopard2008 macrumors 604

    SnowLeopard2008

    Joined:
    Jul 4, 2008
    Location:
    Silicon Valley
    #5
    Not exactly right. The display is 3:2 aspect ratio while 720P video is 16:10 aspect ratio. You can zoom the viewfinder out to display the black bars on the top/bottom or zoom in. This does not affect the video you record, just how the viewfinder works.
     
  6. Amnesia87 macrumors 6502

    Joined:
    Jun 19, 2010
    #6
    720P is 16:9

    And you are wrong and he is right.

    Instead of recording the video using the entire sensor and then scaling the video down, they are using sensor crop and only using the center of the censor.

    This produces the appearance of zoom. Much in the same way an APS-C SLR looks more zoomed in than an SLR with a Full Frame sensor.

    It's due to a change of viewing angle.

    It's referred to as Crop Factor.

    You can read about it here:

    http://en.wikipedia.org/wiki/Crop_factor

    You can find some examples here:

    http://www.dpreview.com/learn/?/Glossary/Optical/Focal_Length_Multiplier_01.htm

    http://www.nicolasgenette.com/Labo/Articles/CropFactor/index_us.php/

    http://www.millhouse.nl/digitalcropfactorframe.html

    http://www.minasi.com/photos/dslrmag/



    In conclusion you are completely wrong and what you see on the screen when you tap to zoom out and see the bars, is exactly what you are recording, and is in fact "zoomed"

    Some people are hoping apple will update the way the sensor works to use 4x the area on the sensor, and then some sort of pixel averaging down-scaling technique to use more of the sensor and thus more light without a huge bump in processing power. But at the moment there is no way around this crop.
     

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