which aspect ratio?

Discussion in 'Video Cameras' started by melianbriggs, Jan 31, 2007.

  1. melianbriggs

    melianbriggs Guest

    Hello everyone! The last contact I had with this group regarded asking
    for some guidance around dedicated home video software. I have now
    taken the plunge and opted for Adobe Premier Elements 3.0. I have
    installed this and launched for the first time.

    On the settings tab on the first window that opens, I am asked to
    select between two ratios (one being widescren). I think the other is
    4.3 aspect ratio. My question is which setting? I normally use a
    widescreen TV. what I am not sure about is the capture ratio of my
    camcorder. I posess a Sony Handycam DCR/HC35E. I have looked at the
    manual briefly and it appears that I can select either option. I
    suspect that this depends whether I use the Easy Handycam mode or
    not.

    I have not had much opportunity recently to start shooting and editing
    and I am generally at the complete novice stage at the moment! I am
    looking forward to learning about this new found hobby and trust that
    with you guys behind me - things will be a bit less daunting!

    Any help will be gratefuly received.

    melianbriggs
     
    melianbriggs, Jan 31, 2007
    #1
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  2. melianbriggs

    G Hardy Guest

    Try both, and see which you like best. Whatever you do, maintain the same
    aspect ratio through shooting, editing, burning and viewing.

    If you shoot 4:3, you'll get the best detail, as that's the native aspect
    ratio of your camera. You'll get black sidebars when viewing, though (unless
    your TV stretches the 4:3 footage to file a 16:9 screen).

    If you shoot 16:9, or if you crop your 4:3 footage to 16:9 during the edit,
    you'll lose detail.

    The *only* way to get full detail for both aspect ratios without changing
    cameras is to use an anamorphic lens.
     
    G Hardy, Jan 31, 2007
    #2
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  3. .... or a camera with a "true" 16:9 mode, ie it's got all the pixels
    needed to capture the 16:9 image, and isn't just stretching a lesser set
    of pixels to do it. SOME little, recent Sony camcorders do this; many
    more serious ones do; but not all!
     
    David Pearson, Feb 2, 2007
    #3
  4. melianbriggs

    G Hardy Guest

    in message
    I did say "full detail for both aspect ratios".

    If you have a 16:9 CCD, then your 4:3 footage will crop the left/right of
    the image, losing quality.
     
    G Hardy, Feb 2, 2007
    #4
  5. melianbriggs

    Tony Morgan Guest

    I'm not sure if that's the case.

    Consider the 'norm' of 720 x 576 (achieving a 4:3 ratio).
    By my calculations that works out at 720 x 576 px = 414,720 px.

    It varies from camcorder to camcorder, but (for example) my DCR-TRV80E
    comes with 2.1 Mpx CCD. This obviously gives a huge overhead when only
    414,720 px is used. Even very low-end camcorders come with 800 Kpx.

    If we extrapolate to a 16:9 widescreen image, we're then talking
    1024 x 576 to achieve the same resolution., i.e. 1024 x 576 = 589,824
    px. Even with our low-end camcorder with an 800 Kpx CCD then there's
    still an appreciable overhead.

    Obviously in practice the camcorder's DSP uses all the available CCD
    pixels by interpolation to give the best possible resolution. But the
    bottom line is that there are more than sufficient CCD pixels to resolve
    both 16:9 and 4:3 display ratios - so why should there be a drop in
    resolution.

    In practice with my 80E, shooting in WS (16:9) and in 4:3 show no
    discernible drop in resolution - at least not to my tired old eyes :)

    Having said all that, all the MiniDV camcorder specs/reviews that I've
    seen seem to quote between 510 and 520 lines resolution - both for 4:3
    and for 16:9. So the limiting factor seems to be the media (i.e.
    MiniDV). And since the line resolution is in the horizontal axis, it
    seems to suggest that whether 16:9 or 4:3, there's no difference.

    If my logic is flawed perhaps you can point out just where it falls
    down?

    But to the OP, the answer has already been given - if he shoots at 4:3,
    then he should edit and produce his video at 4:3 - if he shoots at 16:9
    then he should edit and produce his video at 16:9. And the 'banding' L/R
    or top/bottom will depend on the aspect ratio of his TV screen (or his
    PC display).
     
    Tony Morgan, Feb 2, 2007
    #5
  6. melianbriggs

    melianbriggs Guest

    Hello again. I wondered if anyone may posess a Sony Handycam DCRHC35E
    and if so is there a way of switching 16.9 aspect ratio on and off? It
    mentions something in the user guide regarding this but I found it a
    bit confusing! What is "letterbox" and basicaly if I want to view in
    widescreen (my tv is widescreen) and edit my footage/create DVDs in
    widescreen (using adobe premier elements 3.0) having first selected
    this option, what setting should I use initially on my camcorder -
    assuming this "setting" exists?

    regards melianbriggs
     
    melianbriggs, Feb 7, 2007
    #6
  7. melianbriggs

    G Hardy Guest

    There's a very slight flaw in your maths, because you're mixing square and
    nonsquare pixels. Extrapolating 720x576 at 4:3 to a 16:9 equivalent gives
    960x576.

    For DV or DVD cameras, the number of pixels is a red herring. If you have
    more than 720x576, they will be sampled down. Ideally, as you state, the
    sampling should take place after the crop (although the cynic in me wonders
    if this happens, because it's cheaper* to crop after the sampling).

    The statement I made is very much subjective - a bit like saying that a DVD
    encoded at 7mbps will be better quality than the same footage at 6.5mbps. A
    high pixel count CCD on a video camera will most likely be a 4:3 aspect
    ratio. Assuming that's true, and assuming square pixels, a 2.1MP CCD equates
    to 1673x1255px. For 4:3 footage that works out at 5 CCD pixel samples per
    DVD pixel output. To get the best 16:9 footage out of the same CCD, you'd
    only be using 1673x941px - which when translated to DVD resolution works out
    at 3.8 CCD pixel samples per DVD pixel output.

    The same is true if you start with a 16:9 ratio CCD, but it's the 4:3 mode
    that "loses" quality. The figures work out differently if you use the actual
    resolution of the CCD rather than my "worked back" figures that are based on
    2.1MP, they are also different if your CCD has nonsquare pixels, but the
    principle is the same.

    So that's the basis of saying that the only way to get equal quality between
    4:3 and 16:9 footage recorded using the same CCD is to use bendy glass on
    the front of the camera, not electronics within it... That way you're using
    _all_ of the CCD (whatever its dimensions) to record _both_ aspects.


    * I'm working from a basis of assumption & ignorance, but the maths holds
    true. For example, I've assumed (as you have) that the camera companies will
    attempt to use all of the CCD output to its best. I reckon it's cheaper to
    sample a big CCD down to 720x576 and then crop the resulting video to
    widescreen because the routines already exist in older cameras to crop
    footage of that size.
     
    G Hardy, Feb 9, 2007
    #7
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