Fuji or Canon Movies?

Discussion in 'Fuji' started by Philip S, Nov 26, 2005.

  1. Philip S

    Philip S Guest

    Which movie mode is the best? The Fuji f10/11 or Canon A610/620. Fuji seems
    to get nearly twice as much on a card so is it compressed much more. Also
    Fujis may be a lot less grainy. Id like to see some
    comparison of the two makes somewhere especially in low light
     
    Philip S, Nov 26, 2005
    #1
    1. Advertisements

  2. Philip S

    SleeperMan Guest

    comparison would be good, however you should know that more compression
    means less quality. Canon usually has motion JPEG which is most quality one.
    It's similar like if you compare video cameras with cassette or those with
    HDD or DVD recording---> reviews say hat ones with HDD and DVD have visible
    compression artifacts and distortion.
     
    SleeperMan, Nov 26, 2005
    #2
    1. Advertisements

  3. Philip S

    timeOday Guest

    That's an overgeneralization. Some compression algorithms are just
    better (smaller size AND better quality) than others. Even two
    implementations of the same codec will vary.

    My Canon S80 burns about 2 megabytes per second, which is ridiculous.
    That's 16 megabits per second! For comparison, DVDs are a third of
    that. My best guess is that the camera is doing a computationally cheap
    compression to save money and energy.

    I don't have an answer to the question of which is better, but the great
    thing about the Finepix F10 is the low sensor noise. Compressing from a
    clean (low noise) source is very important to getting small, good
    looking results from compression.
     
    timeOday, Nov 28, 2005
    #3
  4. The current standard for consumer-level standard-resolution video is
    miniDV, which is 25 megabits/sec. It uses a compression scheme that is
    close to motion JPEG. The Canon digicams generally produce motion-JPEG
    video directly, but 16 Mb/sec is already considerably more compressed
    than DV, so you should expect some quality loss. Still, motion JPEG can
    be easily edited (each frame is independent).
    DVDs use MPEG compression, which compresses away similarities between
    successive frames and encodes only differences. It gets better
    compression, but (a) editing MPEG content involves an additional
    decompression step, and (b) it can't handle large differences between
    adjacent frames. The various video recorders that encode directly to
    MPEG-2 in real time (various video digitizers, DVD camcorders, DVD-R
    recorders) are all regarded as producing inferior video compared to DV.

    In addition, the MPEG content you see on good DVDs was likely compressed
    by a multi-pass compressor that doesn't operate in real time. A video
    camera has to compress in real time.

    Personally, I'd rather have the higher-quality video with lower
    compression encoded as DV or motion JPEG, rather than realtime
    compressed MPEG-2.

    Dave
     
    Dave Martindale, Nov 29, 2005
    #4
  5. Philip S

    timeOday Guest

    For a given bitrate, a codec with interframe compression should have a
    big quality advantage over one without. Fewer bits wasted on redundant
    information means more for fine detail. If that advantage isn't
    realized by current consumer devices, perhaps it's because they're
    cutting the bitrate *too* much. Or maybe it's just too computationally
    expensive to do it right on a device powered by such a small battery.

    Anyways, my complaint with Canon's video encoding certainly isn't with
    the quality; I don't see any compression artifacts. In fact I see a lot
    of sensor noise that I wish was smoothed away. But the larger problem
    is simply the amount of memory required. A 1 Gig card only lasts 8
    minutes. I'm not saying other current products offer a better
    space/quality tradeoff, but if not I think there's a lot of improvement
    to look forward to.

    For one thing I don't understand is why the digital zoom doesn't work
    better. Since it's only keeping a 640x480 frame, and full-res images
    are 3200x2400, a good 5x digital zoom should be possible.

    Second, the video is too noisy. There are enough pixels on the sensor
    to use a 5x5 rectangle of pixels for every single output pixel at
    640x480 (if not using digital zoom), but I suspect they're not using
    them. (Admittedly I don't know that to be the case).
     
    timeOday, Nov 29, 2005
    #5
  6. In principle, you're right. However, it's worth noting that in the
    worst case (successive frames very different from each other),
    interframe compression gets you nothing, and thus the maximum allowed
    bit rate out of the interframe codec needs to be equal to that of the
    intraframe-only codec in order to handle that worst case with similar
    quality.

    In practice, devices that use MPEG-2 "DVD compatible" encoding tend to
    aim for an average bit rate of something like 4-6 Mbits/s, with an
    absolute maximum of around 9 Mb/s, and that just isn't enough to do as
    well at DV codecs that have 25 Mb/s to work with. So in the worst case,
    DV is much better off.

    One particularly weird thing is that the camcorders that record to hard
    disk never seem to have a DV-like codec available. They are all
    MPEG-only. Yet a DV codec shouldn't be any challenge for hardware
    capable of doing MPEG, and the disk should be able to handle the data
    rate easily (it's only 3 MBytes/sec).
    Provided the camera is actually reading the whole sensor at 30 FPS and
    downsampling. But perhaps it is reading only every Nth scanline, or
    binning pixels, for faster read speed.
    Could be.

    Dave
     
    Dave Martindale, Nov 30, 2005
    #6
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.