"Motion Blur": AVCHD issue or operator error?

Discussion in 'Digital Video' started by Courtaj, Jul 23, 2008.

  1. Courtaj macrumors 6502a

    Courtaj

    Joined:
    Jul 3, 2008
    Location:
    Edinburgh, U.K.
    #1
    Attached are two frame grabs from a 10-second shot recorded in 1080i on a little Panasonic SD5 AVCHD camera - replete (an understatement!) with motion blur artefacts.

    The second jpeg was grabbed after deinterlacing this single shot with iMovie HD. It tidies up the weirdness a little, but the shot is clearly still unacceptable.

    Is this an AVCHD issue (I know it's not an ideal shot in many ways, but I wouldn't have expected this much in the way of "blur") or operator error? TBH I can't now remember what shutter speed I was using, but it was a reasonably sunny day, and I think it would have been 1/100 or 1/125 at least.

    Your thoughts welcome.

    Thanks,
    Andrew.

    EDIT: I should add that the original .mts file was converted with Voltaic, preserving framerate and size, on an iBook G4. Naturally, it played back fine in the camera's LCD. It's not a one-off: I have a number of shots that resemble this, shot in a wide variety of circumstances, all converted with Voltaic and all unusable. The jpegs below are screen grabs from an LCD which I presume is progressive. But the deinterlaced shot is still rubbish.
     

    Attached Files:

  2. bobbleheadbob macrumors 6502a

    bobbleheadbob

    Joined:
    Feb 6, 2007
    Location:
    Massachusetts
    #2
    I've noticed more blurring with the Canon HF10 AVCHD that I got recently than I experienced with my Sony HD miniDV camcorder. Or when just grabbing video with a P&S digital camera, for that matter. I don't think I'm doing anything differently. :confused:

    Any thoughts or tips would be appreciated.
     
  3. evil_santa macrumors 6502a

    evil_santa

    Joined:
    Sep 23, 2003
    Location:
    London, England
    #3
    this is to do with interlaced video getting converted, I have experienced this with fast moving action that look fine in standard pal, then getting downsized to a 400x300 mpeg.

    It seem to happen is going from a interlaced clip to a progressive clip, ie losing the 2 fields going to a single frame.

    Both grabs show the results of different de interlacing , I expect the problem is with Voltaic.

    are you able to digitize directly in to fcp or imovie from the camera with out conversion?
     
  4. Courtaj thread starter macrumors 6502a

    Courtaj

    Joined:
    Jul 3, 2008
    Location:
    Edinburgh, U.K.
    #4
    Thanks for that.

    I'm going to be buying a Mac Mini as soon as (or is that "if"?) Apple announces an upgrade. iMovie HD on my G4 iBook won't touch AVCHD, hence my using Voltaic to convert to .mov.

    I'm going to try importing the .mts file into iMovie at an Apple retailer to see if it makes any difference. iMovie 08 will convert AVCHD to AIC, but if it does that without this disastrous "effect" then I have to say, I wonder what Voltaic is good for. I didn't realise it was converting from interlaced to progressive. I did mean to deinterlace the second time though (outputting from iMovie HD as a deinterlaced QT movie, which is where the second grab is taken from).

    Voltaic certainly seems to have some issues - at least in my experience - with deciding where one frame ends and another begins, or with matching the interlacing to the new progressive frame, or something. The result is useless video. Needless to say I won't be "activating" the free Voltaic trial.

    Andrew.
     
  5. CMD is me macrumors 6502

    Joined:
    Dec 7, 2006
    #5
    How did the video look straight into your TV? I shot with a couple Sony AVCHD cameras at 1080i and they looked very clean. No blurring. Didn't import them though... maybe I'm not helping.
     
  6. Courtaj thread starter macrumors 6502a

    Courtaj

    Joined:
    Jul 3, 2008
    Location:
    Edinburgh, U.K.
    #6
    Problem sorted (I think).

    This morning I tried importing the same clip into iMovie 08, and then exporting as a Quicktime movie. Still a little blurring going on in the iMovie preview window (can live with that) but completely tidied up after import.

    Ah. That's more like it.

    Moral of the story: give Voltaic a miss if you have an aging iBook G4 with minimal space left on the harddrive. I'm not sure which of these factors (processor, harddrive) is the critical one here, but something made it all add up to a garbled mess.

    Thanks chaps,
    Andrew.
     

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