Several Questions

Discussion in 'Digital Video' started by kepardue, May 13, 2009.

  1. kepardue macrumors 6502

    Joined:
    Oct 28, 2006
    #1
    So I've been copying my movies over from a tape-based HD camcorder for the last couple of years. I've got roughly 25 1-hour tapes from the past 4 years, all of which I have copied into iMovie at full HD quality. And, patience to be commended here, I have run stabilization analysis on all of it.

    Reading this month's MacWorld, however, has led me into several questions. It's apparent that tape-based camcorders really are going the way of the dodo, and the Macworld article plays up on this heavily. In fact, it only lists 3 tape-based camcorders vs. 12 Flash or HDD based solutions. Fair enough, the last time I really researched this was when iMovie didn't support AVCHD video and the quality difference (not to mention ability to have archive copies) was astounding. Now I guess things have changed. My questions are:

    1 - Given that Apple pushes the non-tape-based camcorders (via the argument that most new camcorders favor USB2 over Firewire and that Firewire is otherwise unnecessary on new Macs), I now read that iMovie's stabilization doesn't work well with non-tape-based camcorders because of the type of sensor that they use. Isn't this contradictory? Are there any Flash-based camcorders that stabilization does work with?

    2 - Why would Apple introduce the stabilization feature if it can only be used on a rapidly-obsolete format?

    3 - Can we expect an update in a future version that will bring stabilization support to video shot with CMOS sensors?

    4 - The article states that HDV vs. AVCHD is quality vs. convenience. Is the quality difference big enough to be concerned about?

    5 - It also says that iMovie imports in 720p vs. 1080i. Can iMovie not work with 1080p? Given that progressive seems to be far superior to interlaced, would it be better to work in 720p? Maybe this is something that happens on the camcorder's end.

    6 - The article states that iMovie must re-encode the video from AVCHD into Apple's Intermediary Codec. Is any quality lost in this transfer?

    7 - And Last - The article says that a conversion between AVCHD and Apple's Intermediary Codec takes a 150MB file and converts it to a 1.1GB file. This is astounding. Why can't iMovie work directly with the original AVCHD files? Would this be something that we might see in a future version? And, is it common practice to use "Archive All" the original contents of the camcorder, so as to preserve the original footage for that magical day when we can work with a 150MB file instead?
     
  2. LethalWolfe macrumors G3

    LethalWolfe

    Joined:
    Jan 11, 2002
    Location:
    Los Angeles
    #2
    Do you have a link to the Macworld article? iMovie doesn't work w/AVCHD or HDV natively. Both formats get converted into AIC and nobody knows what Apple will or will not do w/future updates.


    Lethal
     
  3. kepardue thread starter macrumors 6502

    Joined:
    Oct 28, 2006
    #3
  4. kepardue thread starter macrumors 6502

    Joined:
    Oct 28, 2006
    #4
    Reading a little bit more about AIC... it seems to support either 720p or 1080i. When video is imported and the choice is presented for Large or Full, is this 720p and 1080i, respectively?
     
  5. arjen92 macrumors 65816

    arjen92

    Joined:
    Sep 9, 2008
    Location:
    Below sea level
    #5
    1 - Given that Apple pushes the non-tape-based camcorders (via the argument that most new camcorders favor USB2 over Firewire and that Firewire is otherwise unnecessary on new Macs), I now read that iMovie's stabilization doesn't work well with non-tape-based camcorders because of the type of sensor that they use. Isn't this contradictory? Are there any Flash-based camcorders that stabilization does work with?

    There are 3 ways you can stabilize. 1) is optical, which is for every camera that supports it. 2) is digital build in the camera (option 1) and 2) needs to be activate while recording0 and the third option 3) is digital on your computer. On your computer account (for me, I'm using final cut pro) for every format. So I won't see why this wouldn't be for iMovie, as I think the feature is imported from fcp.

    2 - Why would Apple introduce the stabilization feature if it can only be used on a rapidly-obsolete format?

    I think it works on several format's (at least in fcp). So I think it will definetely work on HDV, and ofcourse AIC.

    3 - Can we expect an update in a future version that will bring stabilization support to video shot with CMOS sensors?

    Whether your camera is CMOS or 3CCD doesn't matter. It's about the format. Whether I (that's me) film with cmos or 3ccd on DV, it's imported as DV and not as "the cmos format" or "3cdd format".

    4 - The article states that HDV vs. AVCHD is quality vs. convenience. Is the quality difference big enough to be concerned about?

    Don't know. Believe it's the same, although AVCHD truly is compressed. And I would say HDV is more convenient although you have to import it.

    5 - It also says that iMovie imports in 720p vs. 1080i. Can iMovie not work with 1080p? Given that progressive seems to be far superior to interlaced, would it be better to work in 720p? Maybe this is something that happens on the camcorder's end.

    I believe 1080i has twice the frames.

    6 - The article states that iMovie must re-encode the video from AVCHD into Apple's Intermediary Codec. Is any quality lost in this transfer?

    I don't think so. But wouldn't know.

    7 - And Last - The article says that a conversion between AVCHD and Apple's Intermediary Codec takes a 150MB file and converts it to a 1.1GB file. This is astounding. Why can't iMovie work directly with the original AVCHD files? Would this be something that we might see in a future version? And, is it common practice to use "Archive All" the original contents of the camcorder, so as to preserve the original footage for that magical day when we can work with a 150MB file instead?

    AVCHD is really really compressed. It takes a lot power. So less compressed (HDV) means less power. This makes editing less long.
     

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