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  • ADVC-110 picture quality and IRE issues

    I am capturing old VHS and VHS-C tapes in order to convert them to DVD. I am in the US and am using all NTSC hardware. I am using the following equipment:

    JVC SR-MV45 Professional line S-VHS/DVD combo VCR
    Canopus ADVC-110
    PC

    I am also using an old school Sharp VC-A542 VCR for testing.

    Here is my problem... I went through the hassle of capturing about 70 hours of old movies to my computer with the JVC and Canopus units. I set the Canopus unit to 7.5 IRE and captured away. The problem is that after burning my first movie I noticed the video was very dark. A digital waveform monitor in my NLE confirmed my suspicions. The captured video was about 16 digital units darker than the source.

    After exhaustive testing I have determined that the drop in luma is caused by the Canopus ADVC110 unit especially when I enable the JVC's TBC feature. If I attach the JVC directly to my TV the luma values are fine, however if I place the ADVC unit between the VCR and TV the luma values drop.

    I have made absolutely sure my IRE switch is set to 7.5IRE.

    I also noticed there is significant distortion (jittery, wavy output) when the Canopus is in the chain.

    I have attached a link to captured video clips at the bottom of this post along with a description of what the clips contain.

    Here are my questions...

    1. Is the drop in luma values normal for this Canopus unit?

    2. Should I expect to see conversion artifacts (jittery, wavy) when playing video through the Canopus unit?

    3. Why would the use of a TBC affect luma but only when the Canopus is involved?

    Thanks in advance!

    Clips

    Color bars clip
    Description: Color bars output in 7.5IRE mode by the Canopus ADVC110.
    Recorded: Canopus ADVC110 in Color Bar mode -> JVC VCR via composite for recording.
    Captured: Using the new JVC VCR via S-Video and my old Sharp VCR via composite to the Canopus unit.

    TV clip
    Description: A TV clip recorded off of broadcast cable around 2001.
    Recorded: With a standard consumer VCR (I don't have it anymore).
    Captured: Using the new JVC VCR via S-Video and my old Sharp VCR via composite to the Canopus unit.

    Camcorder clip
    Description: VHS camcorder footage from around 1987. Could be multigenerational.
    Recorded: With an old Zenith camcorder that was purchased back in 1983.
    Playback: On the new JVC VCR via S-Video and my old Sharp VCR via composite to the Canopus unit.

  • #2
    Are you using the optional power supply for the ADVC110? It might be a problem of not-quite-enough FireWire bus power.

    Comment


    • #3
      Sorry to resurrect such an old post but I was never able to figure out the problem.

      I have now confirmed the issue with many different VHS tapes (from different camcorders).

      The waveforms of the captured video through the Canopus results in video information between digital 0-16. I am forced to bump things up by 16 units in order to get properly balanced video. When viewing the tapes on my TV directly through the VCR things look great. But playing the captured video back on the TV shows significant black crush.

      Can anyone think of a reason why the luma values are lowered in my captured video?

      I am really confused as to what is going on.

      To answer the last question, yes I am using the power brick with the Canopus.

      Thanks!
      Last edited by frenchFry; 04-18-2009, 08:57 AM.

      Comment


      • #4
        Depends on how your tapes were recorded.
        If they were recorded at IRE 0 setup, you should capture with the ADVC set to IRE 0 setup.

        If they were recorded at IRE 7.5 setup, you should capture with the ADVC set to IRE 7.5 setup.

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