Personal View site logo
VIDEO: Panasonic GH1 - 100Mbps Hack Test
  • I just posted this over at Vimeo. Thought I would post it for everyone to see, here.
    Thanks for all your hard work Vitaliy!!!



    This test was filmed using an "unhackable" Panasonic GH1. The model GH1 I had was "unhackable" until its firmware was recently hacked again by Vitaliy Kiselev. The hack was made available on May 29, 2011, using PTool 3.55d.

    The hack profile settings I used for this video allow the camera to record file speeds of up to 100Mbps. This setting is not meant to be used all the time as it may cause the camera to cease recording when filming extremely detailed scenes like foliage. So to test this, I filmed...some foliage.

    Most of my foliage shots (and a few shots of my beagles) were under 30 seconds. Some people report that their camera shut down after only 6-10 seconds of filming foliage with the 100Mbps patch. My camera did not give me any problems at all with the 100Mbps patch, though.

    I checked out the video MTS clip files with MediaInfo and the "Maximum Overall Bitrate" is listed at 108 Mbps. Keep in mind that this doesn't actually mean that the file actually ever hit 108Mbps.
    LPowell explains this :
    "The 108Mbps figure that MediaInfo reports is metadata recorded in the file header by the AVCHD encoder. This tells the decoder in advance the maximum bitrate it must be prepared to decode. In practice, I have only rarely seen peak bitrates exceed 100Mbps in test files I've shot with the Max Latitude Patch. The 1-17Mbps readings are running average bitrates, which can range up to 40-50Mbps. The GH1's AVCHD encoder begins each clip with a key frame encoded with a low bitrate which then increases over time, and varies depending on the complexity of the subject matter."

    Also - I wanted to test the GH1 with my Canon 70-200mm f/2.8L zoom lens. I attached the lens to my GH1 via a $30 Fotodiox EOS-MFT lens adapter.

    Note that my copy of the Panasonic GH1 has some banding issues. The serial number on my camera starts with WE0G****, which means it's manufacture date was July 2010. Supposedly, the GH1 can be purchased brand new and with manufacture dates as recent as March 2011. The newer the manufacture date, the less the banding is supposed to be.

    The next 2 tests that I will do with my newly hacked GH1 and it's 100Mbps patch are the following:
    1. Grass shot, locked down on tripod.
    2. Star chart test.
    For both of these high-detail tests I will let the camera roll for as long as it will roll. I will also be using a sharp, wider Canon L series lens. My goal is to see how long of a shot I can get before the bitrate goes too high for the camera, buffer or SDHC card to handle.

    Also - soon I will be posting some footage with the Canon L Series lenses and my Panasonic GH2. Then we can compare the quality of the hacked GH1, and the unhacked, newer GH2.

    Then finally, when Vitaliy hacks the GH2, I'll post footage of the hacked GH2!

    - - - - - - - - -

    EQUIPMENT, Etc:

    Camera: Panasonic GH1
    Serial: WE0G****
    Hacked Firmware: 100Mbps Max Latitude Patch V2
    Film Style: "SMOOTH" (-2, -2, 0, 0)

    SDHC Card: 32GB Transcend (Class 10)

    Lens: Canon 70-200mm f/2.8L
    Aperture: 2.8 (because the Canon EOS lens system does NOT have a MANUAL aperture, the aperture has to be set on a Canon EOS camera body...then taken off and attached to the GH1, and used with whatever aperture was set on the EOS body).
    Shutter speed: Varies due to having to keep the aperture at 2.8
    ISO: 160 exterior shots...between 400-640 indoor shots

    CC: FCP 3-Way Color Correction (only used to correct exposure...I didn't have my LCD brightness set proper when recording)
  • 4 Replies sorted by
  • There's something wrong with the motion in the trees/leaves footage, i guess it's the shutter that you let it run on. You should use an ND or VariND and lock that shutter.
  • how do you lock the shutter speed
  • GH2- Put into shutter priority mode (should be same with GH1) (S)

    http://en.wikipedia.org/wiki/Program_mode

    Set to 50 for 24-25p and go up from there, not down, (for normal video)
    In the good old days you couldn't change: Shutter or ISO (film stock).
  • @blackseedz

    "how do you lock the shutter speed"
    In Gh2 (YMMV) go into "exposure" in the menu - and select S.