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    #11
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    Quote Originally Posted by ed_lee83 View Post
    I admit it's hard to tell immediately the differences in video quality. But for me, a frequent user of ETC mode, I can say that the grain is a lot smoother. Same case for higher ISOs in normal mode.
    The bit rate that the camera encodes to varies directly with an increase in ISO value. The amount of noise actually affects the bit rate more than the amount of motion does.

    Think of it this way. Noise is the constant changing of individual pixels throughout the picture. Even if you have very fast motion in a frame the moving subject does not always cover the entire frame. Noise is by far the hardest thing to compress without a quality loss. It stands to reason that using an extremely high bit rate would help accurately represent the noise. However, it is up to the viewer to determine whether that is a good thing or a bad thing.


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    #12
    Senior Member GrahamH's Avatar
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    Modestly hacking the bitrate upwards is absolutely worth it if you use the 720P mode! Shoot someone dancing, or whatever, in front of a foliage background and watch the background - not the dancer - in playback. On an unhacked GH2 you will see a strange kind of pulsing effect, which goes away with a 32Mbps bitrate hack applied.


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    High ISO and noise reduction
    #13
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    The comment about bitrate and high ISO is right on the mark. I know many people suggest setting noise reduction at -2, I think in some cases this is ill advised. If there is a lot of noise the codec will be consumed with encoding it - to the detriment of doing a better job with more useful image elements. Over doing noise reduction obviously degrades detail, but up to the point where you reach the signal to noise ratio it should be helpful. The higher the ISO, the lower the S/N ratio, so the higher you can set noise reduction without removing any real detail. This is a different issue than sharpening - which never adds any real detail, rather it forces the codec to consume itself with the fake detail sharpening produces.

    Chris


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    #14
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    Quote Originally Posted by cbrandin View Post
    The comment about bitrate and high ISO is right on the mark. I know many people suggest setting noise reduction at -2, I think in some cases this is ill advised. If there is a lot of noise the codec will be consumed with encoding it - to the detriment of doing a better job with more useful image elements. Over doing noise reduction obviously degrades detail, but up to the point where you reach the signal to noise ratio it should be helpful. The higher the ISO, the lower the S/N ratio, so the higher you can set noise reduction without removing any real detail. This is a different issue than sharpening - which never adds any real detail, rather it forces the codec to consume itself with the fake detail sharpening produces.

    Chris
    Some people actually want to retain that noise detail. In some ways having well defined noise is better than having noise that is smeared(even a little) from noise reduction or compression.

    Anyway, the hacking game is about to change thanks to Chris and VK. The next Ptool will offer settings that everyone can live with. Thanks for your efforts. I think it is safe to say that the GH2 is the most highly desirable video camera thanks to what you guys have done.


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    #15
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    Good point. In many cases, however... Can't you add well defined noise (or any kind of noise you want, for that matter) in post? I wonder if you could see the difference. It seems like there might be a balance here - the more noise that remains because of no NR, the more that noise will end up being corrupted by compression because the encoder runs out of bandwidth.

    Chris


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    #16
    Senior Member Skeptikal's Avatar
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    While the AVCHD is still plodding a bit, the hacked GH2 gives a superb 1080p MJPEG @ 100 mbps. I'm keeping my GH13's for the AVCHD/25p...but the GH2 for when I need MJPEG @ 30p. Best of both worlds...


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    #17
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    Quote Originally Posted by Skeptikal View Post
    While the AVCHD is still plodding a bit, the hacked GH2 gives a superb 1080p MJPEG @ 100 mbps. I'm keeping my GH13's for the AVCHD/25p...but the GH2 for when I need MJPEG @ 30p. Best of both worlds...
    1080p @ 24 FPS and 42 mb/sec is vastly superior to MJPEG even at 180 mb/sec. VK's latest Ptool build has completely stable and optimized 42+ mb/sec 1080p,720p, and 1080i. If you haven't tried Chris's new optimizations then you have experienced really high quality video.


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    #18
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    Quote Originally Posted by GrahamH View Post
    Modestly hacking the bitrate upwards is absolutely worth it if you use the 720P mode! Shoot someone dancing, or whatever, in front of a foliage background and watch the background - not the dancer - in playback. On an unhacked GH2 you will see a strange kind of pulsing effect, which goes away with a 32Mbps bitrate hack applied.
    GrahamH is right. The hack is good and cool for 24p, but for MJPEG and 720 modes, it's a godsend.


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    #19
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    So with this hack my GH2 will in simple terms resolve more detail in 72P.


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    #20
    Senior Member Danielvilliers's Avatar
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    The devil is in the detail here. If you do grade your shot, the hacked gh2 (GH23) is much better. You don't see the typical macro block that usually pop up when the image breaks down. In shadows you will see marked improvement. Where it was a mush before now you can see details.


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