@svart

Just remember to note that this is true if you talk about 24H.
But difference is noticeable in motion or in high detailed scenes.

As for stability, look for stable settings topic. We already have much more stable function comparing to GH1.

@Vitaliy

Are there any examples that show MUD or compression artifacts even with moderately higher bit rates? I haven't seen any evidence that higher bit rates really are necessary even with moderate motion.

The problem is that everyone just says “This looks better to me”. That isn’t telling us anything . You have to compare the exact same image for the settings side by side. Let’s see some screen shots of the differences. It is really easy to do a screen shot. Just use VLC and let it save it as a png file.

@mpgxsvcd

I'm not a tester, but hasn't Vitaliy said the difference is most noticeable in shots with motion? So will a screen shot be instructive? Seems like we need full motion video to assess.

@mpgxsvcd , By the submission that noise is easier to see with the higher bitrate -This discovery alone tells us that the finer details (such as noise) and other finer image details are now being rendered visible.

I have two GH2 cameras, one with the hack, the other stock. This weekend I will set up some low light shot comparisons and display them here.

BTW, I just read your above post. Yes, I do agree with you. As it's been mentioned here, the GH2 at 1080 24P Cinema mode does produce a good image on its own. I do believe it has improved using higher bitrate in low light detail and motion such as pan movement and high detailed moving images such as water.

My real question is these two scenarios:

1. low light video shot at low ISO with little detail such as flat walls. With a low ISO setting, the codec will not be forced upon a higher bitrate. This may still cause less detail in the shadows and possible mush.

2. low light video shot at low ISO with lots of fine detail. The fine detail in the video will increase the bitrate; therefore, the low light footage should have better detail and less mush in the shadows.

Ideally VK and Chris and all other gurus will figure out how to increase the lowest bitrate which will force a higher average bitrate under the same conditions.

Great work to all here man!

@proaudio4

Yes there is a difference. Between the stock and modified bit rates. No doubt about that. Especially in noise rendering. You can see it in the pictures I posted. The stock firmware will simply smear the noise out. This may or may not be desirable depending on what you are looking for.

The real question is how is this smearing affected by higher bit rates. There has to be a point at which the bit rate is ample to render an accurate image of the noise as it was recorded by the sensor. The problem is that we cannot determine where that point is without doing very systematic testing.

I have done that testing up to 42 mb/sec and I believe it shows that there really isn’t much gain by going over 32 mb/sec. It is really hard to tell which picture is which for the higher bit rates. I will also post the rest of the videos to Vimeo tonight(I ran out of upload cap so I couldn’t post them last week).

There is no need to do the tests with two separate cameras. Testing a camera with nothing checked but the version compare is sufficient to test the default settings. In fact it is better to test with a single camera fixed in one spot on a tripod.

When I ran my tests I never moved the camera at all. I simply swapped the SD card out every time I updated the firmware. I didn’t even remove the legacy 55mm Canon FD lens in-between tests. The GH2 accepted the new firmware even without an m4/3s lens on it.

I really would just like to see someone else show the differences they are seeing instead of talking about how great the results are. Vitaliy has been asking for this all along but no one seems to listen anymore.

@mpgxsvcd

I agree. I need to find a local spot that I can find the same type of motion and potential artifacts to test.

@proaudio4

"1. low light video shot at low ISO with little detail such as flat walls. With a low ISO setting, the codec will not be forced upon a higher bitrate. This may still cause less detail in the shadows and possible mush."

I did this scenario and it produced the exact same bit rate regardless of the settings used. If the camera doesn't determine that it needs a higher bit rate then it will act just like stock even with the hack applied. This is where Vitaliy and Chris's work will probably show the most benefit.

Gotta push the limits of GH2 to see noticeable difference.

Deep DOF on complex objects. e.g. Maple tree. There should be no mud.

Fast moving object with deep DOF. Less mud.

Black area details in low lighting. Raise ISO. 1250 or higher. More natural looking noise.

Not clipped highlight. Try overblown highlight scene. I don't know. Is there any difference?

Not sure about shallow DOF.

@mpgxsvcd Yes, I do agree. I also would like to see tests done on the two scenario/s.
I mentioned above.

I will also post some footage where I accidently shot 720 60P (6 GOP) at 35mb/s. I thought I had selected 42mb (6 GOP).

This 720 60P 35mb/s footage shows someone on a skateboard in lower light with a fence in the background.
The skateboarder image falls apart in motion. It's very strange. His arms look like they are bent.

I did something similar to this using the "cat of death" which routinely broke GH1 codec settings. My cat has very strange fur patterns and his fur has multiple layers of light and dark on each hair which make for a pattern very close to the pattern of death chart.

I shot two files of his back while he was sleeping and compared the light/dark areas both in and out of the overhead light.

While I don't have the files anymore, the outcome was this:

24H stock and 24H GOP3/65mb(Kae's setting) looked similar in both the lighted and non-lighted situation. The 65mb setting had slightly less muddy dark areas but 3x the filesize. That's about it.

I did the same thing with a tree outside:

24H stock showed slight macroblocking in the dark areas of bark and shaded leaves. 24H with 3GOP/65mb(Kae's setting again) there was less macroblocking in both the bark and the shaded leaves but there was no discernible enhancement in detail in the well lit portions.

I'm also of the opinion that finding a way to increase the lower bitrate limit will improve the areas of problems that I've seen. VK has mentioned a number of times that the 24H codec is much improved from the GH1 24p. I think this means that we will not see the drastic increase in quality from bitrate increases that we saw on the GH1. We'll see minor increases in quality in raising the upper bitrate only.

I tried it out myself, if you shoot low motion, stick with standard bitrate if youre shooting 24p, but if youre smart, you can configure your cam to shoot in standard 22mbits on 24L and higher one, like 42 or 65mbits at 24H, so you can decide on location.

High motion, especially at high shutter speeds with no motion blur benefits highly from bitrate increase, also from low gop.