GH2 official discussion thread

[GrahamH]

I was also a bit baffled that the Sensor Comparison on dxomark ranks the unhacked GH1 higher.
http://www.dxomark.com/index.php/eng/Camera-Sensor/Compare-sensors/(appareil1)/630%7C0/(appareil2)/677%7C0/(onglet)/0/(brand)/Panasonic/(brand2)/Panasonic

Any thoughts?

The dxomark score relates to the raw unprocessed signal at the sensor, and takes no account of in-camera processing of the final image. The GH1 and GH2 scores are almost identical - close to the errror variation of their methods - and since the GH2 has much more powerful processing it will produce a better final image. That's my $0.02, anyway.

 

[Adventsam]

I was also a bit baffled that the Sensor Comparison on dxomark ranks the unhacked GH1 higher.
http://www.dxomark.com/index.php/en...nglet)/0/(brand)/Panasonic/(brand2)/Panasonic

Even thought i hope this is due to a pre-released beta model, i am still a little concerned...

Any thoughts?

They are near identical, but the lack of low ISO settings is hurting the overall result imo. Dxo are putting a lot of emphasis on the score for DR, hence the Pentax result. Panasonic should try and squeeze more DR out at low ISO, infact they should add ISO25-50-75-100-125 anyway, even if its artificial to help get the shutter speeds down, especially for Photography. I wish I knew why they started at ISO160, really annoying. Plus, real world is that banding is almost gone to 6400, probably about 3200-5000 it will start to appear, so well suppressed for video hence max iso3200 setting. Anyway if banding is gone and almost identical results and more pixels etc etc, GH2 is a winner, just wish they'd added a 25p pal 24mb, ahhhhhhhhhh

 

[muroshi]

Is someone working on a 25p hack now or shall I buy a 550D?

 

[kloned]

Is someone working on a 25p hack now or shall I buy a 550D?

If you're waiting for this hack, better buy 550D. There are (at least) 5 reasons for that:
- for this moment (as I suppose from Vitaliy Kiselev signature status) nobody is working on GH2 hack;
- just no guaranty that is possible to enable this feature through binary patch;
- nobody knows if GH2 is hackable in general;
- hack process itself could take a good amount of time;
- the guy who will work on GH2 hack may not be interested in this feature at all

 

[Adventsam]

Barry Green has a GH2?

http://yfrog.com/6e1cugj

So has Bloom I think, not sure if they are just messing around or are seriously in possession of them, but cant see why they dont have them!

 

[GrahamH]

The next photo in the series indicates they were both at a "Panasonic VIP Group dinner" in Japan. And that caption to the Barry Green photo says the camera "isn't his".

 

[Uwe Lansing]

The next photo in the series indicates they were both at a "Panasonic VIP Group dinner" in Japan...

Perhaps this was the flight in that direction: http://vimeo.com/16618194

 

[svecher]

Switching tracks here a little bit, richtrav has kindly provided some samples of 720/60p footage from his release GH2 camera, which I ran through the GH13Parser.



As you can see B-frames are absent, which is something we've known from pre-production camera samples, but this is now confirmed. This is a bit unfortunate, as I actually use the 720/60p on GH13 for either slow-motion shots or fast-action sequences, like surfing footage. Given what we know about firmware in GH1 (every mode is essentially standalone code) I wonder if firmware in GH2 is structurally similar to one in GH1, with one of the differences being that code for 1080 codes was changed to include B-frames (and higher bitrate ceiling for 24p mode).

 

[Vitaliy Kiselev]

This is really not good.
It looks like firmware had been renamed from 0.3 to 1.0 and flashed to allow shipping of production bodies.
Other option is that chip encoder hardware are unable to analize matches for two frames at 60fps even in 720p.
May be that we see here is real source of 50i/60i modes.

 

[mpgxsvcd]

This is really not good.
It looks like firmware had been renamed from 0.3 to 1.0 and flashed to allow shipping of production bodies.
Other option is that chip encoder hardware are unable to analize matches for two frames at 60fps even in 720p.
May be that we see here is real source of 50i/60i modes.

Interesting theory. So if this is the case then 1080i would have a much lower resolvable vertical resolution than even the 720p would, right?

 

[Adventsam]

What is the analysis for the 50i/60i format?

 

[Vitaliy Kiselev]

Interesting theory. So if this is the case then 1080i would have a much lower resolvable vertical resolution than even the 720p would, right?

No. And drop this theory of inferior resolution in 1080i
In reality 1080i frame consist of two subframes each is 1920x540.
Each subframe also devide into slices, and encoder search for matches only between same slices. This is my understanding.

 

[mpgxsvcd]

No. And drop this theory of inferior resolution in 1080i
In reality 1080i frame consist of two subframes each is 1920x540.
Each subframe also devide into slices, and encoder search for matches only between same slices. This is my understanding.

Sorry I was just trying to understand what you stated. It wasn't completely clear. Were you suggesting that 1080i could be sourced from 720p? Please correct me if I misread your post.

 

[stonebat]

This feels like... having 800 pound gorilla in a room. I really hope panny didn't close all loopholes for future hack. If GH2 is shipped with firmware 1.1 in the states, it could take several months before having 1.2. There's no new Panny m43 lens in 1st half of next year.... OMG!!! Sky is falling!!!!

Ok... Let me calm down. that's just fine. No banding... no banding... no banding...

 

[svecher]

This is really not good.
It looks like firmware had been renamed from 0.3 to 1.0 and flashed to allow shipping of production bodies.

Well, to be fair we don't know what other changes went into fw 0.3 to make it 1.0. It seems that ugly horizontal blue bands are gone, so that's certainly a positive development.

Other option is that chip encoder hardware are unable to analize matches for two frames at 60fps even in 720p.
May be that we see here is real source of 50i/60i modes.

Interesting. Now, I don't know how close in complexity the algorithm for contrast autofocus is to motion vector analysis one, but it does work at 120 fps, albeit at lower than 1080 resolution as I recall you saying. This puppy does have 3 Venus chips after all. My guess is they never even touched 720p code, because they figured people would either fall in love with the new Cinematic Mode or the iSmooth 1080. 720p -- that's so 2009!

Now, maybe we'll get lucky in that someone didn't get the memo and copied GH2 fw 0.3 from GH1 fw 1.32. Now that would be pretty exciting

 

[Lpowell]

As you can see B-frames are absent, which is something we've known from pre-production camera samples, but this is now confirmed. Given what we know about firmware in GH1 (every mode is essentially standalone code) I wonder if firmware in GH2 is structurally similar to one in GH1, with one of the differences being that code for 1080 codes was changed to include B-frames (and higher bitrate ceiling for 24p mode).

This Stream Parser chart of a GH2 720p60 video stream looks identical to what a stock GH1 would produce. My suspicion is that the only significant change to the GH2 AVCHD encoder is the addition of a brand new 1080p24 24Mbps mode. As for MJPEG, the GH2 specs indicate that nothing has changed at all.

 

[svecher]

This Stream Parser chart of a GH2 720p60 video stream looks identical to what a stock GH1 would produce. My suspicion is that the only significant change to the GH2 AVCHD encoder is the addition of a brand new 1080p24 24Mbps mode. As for MJPEG, the GH2 specs indicate that nothing has changed at all.

That is my assessment as well. Perhaps Vitaliy can get a backport patch going (if and when -- I'm patient) ... Time to revisit "Emotions and Crazy Ideas" thread?

 

[kloned]

A set of casual and testing GH2 videos, didn't mentioned here yet

Lowlight:
If I'm not wrong, here is a comparison with TM750 http://www.youtube.com/watch?v=-tp5Umj5yrk&hd=1
High ISO capabilites http://www.youtube.com/watch?v=uoBt-6K_PwE&hd=1
EF50mm F1.8 http://www.youtube.com/watch?v=FECTl7mmIlY&hd=1
Just nice one http://www.youtube.com/watch?v=4DPuX_I3Lks&hd=1
EX Tele Conversion http://www.youtube.com/watch?v=oOYFwd6Bp3A&hd=1

Mixed:
Sport mode http://www.youtube.com/watch?v=90E7_FSXXlY&hd=1
"Bird" series with Nikkor 300mm f/4D, and different modes:
1. http://www.youtube.com/watch?v=dU-x0xaJ6fw&hd=1
2. http://www.youtube.com/watch?v=NWiX6BJFTGM&hd=1
3. http://www.youtube.com/watch?v=MLPLcPnwsTI&hd=1
From airplane http://www.youtube.com/watch?v=Kz-kBZMRQps&hd=1
Good test "on the field" http://www.youtube.com/watch?v=PuUkyygnqf8&hd=1
Some random samples using 14-140 kit http://www.youtube.com/watch?v=bKJMlRlVfaU&hd=1

Enjoy !

 

[stonebat]

ORLY? Panny stupid or what? I presume we can have the same set of hacks if it's hacked. Reliable, high Mbps, fast motion, etc. e.g. Reliable 100Mbps 24pN. Drool... that would be a treat.

 

[blafarm]

Switching tracks here a little bit, richtrav has kindly provided some samples of 720/60p footage from his release GH2 camera, which I ran through the GH13Parser.

View attachment 25466

As you can see B-frames are absent, which is something we've known from pre-production camera samples, but this is now confirmed. This is a bit unfortunate, as I actually use the 720/60p on GH13 for either slow-motion shots or fast-action sequences, like surfing footage. Given what we know about firmware in GH1 (every mode is essentially standalone code) I wonder if firmware in GH2 is structurally similar to one in GH1, with one of the differences being that code for 1080 codes was changed to include B-frames (and higher bitrate ceiling for 24p mode).

At the risk of stating the obvious, and assuming the HDMI signal fully-tracks the camera setting profile, I'm guessing the problem goes away with an external recorder.