GH2 official discussion thread

Adventsam said:
In raw?, I think 1 stop is a bit of an over-exageration detail in gh2 is beyond d7k all the way!, now, according to dxo, GH2 is well behind GH1 for iso, no way on this planet, and this is the problem, they are measurements, just that, they mean didly squat in the real world and they are their measurements, honestly they are marketing front for their software, its complete XXXX all this overall rating ....
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I looked at both RAW and JPEG comparisons and that's what I see. Don't forget, everyone's eyes (and perceptions) are different, so what I stated is simply my opinion and observation.

In regards to DXOMark, frankly, I do not know the details of their testing methods or what some of the specific results like "ISO score" performance actually mean. If you do, I think it would be more helpful if you detailed exactly how they are wrong, preferably with some "backup" instead of just making statements like "DXO is XXXX"

... as for GH1 sensitivity above GH2, it is miniscual and not 1 stop. upto you believe dxo but it is meaningless and equates to nothing.
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If you compare the charts, the difference is actually about 1/2 EV. IMHO, it is a good thing that GH2's ISO ratings are in line with nominal measurements versus understated (GH1) or overstated (7D, 60D), which makes product comparison a little easier. I just think it is important to keep this difference in mind. 1/2 EV is not an insignificant difference. BTW, a long time ago I have learned to form my opinions based on cross-checking facts and data and sometimes other opinions, so don't worry, I don't take a single source too seriously unless they gain a reputation (with me) for being spot on more often than not ;)

While we are talking about comparison, since video is processed (not RAW) sensor data, the bigger impact on video IQ may actually be derived from improvements in processing hardware and software rather than the sensor itself. To my knowledge, neither DXOmark nor dpreview really make any sort of systematic testing in this area. Hopefully, Barry has gotten himself a GH2 in Japan as well, so we'll soon see both the eye-candy from him and Phillip, as well as "charts" and tests for us arm-chair engineers as well :)
 
For someone like me who doesn't want banding at at high ISOs, should I really care what DXO states when it comes to video? Out of the GH1 and GH2 which will give me less banding? Shouldn't that matter more than what are their scores are for RAW photos?
I shot a concert in which I had to use an ISO of 500 or it would have looked too dark and I couldn't stand the little banding I was seeing.

Rather DXO are reliable or not, should not make a difference in shooting video in low light situations.
 
No you shouldn't care what DXO says at all, there tests are obviously incapable of measuring banding, as ALL the video I have seen from the GH2 has far less banding than the GH1(actually I notice no banding at all at least up to 3200 ISO). As it is alot of the time with many imperial statistics, DXO tests only seem to cover a very small subset of what makes for a superior high fidelity image, as everything else I have seen and read about the GH2 video as well as stills from every other source seems to fly in the face of their "findings"
 
got my issue of Outdoor Photographer today in the mail, and a few pages in is a full page ad for the GH2....with a 3D lens stuck on the front....now, i know it's a magazine thats more about still photography, but most of the description leans toward its video capabilities. just seemed like a goofy way to roll out this new cam. ?
 
svecher said:
I looked at both RAW and JPEG comparisons and that's what I see. Don't forget, everyone's eyes (and perceptions) are different, so what I stated is simply my opinion and observation.

In regards to DXOMark, frankly, I do not know the details of their testing methods or what some of the specific results like "ISO score" performance actually mean. If you do, I think it would be more helpful if you detailed exactly how they are wrong, preferably with some "backup" instead of just making statements like "DXO is XXXX"

If you compare the charts, the difference is actually about 1/2 EV. IMHO, it is a good thing that GH2's ISO ratings are in line with nominal measurements versus understated (GH1) or overstated (7D, 60D), which makes product comparison a little easier. I just think it is important to keep this difference in mind. 1/2 EV is not an insignificant difference. BTW, a long time ago I have learned to form my opinions based on cross-checking facts and data and sometimes other opinions, so don't worry, I don't take a single source too seriously unless they gain a reputation (with me) for being spot on more often than not ;)

While we are talking about comparison, since video is processed (not RAW) sensor data, the bigger impact on video IQ may actually be derived from improvements in processing hardware and software rather than the sensor itself. To my knowledge, neither DXOmark nor dpreview really make any sort of systematic testing in this area. Hopefully, Barry has gotten himself a GH2 in Japan as well, so we'll soon see both the eye-candy from him and Phillip, as well as "charts" and tests for us arm-chair engineers as well :)
Click to expand...

+1:happy:
 
Dazza said:
No you shouldn't care what DXO says at all, there tests are obviously incapable of measuring banding, as ALL the video I have seen from the GH2 has far less banding than the GH1(actually I notice no banding at all at least up to 3200 ISO). As it is alot of the time with many imperial statistics, DXO tests only seem to cover a very small subset of what makes for a superior high fidelity image, as everything else I have seen and read about the GH2 video as well as stills from every other source seems to fly in the face of their "findings"
Click to expand...

+1zillionnnnnnnnnnnnnnnn!!!!!!!!!!:Drogar-Happy(DBG):

I see no banding and iso3200 shots I have seen from GH2 are really really good, sharp, detailed, no CA etc etc, I could gladly use it for sports at iso3200, but dxo says gh2 only good to 600 or something, behave dxo!
 
Just thought I'd drop this in for people that are interested to see how far all this "pxxxxing" contest is going, Pentax users think the focus wasnt right on their shots versus Canon, and so on we go. As I say, dpr do give the evidence to make a subjective "personal" review by eye of what appeals to you, dxo give a load of data and expect everybody to accept their results, if thats what tickles you cool, but with out real photso from the full-chain of the device, I repeat it means absolutley nothing in the real world, and to cap it all they now give every camera a score, get real dxo, do your calculations but to score cameras without any subjective images is an absolute joke. Just look at these jokers having a go at dpr because they didnt use f5.6 to compare sharpness, they used f9 to get everything in focus, oh but yes diffraction is setting in, oh get a life!

As an aside, because m43 uses Contrast detection for af, it nails focus time and time again, not so with phase detection(it can nail focus) but the system and plane of sensor and lenses can front and back focus, hence you get lense adjustment in the menu for high-end dslr! sooner that all manufacturuers move to mirrorless the better.

http://forums.dpreview.com/forums/read.asp?forum=1036&message=36904571
 
Thanks for that billh. Lefournier also said this, on the Vimeo thread: I had a 1080p / 24p on GH2 but I prefer to use 720p which is my preferred method to avoid problems and strobe, rolling shutter and also be able to slow motion through the 50 fps 720p So I guess we are looking at 17Mbps capture ... reading between the lines, he may have thought he was capturing at 24Mbps.
 
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Thank you Graham. Does that mean the sole advantage of the GH2 over the hacked GH1 is the AF speed (“The incredible speed of the autofocus will remain the no. 1 innovation of the GH2” )?
I also heard AVCHD is limited to 24Mbps - but if so, how can higher rates be obtained in the hacked GH1?

I wonder how long it will be before we are treated to a GH2 hack?
 
The more I think and talk to people the more I understand that we don't have 1080p60/p50 not because purely technical reasons, but because monkey learned the lesson.
They released 17Mbps codec with mud in GH1, etc. And now they are bound at 21.4Mbps(video rate only), most probably without B frames (due to encoder restrictions, so it is almost the same GH1 encoder), and at 1080p60.
This won't look good. Even with B frames you need 28Mbps and full fledged encoder (ala TM700) to make it look good.
At 1080i it'll look better.
And at 1080p30/p25 it could start to look worse again due to more hard work of motion prediction.
This could be real reasons behind modes that we see now.
 
how come this footage which suppose to be native 24p is 23.976 fps?
i am a bit confused
http://vimeo.com/16606700


Format : BDAV
Format/Info : Blu-ray Video
File size : 30.8 MiB
Duration : 11s 219ms
Overall bit rate : 22.9 Mbps
Maximum Overall bit rate : 24.0 Mbps

Video
ID : 4113 (0x1011)
Menu ID : 1 (0x1)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.0
Format settings, CABAC : No
Format settings, ReFrames : 2 frames
Format settings, GOP : M=3, N=12
Codec ID : 27
Duration : 10s 927ms
Bit rate mode : Variable
Bit rate : 21.8 Mbps
Maximum bit rate : 21.7 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.438
Stream size : 28.4 MiB (92%)
 
Can somebody in Japan, who has the GH2 now test, how the picture taking during filming works?
In 720 and in 1080?
If there are sound breaks when the picture was taken and if the film runs completely though without stopping?

Also I have heard, that there is an advanced technology implemented, who to get still pictures from the AVCHD footage.

Does this work and what does the footage look like?

Thanks
 
John Caballero said:
Because that is the way it is in NTSC land and the codec. It is not true 24 fps.
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wierd.. so this clip:
http://vimeo.com/16497211
(which i downloaded somewhere as MTS)

is true 24p from the GH2. no?


General
Complete name : G:\importand c documents\desktop stuff\31930539.mp4
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42
File size : 227 MiB
Duration : 1mn 18s
Overall bit rate : 24.1 Mbps
Encoded date : UTC 2010-11-03 17:46:25
Tagged date : UTC 2010-11-03 17:46:25
©TIM : 00:00:00:00
©TSC : 24000
©TSZ : 1001

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L4.2
Format settings, CABAC : Yes
Format settings, ReFrames : 3 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 1mn 18s
Bit rate mode : Variable
Bit rate : 24.0 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 24.000 fps
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.482
Stream size : 225 MiB (99%)
Language : English
Encoded date : UTC 2010-11-03 17:46:25
Tagged date : UTC 2010-11-03 17:46:25

those are the manual formats- so how come the 24 wrapped footage is higher than 17Mbs?
 

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> And now they are bound at 21.4Mbps(video rate only) most probably without B frames ........ at 1080i it'll look better.

I thought the only GH2 mode that is blessed with an elevated rate is 24P at 24Mbps, and that all the other modes including 1080i are still stuck at 17Mbps?
 
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@roei z - we posted at the same time.

You are asking how come the 24P wrapped footage is higher than 17Mbs .... in the first thumbnail from the manual that you posted, you can see there are two flavors of 24P - 24Mbps and 17Mbps. The other 1080 options (which you highlighted in the second thumbnail) are interlaced 60i/50i and only 17Mbps (which sucks).
 
GrahamH said:
@roei z - we posted at the same time.

You are asking how come the 24P wrapped footage is higher than 17Mbs .... in the first thumbnail from the manual that you posted, you can see there are two flavors of 24P - 24Mbps and 17Mbps. The other 1080 options (which you highlighted in the second thumbnail) are interlaced 60i/50i and only 17Mbps (which sucks).
Click to expand...

yea but that's suppose to be 24p native, so where's the not true 24p comes from?
 
yea, i know the differences, but i'm asking how come the GH2 (on pal or ntsc) which suppose to have true 24p, is outputing a 23.976 (or 25.00) framrate file ? i suppose to get a 24.00 framerate, not a wrapped one -
that's the big difference in GH2, no?

*ok, got it (not very knowledgeable on this). there is no "strait" 24p at all, never. the difference in the GH2 NTSC is that it records to true 23.976 frames and not wrapping it in 60i, right ?
so it's a bit less post work afterward...
 
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