GH2 official discussion thread

Thanks for these samples Roei!

I've been trying to work out what the bitrate the GH1 would have to be to match the GH2.

There's 20% less data to encode in 24p (as it's native, not wrapped in 30i).
There's a 20% boost in encoding efficiency down to B-frames.
There's 30% more bitrate than the GH1 (at default 17Mbit).

So, for the GH1 to match the GH2's video, it would have to run at 31Mbit, if my calculations are correct. Not too shabby, really, especially as it would be 100% reliable.
 
Matthew P said:
Thanks for these samples Roei!

I've been trying to work out what the bitrate the GH1 would have to be to match the GH2.

There's 20% less data to encode in 24p (as it's native, not wrapped in 30i).
There's a 20% boost in encoding efficiency down to B-frames.
There's 30% more bitrate than the GH1 (at default 17Mbit).

So, for the GH1 to match the GH2's video, it would have to run at 31Mbit, if my calculations are correct. Not too shabby, really, especially as it would be 100% reliable.
Click to expand...

how is the stress test on HD screen? didn't have time to watch
 
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Hi roei, thanks for the test, I don't know if it is my settings (screen and player windows media) but I can only see white walls (blown) and black silhouettes (crush shadows). The above scene is really an extreme where I think only an Alexa or more so red hdrx would come out ok. It would be nice to see perhaps less stressful (contrasty) scene and skin roll-off are very important. Again it is dig at you, because I am very grateful to have someone doing all those test here.

I would like to know if there are any test on the net showing hdmi capture relative to dynamic range (gains or not) for any camera. Something like the canon hv20 or any other camera, just to know if we can expect any gains.
 
roei z said:
how is the stress test on HD screen? didn't have time to watch
Click to expand...

Not too shabby in regards to the codec. It's hard to see any artifacts when the picture is in motion, which is quite something because there's a LOT of detail in there that could have been lost if the codec wasn't up to it. But if you get a bit closer and really look for artifacts, there are plenty to be seen.

The rolling shutter is clearly visible, but not too bad. I don't know how a GH1 would've pared up to it.
 
Matthew P said:
...
I've been trying to work out what the bitrate the GH1 would have to be to match the GH2.

There's 20% less data to encode in 24p (as it's native, not wrapped in 30i).
There's a 20% boost in encoding efficiency down to B-frames.
There's 30% more bitrate than the GH1 (at default 17Mbit).

So, for the GH1 to match the GH2's video, it would have to run at 31Mbit, if my calculations are correct...
Click to expand...

I don´t know whether it is right or wrong but it sounds good to me...
 
roei z said:
how about VLC ? not good?
Click to expand...


Didn't try it, sorry.

I don't like VLC much, although I know some people swear by it.

The effect in Splash was really odd - as if you were constantly changing aperture with the consequent lightening & darkening of the image (rapidly)

Good in the other two, though - a fine noise grain, nothing objectionable at all.
 
Framerate said:
Didn't try it, sorry.

I don't like VLC much, although I know some people swear by it.

The effect in Splash was really odd - as if you were constantly changing aperture with the consequent lightening & darkening of the image (rapidly)

Good in the other two, though - a fine noise grain, nothing objectionable at all.
Click to expand...


i'll check with splash..

BTW- i have another annoying thing : i know that 24p is strobby by itself.
but on most of the shots it seem strobier than 24p. especially when you watch vehicles, and movements.. it looks more like an effect than natural 24p.
how can i minimize this enhanced effect? is it avoiding certain ISO? shutter (i haven't shot lower than 24 or above 250)? aparture ?
i hate it when it's SO strobby. film doesn't look like that.

help...
 
roei z said:
i'll check with splash..
BTW- i have another annoying thing : i know that 24p is strobby by itself.
but on most of the shots it seem strobier than 24p. especially when you watch vehicles, and movements.. it looks more like an effect than natural 24p.
how can i minimize this enhanced effect? is it avoiding certain ISO? shutter (i haven't shot lower than 24 or above 250)? aparture ?
i hate it when it's SO strobby. film doesn't look like that.
Click to expand...
24P footage is very sensitive to shutter speeds used. Ideally, you need 180-degree shutter (1/48 s) or the closest one to it (1/50).
 
svecher said:
24P footage is very sensitive to shutter speeds used. Ideally, you need 180-degree shutter (1/48 s) or the closest one to it (1/50).
Click to expand...

thanks :)
so if we don't have 1/48, 1/50 is an iron rule for my needs?.. i actually remember something about that... no other things to be careful of?
i hope that 1/50 will resolve this. why this cam don't have 1/48? it's only on camcorders and pro cinema cams?
 
I'm starting to wonder if my monitor is well calibrated, but many GH2 video samples I'm seeing seems to have low dynamic range compared to the 7D for instance. Am I the only one to think that? That worry me.. Just hopping it's a common settings problem.
 
fjolliton said:
I'm starting to wonder if my monitor is well calibrated, but many GH2 video samples I'm seeing seems to have low dynamic range compared to the 7D for instance. Am I the only one to think that? That worry me.. Just hopping it's a common settings problem.
Click to expand...

This for me is the only question mark where I would like to get some test. For me compared to photography this is where video lack a lot. More so that after we got 24p, shallow dof this is the last variable that contribute to the film look.
 
Well from the clips I've seen on my calibrated Eizo, the GH2 seems to have amazing dynamic range, especially on this clip as linked by Hunter http://vimeo.com/16464227

I'm a stills shooter using Hassy dig backs, and from what I can see so far, this little Panny seems to have better dynamic range than my mega bucks Hassys :shocked:, okay I'm comparing video to stills but its very interesting all the same.
 
roei z said:
but on most of the shots it seem strobier than 24p. especially when you watch vehicles, and movements.. it looks more like an effect than natural 24p.
how can i minimize this enhanced effect? is it avoiding certain ISO? shutter (i haven't shot lower than 24 or above 250)? aparture ?
i hate it when it's SO strobby. film doesn't look like that.

help...
Click to expand...

The ultimate solution against srtrobiness: 720/50p... ok, ok, you want 24p, right?

Try with a 25th is that is possible a 30th if this is the closest you get get.
Compare it to the 50th and see what you like better.
 
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