The Panasonic G1HD | GH-1 Video Mode : A Real Video Mode

stephenvv said:
That's a guy fumbling and banging the camera making exposure, shutter and who knows what other changes on handheld telephoto shot - not the exposure change most people who do in a keeper shot.
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Yea, the codec falls apart big time with the exposure change but it would get discarded by a reality editor for the exposure change and not the codec breaking up.

Kholi really needs to make a field dvd for proper run n' gunning wth this camera so poeple will know how to properly handle it.

Kholi, I'd pay $49.95 for it if you have the time to make it :)
 
Kholi said:
How do you get rid of aliasing? Please share!
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By dealt with I mean knowing it is there and using in front of and in post filter, camera exposure (it's always worse on bright, sharp focus edges), short DOF etc.

I've seen plenty of beautiful 1080p and plenty of aliasing from both cams, so to me it's just a matter of working around it. But it's also a personal thing - the large jaggies bother you but I never notice them on a first pas.

The finer ones on the Mark II cause motion waves and wiggles in the shot that draw your eye to them bother me much more.
 
from cnet- Panasonic has set the RRP for the GH1 at AU$3299, which includes the new Lumix G VARIO HD 14-140mm lens. The camera will be released in Australia in late May.
 
Kholi said:
Quite literally.

Only other thing I did and compared was turning frame blending on and off. Someone said that without Frame Blending it on it was exactly like 24P to him. I liked the Frame Blending on, it looked silky smooth but still 24P to me.

The sound was still in sync as well, from camera.
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I can confirm that this also works like a charm in PPro CS3. I dropped 60p footage straight from camera on a 24p timeline and stepped through it. Every frame looks like a unique, solid frame. No weird stuff going on. In motion it looks right. Wow.
 
holyzoo said:
Can ya see the destruction? Or no? Can the average person see it?
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This clip was a real eye opener. I thought all this time people were picking apart the codec, with reasonable footage. But its clearly not the case.

What's happening there is really sharp changes in the exposure. Such that in just a few frames it goes up or down several stops. That means every single pixel in those frames has changed-- an impossible compression issue.

No camera can handle a 49 MBps (that's megabyte, not megabit) datastream. IF there are no similarities frame to frame, that's what you end up with.

In other words, there isn't an issue of compression breaking, there's an issue of the source video breaking because of a faulty iris or faulty camera operator.

If this is what people are talking about, then its clear to me that 17Mbps is plenty of bandwidth and all the talk about 1080 being bad is way premature.

Kholi said:
That's fine, I'm saying that's how EASILY it breaks.
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That's not a compressor breaking easily. That's a compressor breaking in close to the worst case scenario. You need a reasonably steady exposure-- a cloud moving in front of the sun is fine, that's rather slow compared to these shifts.

Every compressor will break under those conditions due to the nature of the information and the nature of the way compressors work.

you should either just deal with the ugly compression if you ever have a shot like that, grab another camera or avoid it altogether.
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Please enlighten me on this film technique where exposure is rapidly ramped up and down over a few frames. It seems very odd, but at any rate, if you want such an effect better to do it in post in uncompressed, or close to it.

Or you could just use 720/60P.
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If you ramp exposure like that in 720/60p, the compression will break down just as bad, probably worse.

Maybe the exposure issue is due to some bug in the code when the camera is in 1080 mode and that's why you're not seeing it in 720.... that's quite possible. But its not intrinsic to the compressor or to 1080.
 
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LizaWitz said:
Please enlighten me on this film technique where exposure is rapidly ramped up and down over a few frames. It seems very odd, but at any rate, if you want such an effect better to do it in post in uncompressed, or close to it.
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Steadicam work. From outside to inside or viceversa. It's quite common.

If you ramp exposure like that in 720/60p, the compression will break down just as bad, probably worse.
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You're wrong.
Maybe the exposure issue is due to some bug in the code when the camera is in 1080 mode and that's why you're not seeing it in 720.... that's quite possible. But its not intrinsic to the compressor or to 1080.
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I'm off the subject. When you get the camera in your hands, judge for yourself.

I feel the only other things I can learn about this vehicle is to actually drive it. AKA I'm ready to shoot something serious with it.

You guys can check the compression in raw format when you get it, and formulate your own opinions. I've said my piece. Sorry if it's not what you want to hear/read.

I'd be useless if I didn't post what I find appealing AND unappealing about the camera.

But I bet Philip and Hunter are plenty pleased with the 1080 format. So there you go. One person out of a few, not such bad odds!
 
Kholi said:
Steadicam work. From outside to inside or viceversa. It's quite common.
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Nope, not at all. This is clearly an iris problem, or someone pushing a dial to switch the exposure. This is not like going from an interior to an exterior, which, even if you were running flat out would be a much smoother transition-- and much more compressible.

You're wrong.
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I'm not sure if a two word "rebuttal" deserves further explanation, but for the others who might be reading this, a 60fps video stream has a bit over 1/3 the time to encode the video as a 24fps stream, and while the resolution is lower, the effective required bitrate is still over the top.

Sorry if it's not what you want to hear/read.
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Actually this is great news. A faulty iris means that it is not a fundamental defect in the camera or the way its doing its compression. IF your footage looks like this, then when the exposure issue is fixed, the compression issue will go away.
 
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Hey Kholi - or anyone else with an NTSC GH1 -
Might not be easy to coordinate, but if you end up in the same city with Phil, I'd love to see 1080p/60i (after pulldown is removed) compared with 1080p/50i (slowed down to 24fps), to see if there's a noticeable difference in quality.
 
hey Kholi:
What contax lenses are you planing to use with the camera? Are there any fast contax lenses available wider than 25mm? 25mm on this camera isn't very wide at all. What adapter are u using? I wish the sensor was a little bit larger because primes that are fast and <25mm are pretty expensive...
 
cordvision: .. WTF, I thought for a second a bug was running on my screen, until I realized it was your signature..
 
More footage is on the way. I have uploaded a rar file of the private folder on my GH1 so the FCP users can have a better time ingesting the stuff. 7 pieces of footage...all at night...Just waiting for Daniel L to give me the thumbs up to post the link. ALL 720. Again no editing or transcoding or whatever.
I'll echo Kholi's sentiment - I think 720 on this cam is the way to go...it really is amazing what this little cam can do...
BTW had a close call with the neighbourhood kids, fingers and the lens so the footage was shot through a cheap ass (40 bucks) lens protector :)
Cheers.
Sam.
 
must be a friendly neighborhood. In my neighborhood a close call means you come home alive without your GH1

hanging to see some raw footage!
 
squig said:
must be a friendly neighborhood. In my neighborhood a close call means you come home alive without your GH1

hanging to see some raw footage!
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Hehehe...yeah not that kind of close call...but a mean fingers on the lens, man!!!
I am just thinking if I was shooting that stuff with the HVX it would be dark, dark, dark (I don't have the 200A btw)... but with the GH1, although open wide and at 1600, it does a pretty respectable job...Steve Castle's footage gives you a sweet taster.
 
LizaWitz said:
I'm not sure if a two word "rebuttal" deserves further explanation, but for the others who might be reading this, a 60fps video stream has a bit over 1/3 the time to encode the video as a 24fps stream, and while the resolution is lower, the effective required bitrate is still over the top.
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I think that what might explain why the 60p footage is looking better, compression-wise, to some is that the 24p is being encoded as a 60i signal. It's not a 24p stream with a pulldown flag; it's a hard-coded 60i stream. As Barry noted, perhaps interlaced footage is harder to compress than progressive footage, and the 60i is at a much higher resolution. So in fact, the 1080i60 could be delivering more information that's less easy to compress than the 720p60. Just a thought.

Although I don't generally disagree with your points in your previous post, I just wanted to mention that non-interframe codecs, such as DV, AVC-Intra, and MJPEG, would not suffer from compression difficulties if the image rapidly changed from frame to frame.
 
LizaWitz said:
If you ramp exposure like that in 720/60p, the compression will break down just as bad, probably worse.
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Kholi said:
You're wrong.
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I have to agree with A.L. here, who makes a good point.

As I posted in the other thread, you can clearly see motion compression faults with the 720p60. It's stands to reason that the the rapid exposure change compression artifacts are at least equal in the 720 mode. Even if in 720 they don't seem as apparent when viewed at a normal playback speed because the images don't hang on the screen as long with the lack of 3:2. This is easy to test and can be determined conclusively.

I.

Illya Friedman
Hot Rod Cameras
 
If the mjpeg is averaging 26Mbps I'd be inclined to use that and do the 30p to 24p conversion. Surely panasonic could do a firmware update with 24p mjpeg at around 40Mbps which would look pretty good.

OK I'm done measurebating
 
im assuming what the gh1 needs in compression is a better processor itcant just befixed by firmware.

it may not be able to encode avchd as much as it can. but for what it gives, its good enough.
 
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