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

Barry_Green said:
If you want your footage to look like a film camera shot it, you want to use 1/120 shutter on 60fps that's intended to play back at 24fps. That's the speed that will match the exposure (and motion blur) that a film camera would.
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I think the point of confusion on this issue is that the phrase "look like a film camera shot it" means a film camera running at 60fps, with a 180 shutter and thus a 1/120th second recording time.

The other method, I think, was an attempt to run at 60fps, and then have it play back at 24fps with the motion blur as if it had been shoot at 24 fps (and all of reality was slower.)

Or put another way, a high speed film camera cuts down on motion blur because the shutter moves faster (while still being 180 degrees).

Kholi said:
I don't know just yet if there's a recording time limit, I'll have to let it run for a while to see. Coming soon.
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I saw on one of the Panasonic spec sheets, once, that the "max recording time" was 120 minutes-- this was a claim of the batteries performance, rather than a built in limit to the camera. I believe that if you use the battery adapter and run the camera from wall current that it will record as long as you have card capacity.

Peter J. DeCrescenzo said:
I recently purchased a Kingston 8GB SDHC Class 6 memory card from Amazon.com to use when we test Hunter's GH1 soon:
I won't know for sure until we try it if this card is appropriate for use with the GH1, especially its full-HD 1080p24 AVCHD recording mode.
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17Mbps is 2.125 MBps. Class 6 means the minimum sustained transfer rate the card claims to be capable of is 6 MBps so you should only be using 1/3 of the peak bandwidth of the card.

A Class 4 card should be more than adequate, but given that there isn't really a price premium for Class 6 I don't think there's any reason not to use them.

Kholi said:
How is this possible?Anyone know what's going on? Theories?
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I believe what we're seeing with the lower bitrates is the effect of variable bitrates (the "VBR" in the specs). If the camera's sitting there recording a static scene, it should take significantly less data to record each frame, and in fact probably most of the data will be the periodic complete keyframes rather than interframe deltas.

So, "17Mbps" is probably a guide, and in actual use might range between 15 and 25Mbps depending on what is needed by the scene in question-- and what's been going on previously.

The camera probably has a fairly large buffer -- probably 48MB going by the burst shooting mode specs-- which means it can probably hold around 10 or more frames in memory at a time for analysis... and to some extent allocate the bandwidth to the frames that need it the most.

Might be worth shooting 2 30 second clips, one with the camera facing a blank wall or simple static scene, and the other outside panning the camera around constantly... and then look at the file sizes and see if they are different. I would be surprised if they are nearly the same. If they are then the compression is targeting a constant bitrate, but if not then its letting the differences between the frames determine how much of its bitrate it uses to store them.
 
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hunter richards said:
Just got mine! I tried the live composite out put and it does spit out a live image through the a/v cable.

The only issue is 1. You have to have the LCD flipped on, 2. It stops spiiting out a live image once you press record. So its a no go for having a directors monitor.

Maybe kholi can try the test with the hdmi again? You open the LCD, press display, and then hold down the Trash button for 10 seconds about- the screen flashes for a second and then you get a live image.
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That's great news, Hunter.

Just curious: Does the "LVF/LCD" button have any affect on live composite video out when recording?
 
Peter- The live feed only happens when you have the LCD on, if the EVF is on it wont work- and as soon as you hit record the life feed stops.
 
Barry_Green said:
Kholi, I'm using Nero to play the files back; you can tell it to display additional data such as bitrate and frame rate. On the 0040.mts file, it drops as low as 6 megabits in places.
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Try using KM Player...

This may not play the video Perfectly but will show you all the essential video info.

Hope it will help you....

General :
Complete name : 00024.MTS
Format : BDAV
Format/Info : BluRay Video
File size : 18.1 MiB
Duration : 9s 974ms
Overall bit rate : 15.2 Mbps
Maximum Overall bit rate : 18.0 Mbps

Video :
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.0
Format settings, CABAC : No
Format settings, ReFrames : 2 frames
Width : 1920 pixels
Height : 1080 pixels
Display aspect ratio : 16/9
Frame rate : 29.970 fps
Standard : NTSC
Colorimetry : 4:2:0
Scan type : Interlaced
Scan order : Top Field First

Audio :
Format : AC-3
Format/Info : Audio Coding 3
Duration : 9s 974ms
Bit rate mode : Constant
Bit rate : 192 Kbps
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 48.0 KHz
 
the D90 captures between 7-25Mbps in motion so 9Mbps doesn't sound strange for a far more efficient intraframe codec
 
Regarding Philip Bloom's red GH-1 on page 24 of this thread ...

Does it come with a microphone, or is that something you have to order separately?

I was going to order the Zoom H4n, but maybe I should wait until Kholi, Hunter, and Philip report back on sound quality???

Then again, all my mics are XLR.
 
So just to be clear...there is only composite out and not component? Kholi did you get to try the test Hunter suggested with HDMI?
 
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