GH4 4K Panasonic video camera, official topic

MarcioK

http://www.bestmirrorlesscamerareviews.com/2014/03/04/hands-on-with-the-panasonic-gh4-leica-15mm-and-nocticron-425mm-at-the-tps/

This hands-on have one interesting thing - there are Dropbox links with original MOV files from the GH4 (albeit it is not a produced movie, only a hands-on in the The Photographic Show in Birmingham).

https://www.dropbox.com/sh/q2j2ju87chc5z0t/OjnoVGA4X8

andrevanberlo

Didn't see this here before so thought I'd post it:

lolodigital

@andreanberlo I doubt that it comes from a gh4 shot, and it doesn't realy convince me about the image quality... Whites apparently realy like to be burned ;)

karl

The skater video, if it was made without "doing 10 takes and choosing the one out of ten where the focusing coincidently worked fine", was kind of impressive. If the continous focus works as swift as this video could suggest, that would be a very good reason for me to upgrade for underwater videography (where manual focusing is not a good option).

I also downloaded two of the .MOV files from dropbox that are said to be right off the GH4 (which seems plausible from what the files contain), and checked that both avidemux 2.6.7 (for compressed domain rough cutting) and kdenlive can work with those files, plus that I can replay them on my laptop, and all of that worked just fine.

That's both very good news for me, getting closer to a "buy" decision.. ;-)

karl

For the fun of it, here's the details that "ffprobe" tells us about one file from the dropbox files linked above:

  Metadata:
    major_brand     : qt  
    minor_version   : 537986816
    compatible_brands: qt  pana
    creation_time   : 2014-03-02 13:56:06
  Duration: 00:00:17.28, start: 0.000000, bitrate: 94862 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 3840x2160 [SAR 1:1 DAR 16:9], 93250 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc (default)
    Metadata:
      creation_time   : 2014-03-02 13:56:06
      timecode        : 00:00:00:00
    Stream #0:1(und): Audio: pcm_s16be (twos / 0x736F7774), 48000 Hz, 2 channels, s16, 1536 kb/s (default)
    Metadata:
      creation_time   : 2014-03-02 13:56:06
      timecode        : 00:00:00:00
    Stream #0:2(und): Data: none (tmcd / 0x64636D74), 0 kb/s (default)
    Metadata:
      creation_time   : 2014-03-02 13:56:06
      timecode        : 00:00:00:00
    "streams": [
... see attached file for more details

The order of frame types in the video is I-B-B-P-B-B-P-B-B-P-B-B-I.

caveport

I just downloaded the sample clip of the girl's face and converted using Quicktime 7 to Avid DNxHD 185 10bit PAL. I then imported into Avid Symphony 6.5.2 and played around with colour correction to see how it looked. I have a Flanders Scientific monitor and a Sony 42" pro screen for grading.

Good news for all you colour grading types. It looked great. I isolated RGB channels looking for blockiness in the colour and pushed the grades to ridiculous extremes. No artefacts, no blockiness, just a slight amount of fine grained noise in some shadow areas. I can't make any comment about 4K performance but for down converting to HD it looks really really good. I can't wait to see some samples shot with proper lighting instead of the trade show lighting that was on this clip.

Also I suspect that this is shot to the onboard card in 4:2:0 8 bit. If 4:2:2 10 bit looks better than this then I will be one happy Panasonic customer.

MarcioK

@caveport Since it was a photo show and the reviewer said that only had a few minutes with the camera, I guess that it is the internal 4:2:0 recorded in a SD card indeed.

AdamT

@caveport Thanks for the report -- sounds like Panasonic has a winner.

rNeil

@caveport

good to see your comments vis a vis grading. What jumped out at me from just watching that clip above was the absolute lack of "plasticene" or red/magenta blooming. That skin looked like skin with normal human texture to it. Yea, the color balance was crap but still it was skin.

caveport

@rNeil The colour balance was due to two different light sources. Blue on the left, yellow on the right. I did a heavy secondary correction (during my lunch break) to minimise the yellow cast and another secondary to lift the colour in the eyes. Used DaVinci Resolve and had no sizzling edges or other artefacts. I graded using the full 4K file download and rendered out to ProRes HQ 4:2:2. It looked very clean even though I would not consider it a good skin tone. At this early stage I am very happy with how the image holds up under heavy grading, and this is 8bit 4:2:0!!! Panasonic have really done a nice job with the compression on this camera.

Eno

Thank you for the link to original samples MarcioK. Although the samples are shot from the hand, the AF is hunting a little and the DOF is extremely shallow, the quality is very good, I'm satisfied.

plasmasmp

I was going into it thinking the 4k would be unusable at 100mb, but those samples at native 4k are impressive. Sure there isn't a whole lot of motion/contrast to stress the codec, but the sensor grain is clearly visible at 4k and not smeared - similar to the prores of the BMCC4K but at a much lower bitrate. Certainly not a repeat of the unhacked GH2 where I thought the GH4 would be starved for bandwidth.

Matt

Anyone know whether the GH4 has an oversized sensor like the GH2? "Multi aspect ratio" sensor is what they called it I think...

caveport

Did some more testing in Resolve. I can see the compression macro blocks. I will try to attach some screen grabs to show the artefacts when zoomed at maximum in the Resolve viewer. I think the 4K is very good and will down convert to HD with impressive results. On a 4K screen heavy grading may make some compression artefacts visible.

Tron

The image sharpness looks really impressive. For proper 4K encoding they probably should have gone with at least 200Mbps though. I thought I heard somewhere that the cinema 4K mode will be able to do 200Mbps??

Tomaso

@Tron From the specs in the pdf posted earlier and the specs on page 1 of this post it is only 1920x1080 mov/mp4 All-I in all frequensies that can be recorded in 200 Mbps

AdamT

In one of the interview videos (Nick's, I think) a Panasonic rep. says that the camera's processor was the bottleneck that limited 4K to 100 Mbs. The hardware just couldn't process all that data fast enough.

SuperSet

Bummed that the display is still going to dim and disappear after some time. It looks like the timer is now longer though (30s to dim, 60s to disappear). Will have to see how this affects operation.

Tron

I'm surprised they haven't instituted pixel shift technology for the display overlays if burn-in is what they are primarily trying to avoid. My Panasonic plasma from 2005 has pixel shift and has never had any issues with burn-in. 60 seconds is a lot more manageable then the current 10 seconds but it would be nice not to have to hit a function button to get them back during a shot.

dannydale

In the Personal View/Driftwood interview with Mark Baber, at 19:06 Mark states that the screen info will fade from white to gray and stay on for 5 minutes while recording video before turning off...did anyone else catch that? He also said that it will dim after :30 seconds and stay on for another :30 before turning off...maybe this 1-minute cycle only happens when camera is in standby?

Tomaso

@dannydale Yes this was the answer to that qustion. He was also saying that by pressning any KEY the info display comes back.

Aria

I wonder if they will do a firmware update to bring this Display Overlay from the GH4 to the GH3? It sounds like something they could port over.

andrew00

I'm really interested in the GH4. I often take fashion-y pics, aka with strobes and stuff, and always like the idea of being able to take video that 'look' the same.

GH4 seems like it's going to get nice and close. Nothing needs to change if the setup is continuous, just switch between the two.

I'm also interested in how the 4K will look if it's modified a bit. I'm also a fan of using a Black Pro Mist and am curious about the SLR Magic Anamorphic. Wondering if the two of them + a GH4 could be nice - footage that's pretty nice and natural looking with an abundance of resolution could down sample nicely to 2k?

heradicattor

Anyone mirrored the original file to download? The Dropbox account is disabled :(

Vitaliy_Kiselev

Anyone mirrored the original file to download? The Dropbox account is disabled :(

I am sure that many downloaded it. Just need to share files using better method :-)

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