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Panasonic DMC-GH2 announced at Photokina 2010


Peter J DeCrescenzo

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FYI: The GH2's CMOS rolling shutter "skew" artifact performance is shown to be as good or better than the GH1 (hacked or not). In some operating modes, the GH2's skew performance is significantly better than the GH1.

 

Verified by 3 different testers commenting in this thread (including correctly-done test videos):

http://www.dvxuser.com/V6/showthread.php?232220-Gh2-skew

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Hi Tim: Sorry, but I don't have easy access to 16mm lenses or appropriate m43 lens mount adapters, regrets.

 

I've seen discussions on DVXuser & elsewhere where folks claim to have used these with the GH2's Extra Tele Conversion mode. Apparently many lenses designed for 2/3" video or 16mm film cams work w/o vignetting, as will some C-mount lenses designed for 1/2" video cams.

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Hmm. I have a moderately usable 1/2"-format broadcast zoom lens that might be an interesting fit

 

What's this problem with the HDMI?

 

Edit - this problem with the HDMI is that it's interlaced up to 60i, at least on NTSC models. We sort of knew this. Notwithstanding the elaborate conspiracy theories over on DVX User, I suspect it's been done that way because 60Hz formats are by far the most widely supported and avoid dropping unsuspecting users into EDID hell with their HDMI devices.

 

As I've said before is entirely feasible to write recorder software to decimate frames back out of this, but the time involved in doing so is considerable and would require R&D funding.

 

P

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Here are some nice little GH2 gifts for the holidays:

 

DP Emmanuel Pampuri used a GH2 to shoot this behind-the-scenes footage during a fashion shoot in France:

http://vimeo.com/18155086

 

Vimeo members can download a higher-quality (less-compressed) 425MB version of the video from the Vimeo page.

 

Also:

 

DP Hunter Richards has posted a write-up on DVXuser (including photos & tech details) describing his using a GH2 on a corporate shoot:

http://www.dvxuser.c...the-application)

 

Cheers.

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I've posted a series of ~10-sec. video clips showing grayscale & MacBeth charts depicting each of my GH2's so-called "Film Modes" (color profiles). There are ten clips, numbered 20-29.

 

In addition to the highly-compressed versions for viewing in your web browser, Vimeo members (free) can download the camera-original versions of the clips. I rewrapped the camera-original AVCHD .MTS files to QuickTime .MOV file without recompression so more people can use them.

 

I hope these are useful. Compare, contrast, discuss. No conclusions from me yet. Cheers.

 

Tech details are on the Vimeo pages, but to summarize:

 

Exposure was set using the GH2's "REC HIGHLIGHT" feature which has been shown to indicate white clipping at 100 IRE. The whites chips & cards on the charts where set _once_ (and once only) at or just slightly below 100 IRE while the camera was in STANDARD Film Mode. ISO was set at 320, and the Lumix 20mm lens was set at f2.0. Shutter 1/60th.

 

1080p24 "24H" progressive. Full manual mode, including the GH2's "iDynamic" & "iResolution" both OFF.

 

The camera was white balanced while in STANDARD Film Mode. Once set, this one WB setting was used for all the clips. Lighting was 4 tungsten bulbs through diffusion.

 

In these clips, all of the Film Mode sub-settings (contrast, sharpness, color & noise reduction) have been set to their lowest values (-2). These same -2 values were used for all the tests.

 

Any changes in exposure or color among these video clips is the result from switching among the GH2's Film Modes. No other changes were made to the camera settings between clips.

 

Standard:

http://vimeo.com/18203359

 

Cinema:

http://vimeo.com/18203656

 

Dynamic:

http://vimeo.com/18203811

 

Smooth:

http://vimeo.com/18203954

 

Nature:

http://vimeo.com/18204031

 

Nostalgic:

http://vimeo.com/18204186

 

Vibrant:

http://vimeo.com/18204311

 

Standard B&W:

http://vimeo.com/18204424

 

Dynamic B&W:

http://vimeo.com/18204527

 

Smooth B&W:

http://vimeo.com/18204625

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FYI: Vitaliy Kiselev, the Russian programmer who hacked the GH1, has recently hacked the GH2.

 

For information about how to download and use Vitaliy's free software, refer to his website:

http://www.personal-view.com/talks/discussion/414/ptool-3.61d-topic

 

I've installed the hacked firmware on my GH2 and it seems to be "working". At least, I haven't experienced any crashes or deal-breaking issues. There are some known quirks, as discussed on Vitaliy's website and elsewhere (such as the DVXuser GH2 forum). YMMV.

 

I posted a couple of brief hacked video clips shot at 1080p24 AVCHD @ 42 mbits/sec (vs. factory-standard @ 24 mb/s) up on Vimeo, and you can also download the camera-original .MTS files to view them w/o Vimeo's encoding. See:

http://vimeo.com/26793783

http://vimeo.com/26793435

 

Cheers.

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Vitaliy, Chris Brandin & their international testing team have created a new version (3.62d) of Vitaliy's firmware hack for the GH2 which enables further video quality improvements. See:

http://www.personal-...ol-v3.62d-topic

 

I haven't completed my informal tests yet, but what I'm seeing -- or what I think I'm seeing ;-) -- is fewer compression artifacts and improved detail in the shadows. Others report similar results, but as always: YMMV.

 

Increasing the bitrate to 32 megabits/sec or more appears to address the relatively small amount of compression artifacts ("mud") sometimes visible in standard GH2 high-motion video. A standard GH2 is much better than the stock GH1 was in this regard, but all cameras benefit from throwing more bits at the challenge of recording high-motion video.

 

The current hack software fixes an issue in the previous version which resulted in the first few frames of >32 megabit/s clips with extreme compression artifacts.

 

Importantly, the new hack allows you to select an overall preference for the GH2's codec ("Auto-Quantizer"): Should the codec use the "extra" datarate bits to record motion with fewer artifacts, or should it use the extra bits to record details (especially in low-lit areas) with fewer artifacts. You can preset this preference on a scale from 0 ("all to motion") to 4 ("all to details"). I'm currently testing "#3 Most to details".

 

I'm hopeful a combination of bitrate, AQ and perhaps other hack settings can result in GH2 video that is essentially mud-free, has fewer gradient banding artifacts, and has improved detail in shadows. More to come ...

 

P.S.: Phil: Sorry, no 25p.

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  • 3 months later...
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Just an FYI:

 

Late yesterday Panasonic released a free new firmware update which adds useful features to their GH2 camera:

http://panasonic.jp/...fts/index2.html

Perhaps the most important new features are 1080p30 and 1080p25 AVCHD recording modes at 24 megabits/sec. Previously the GH2's top-quality AVCHD modes were 1080p24 at 24 mbs or 720p60 (or 720p50 PAL) at 17 mbs. The only 30p mode was a low-quality MJPEG mode, and as discussed previously there was no 25p mode.

One of my clients records bi-weekly studio sessions for broadcast using his two Sony camcorders in 1080p30 mode. Until now, we haven't been able to use my GH2 as camera #3 because it didn't support 1080p30.

Some of the improvements only affect the GH2's still photography mode or only its video mode, but not both.

Panasonic's descriptions of the firmware improvements are a bit cryptic (Japanese translated into English). Item #1 is the new 1080p30 / 1080p25 mode.:

  • Added a video mode [HIGH BIT RATE] which is suitable for editing video recorded at high bit rate(24Mbps).
  • Added a function [POWER ZOOM LENS] when using power zoom lens.
    ([DISP FOCAL LENGTH], [sTEP ZOOM], [ZOOM RESUME], [ZOOM SPEED], [ZOOM RING]*)
  • Full area enlargement of AF area setting.
  • Improved in the speed of consecutive shooting when shot with auto bracket.
  • Increased number of recordable images in consecutive shooting.
  • [EX.TELE CONV. (Extra Tele Conversion)] can be set ON/OFF separately in photo or video recording.
  • More accurate light adjustment of built-in flash.
  • Improved in the AF performance in video recording.
  • Synchronization of alarm volume for low battery with [bEEP VOLUME].
  • Added a function [HALF PRESS RELEASE].
  • Improved NR (Noise Reduction) in high sensitivity shooting.
  • Added a function [TOUCH SCREEN] which is ON/OFF control of touch-screen.

I haven't updated my camera yet. I'll wait at least a few days until I see more reports online of others having done so successfully.

 

#8 ("Improved in the AF performance in video") might come in handy if it works well. Currently, AF in video mode is fairly slow.

 

It'll be interesting to see if #11 ("Improved Noise Reduction in high sensitivity [high ISO] shooting") actually works & looks good.

Vitaliy Kiselev (the Russian programmer who successfully hacked previous GH1 & GH2 firmwares) expects to have the new firmware hacked "soon", but that could mean in a few weeks or many, many weeks depending on how much Panasonic has changed the structure of the new firmware code compared to the previous version. Assuming he hacks the new firmware, all of the goodies he previously brought to the GH2 -- especially high-quality, high bit-rate (up to 200 mbs!) AVCHD recording in all modes -- should be possible with the new firmware, too. For info about the current hack (not based on yesterday's new firmware), see:

http://www.personal-...ack-development

Working with Panasonic's new firmware, it's very likely Vitaliy will finally be able to enable 1080p25 AVCHD PAL recording for _all_ GH2 users. Panasonic's new firmware only enables 1080p25 for users of the PAL version of the GH2, but Vitaly will probably be able to make it available for owners of the NTSC version of the cam, too. (The current version of his hacked firmware already allows NTSC GH2 cams to record 1080i50). Stay tuned.

Hopefully this will all turn out to be a nice little Xmas present from Panasonic!

If you're new to the GH2, or are wondering what it was capable of before the new firmware, here's a beautiful recent example shot by "vesubio":

http://vimeo.com/33025136

Cheers.

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  • 3 weeks later...
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Philip Bloom recently posted part 1 of his admittedly unscientific "Xmas 2011" camera shootout, pitting a hacked GH2 against some pretty stiff competition, including the Sony F3 & FS100, Canon C300 & 7D, and others.

 

The bottom line is the GH2 comes out of this shootout with its head held high, um, er, well, with at least its flash hot shoe held high, or something! :-)

 

See Phil's blog post for details, and also the video of the shootout:

http://philipbloom.n...stmas-shootout/

 

http://vimeo.com/34279033

 

Cheers, and as always: YMMV!

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Philip Bloom recently posted part 1 of his admittedly unscientific "Xmas 2011" camera shootout...

 

 

I have a real problem with this "unscientific" comparison. I mean, if you're going to go through the trouble of assembling your blokes and a bunch of different cameras, why not do it in a heated garage with a tungsten light source and a real test chart?

 

This video doesn't prove much, and it will unfairly influence purchasing decisions.

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Hi Tim: I think I see your point, but Phil goes a long way in "qualifying" (as in down-playing the final-word aspect of) his informal test.

 

My feeling is, which is worse: Someone buying a $650 GH2 or a >$4K camcorder after watching Phil's shootout?

 

If someone actually needs most of the capabilities of a >$4K camcorder for their productions, God help them if they primarily base their purchase/rental decision on Phil's shootout. Buyer beware, YMMV, etc., etc.

 

And of course, some of the much more expensive camcorders in Phil's shootout have obvious advantages in specific cases (such as XLR audio connectors, headphone jacks, 10-bit 4:2:2 live outputs, better dynamic range, etc.). As always, use whatever tool which best matches the task at hand & the client's budget.

 

Same as ever, right?

 

Cheers!

Edited by Peter J DeCrescenzo
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I think Bloom wisely avoids the politics that come with a "scientific" evaluation test where everyone chimes in with how it was done wrongly if they don't like the results. The flipside with these sorts of "real world" tests, which are completely valid, is that many image characteristics are harder to spot, thus only allowing general impressions to be formed.

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FYI:

 

Vitaliy Kiselev has released a new version of his firmware modification utility software, PTool v3.64d, compatible with Panasonic's current firmwares for the GH2 & GF2:

http://www.personal-...ol-v3.64d-topic

New settings files for use with PTool are posted here as they become available:

http://www.personal-...es-in-one-place

On the GH2 the modified firmware reportedly makes possible higher data-rates for all video modes, including 1080p AVCHD @ 24p, 25p, 30p and more. I haven't tested it yet myself, but plan to soon. YMMV.

For info about Panasonic's current GH2 v1.1 firmware refer to their website and my post above #:

http://panasonic.jp/...fts/index2.html

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On 3/28/12 Vitaliy released version 3.65d of his PTool firmware hack:

http://www.personal-view.com/talks/discussion/2712/ptool-v3.65d-topic

 

PTool version history here:

http://www.gh1-hack.info/wiki/VersionHistory

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  • 2 weeks later...

But Hitler missed all the real problems, like shooting under non-flicker-free lighting in 50Hz locations at 24p, which causes enormous hum bar style artifacts.

 

P

 

Have you used the 1/50th-1/100th shutter in order to keep it under control?

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