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Peter J DeCrescenzo

Panasonic GH1 DSLR 1080p24 HD 12MP 17.3x13mm sensor

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Those DSLR videos produce a lot of aliasing artifacts. Who wants to shoot a subject wearing a shirt with horizontal pin stripes and it ends up looking like he was wearing a shirt with vertical stripes?

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Yes, Hell has frozen over: After all my whining, I decided to buy a GH1 anyway. :-)

 

I needed a smallish "DSLR" for personal photo-taking, and this one also records occasionally-useful HD-like video, too. As I suspected more than a year ago, the GH1 is a very fun & versatile cam despite its limitations.

 

Read all about it here:

http://www.dvxuser.com/V6/showthread.php?t=202716

 

Meanwhile, the "GH2" (or whatever it will be called) is generally expected to be available by the Photokina expo this Sept. or soon thereafter. Stay tuned.

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FYI: In the interest of completeness, and in case you're one of the last people on Earth who hasn't already heard about the firmware hack project for the GH1:

http://www.dvxuser.c...ad.php?t=206788

http://www.eoshd.com...e-Panasonic-GH1

http://www.dvxuser.c...ad.php?t=213082

 

More than a quarter million people have viewed at least one page of the >234 page original thread on DVXuser!

 

Anyway, folks like Andrew Reid (of EOS-HD.com) are already doing some nice work using what is essentially currently pre-alpha version modified firmware created by the mysterious "tester13".

 

Nerds like tester13 sure are cool sometimes!

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Nerds like tester13 sure are cool sometimes!

 

I wouldn't call tester13 a nerd, I'd call him a brilliant computer programmer. What he has done with the GH1 firmware, opening it up, figuring out ways to modify it to extract higher quality images and video is simply mind boggling to anyone who knows programming.

 

As he points out when he defends Panasonic, there are dozens of people in different departments at Panasonic who develop these cameras, and each is an expert in their particular area, be it sensor design, software, firmware, etc. And some parts of the camera are capable of much greater image quality than the sum of the parts. What tester13 has done is taken all those parts, and figured out how to make them work together and interact, to obtain the best out of the whole package. That is simply amazing.

 

Best,

-Tim

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Do we have any idea if this thing has better aliasing performance than the Canon stuff?

 

P

 

Phil,

 

I'm still a little hesitant to throw the firmware on my GH1. Been trying to sort through the hundreds of pages of posts on the threads over at DVXuser. From what I am gathering, from reading the posts and looking at the frame grabs and video footage, I think the aliasing performance is on par with the Canon stuff or maybe a bit better.

 

I decided to go with the GH1 over one of the Canons because of the ease of using my Cine lenses with the GH1 (w/Hot Rod adapter). I wasn't crazy about taking a brand new Canon camera and paying a few thousand more bucks to have someone tear the front off of it and replace it with a PL mount. I also like many of the features on the GH1, like the viewfinder, the focus assist, and the manual "movie" mode. The stock AVCHD codec is kind of crap, but with the firmware hack, that might be up to snuff soon. And if you want to take the time lighting, and setting up your shots carefully, you can work around some of that aliasing issue (but obviously not in a run and gun, documentary setting). I plan on using mine for narrative work, so I hope it will work out well. Time will tell.

 

Best,

-Tim

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Do we have any idea if this thing has better aliasing performance than the Canon stuff?

 

P

 

Phil,

 

I took the plunge and patched my firmware. Wanted to see how it effected the image quality in 1080p AVCHD when in motion.

 

Before I did the patch, I shot a scene with the camera on a tripod with the following settings, then repeated that scene as closely as possible to see the difference.

 

GH1 in Standard Setting

FHD

ISO 100

1/50th second shutter speed

Cooke Speed Panchro 18mm at T 11

 

Here is a compressed version of the clip:

 

http://www.lilfolksproductions.com/BeforePatch.htm

 

I then did the patch with the following settings:

-Native 24p/25p

-Video Buffer - 40000000

-Video Bitrate Adjust - 38000000

-Overall Bitrate Adjust - 40000000

-Limiting Bitrate Adjust - 42000000

 

Then I attempted to shoot the same scene with the same settings:

 

GH1 in Standard Setting

FHD

ISO 100

1/50th second shutter speed

Cooke Speed Panchro 18mm at T 8 (it had gotten darker)

 

Here is a compressed version of the clip:

 

http://www.lilfolksproductions.com/AfterPatch.htm

 

The compressed clips are too small to tell much, but I wanted to post them for reference.

 

I took two frame grabs of each clip, in an attempt to show the difference. To make the frame grabs manageable I had to compress them slightly.

 

Looking at the tree going past, you can see the difference in the following two frame grabs. Also, after the patch there is more detail in the house in the background.

 

Before the Patch:

BeforePatch1a.jpg

 

After the Patch:

AfterPatch1a.jpg

 

And there is more noise in the dark area of the porch post as it goes by (I know there is a technical name for that, but it escapes me at the moment). Also the details of the shingles on the brown roof are clearer after the patch.

 

Before the Patch:

BeforePatch2a.jpg

 

After the Patch:

AfterPatch2a.jpg

 

 

That should give you some idea. The patch allows the camera to shoot 24P natively (23.976 fps) so there is no need for pulldown removal. Also, the bit rate is higher.

 

There have also been changes and improvements in the MJPEG set up with the camera, but since I don't shoot that, I haven't bothered with it.

 

Best,

-Tim

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Do we have any idea if this thing has better aliasing performance than the Canon stuff?

 

P

 

Hi Phil,

 

Here's a clip from some of the MJPEG footage I've been shooting with the GH1. This is foliage, not too dense, but as you know the details in foliage can really tax the whole firmware, compression, output system on the camera.

 

The original footage is 1920 x 1080 at 30P (actually shot squeezed at 1280 x 1080 30P) and the capture bit rate was 73.89 mbits/sec. That's way to big for the web, so I had to compress the footage to make it manageable. This clip is 848 x 480 at 15P and with a bit rate of 11 mbits/sec. So some detail is lost and some blocking is taking place, but it's minimal.

 

The clip is about 10MB so give it time to load, and it is in the Apple MJPEG A codec.

 

What I think demonstrates the improvements the patches create in the firmware is how the foliage comes into focus in the last half of the clip. From blurry to sharp, and in the original, there was no blocking in the foliage when it was out of focus, and it just "naturally" becomes sharper and sharper as it comes into focus.

 

MJPEG clip shot with tester13's patches to the GH1 firmware

 

Best,

-Tim

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FYI: Refer also to Hunter Richards' recent posts concerning the GH1 & the firmware hack:

dvxuser.com/V6/showthread.php?t=213886

dvxuser.com/V6/showthread.php?t=214113

 

I've been having some fun with it, too:

http://www.vimeo.com/12685523

http://www.dvxuser.com/V6/showthread.php?t=214160

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I get the impression that cap would have aliased like crazy on a Canon.

 

Hrmm... I wonder if there's one of these in London I could get hold of. May be shooting some greenscreen tests shortly.

 

P

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Sigh. The firmware hack for the GH1 & GF1 has hit a serious roadblock. Panasonic recently changed the firmware on newly-manufactured GH1 & GF1 cameras.

 

The new firmware appears to exist solely to block use of Vitaliy Kiselev's PTool3 firmware modification utility (AKA the "GH1 firmware hack").

 

Panasonic's new firmware is not yet a public release, and at present end users can't download it. Thus this issue is of primary concern for purchasers of new GH1 & GF1 cameras.

 

See Vitaliy's recent post about this issue here:

http://www.dvxuser.c...ad.php?t=218001

 

This not entirely unexpected turn of events has the side effect of making older GH1 & GF1 cams (ones manufactured at least several weeks ago or earlier) more valuable because they _can_ be updated by PTool3.

 

Vitaliy continues to frequently update & improve his PTool3 software. The most current version of PTool3 is available via the link in the 1st post in this thread:

http://www.dvxuser.c...ad.php?t=206788

 

There's a possibility Vitaliy may be able to program around Panasonic's roadblock. DVXuser members and others are attempting to apply pressure on Panasonic to relent and release GH1 & GF1 cams without the block.

 

In any event, it's widely expected that a _new_ camera model—the so-called "GH2"—will soon be announced by Panasonic no later than the Photokina Expo in Sept.

 

It's been known for awhile the PTool3 software in its current form won't work with a future "GH2", at least not at first, so the road ahead is uncertain but promising.

 

Stay tuned.

 

- Peter

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Damn. Almost talked myself into it as well.

 

I wonder if there is a way to tell if you're getting one that's been on a shelf for a bit, or if it has that firmware version.

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... I wonder if there is a way to tell if you're getting one that's been on a shelf for a bit, or if it has that firmware version.

 

I don't know how accurate the following info is concerning "hackable" GH1 serial numbers, but see:

http://www.dvxuser.c...56&postcount=35

http://wiki.eoshd.co...Hackable_Models

 

 

EDIT: My thread for Panasonic's new DMC-GH2 camera is here:

http://www.cinematography.com/index.php?showtopic=48216

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