What the heck does the hack do to a GH2?

[Lee Ying]

Its not a word play, but my frustration over lack of info on what the hack really adds to GH2 in terms of features and IQ.
Simple google search shows that GH2's most related entry is its "hack". I know people rave about the hack, but with my eyes I cannot tell the difference between the two clips with and without the hack on sites like youtube. I understand the bit rate is increased by 10 fold, but how come I don't see a dramatic improvement in IQ.
Coming from Canon DSLR, I thought the hack would bring tons of additional pro features like focus peaking, zebra and etc., such as in Canon. So, are there any additional features from GH2 hack? where exactly is the noticeable improvement in photo or video to an average person's eye in the hacked GH2?
Thanks much for sharing your thoughts.

[Don Litten]

Hacking your GH2 may not be for you Lee. It's not for everyone and the GH2 does have excellent video right out of the box.

It doesn't add features like focus peeking and zebras. from what I understand the hardware has to be there to improve on those things.

Just increasing the bitrate doesn't mean much. There is a tremendous amount of tweaking that goes on inside each setting.

Recently I've been testing the 444 matrix settings and especially in low light and extremely complicated light, they are amazing.

These frame grabs are high ISO shots from Wednesday straight out of the camera (no post) and all those lights were flashing and strobing.

[Phil Seastrand]

If your not pushing the non-hacked GH2, then you won't see much difference. However, if you shoot a scene where the non-hacked GH2 breaks down, then the hacked version should be significantly better. Try fast motion and/or lots of details with moderate motion. I think you'll find a difference then.

[Ben Giles]

My 2p worth:

I've done some reasonably involved tests with a variety of material and several of the recommended hacks at various bitrates up to 100 Mbps.

I took them into a Pogle/Davinci HD colouring suite and we pushed the grade on all of the files - obviously using the best grade monitors out there and other eyes that I trust - colleagues that regularly work on high end BBC factual and drama.

Nope, we couldn't see any difference. I guess the Emperor wasn't wearing his new threads that day.

I still use the GH2 occasionally and it's always running at native 24 Mbps AVCHD - great little camera.

Ben.

[Thomas Smet]

It really does depend on the type of footage shot. Simple scenes like a talking head interview may not see much of an advantage at all. Other scene like a rapidly running stream of water or a dense tree with blowing leaves will hold up better with one of the hacks.

The way interframe compression works the higher the bitrate the better the encoder will hold up under stress. AVCHD is already optimized for most environments over other formats such as HDV but it still isn't perfect. By raising the bitrate you give the encoder a little extra to work with when the scene gets difficult. The other thing to consider is that many of the hacks use a varable bitate. So even if you have a 100mbit hack a simple scene many still only use 30mbits. It is when the scenes get more complex that the hacks allow the encoder to go above the 24 mbit limit in the native camera.

So the hacks don't maically make the camera look different but they take what it can already do and help it not fall apart under extreme situations. Some hacks do try to enhance detail and color but it is very subtle.

Grading can be greatly improved depending on how high you go and how complex the scene is. Especially if you have to work in dark situations and have to use a higher ISO. Noise and detail in the color channels can be greatly enhanced with the ultra high hacks. To really test grading you have to use complex scenes and use a high enough hack. I use Flowmotion v2 right now and it holds up in even the most complex of scenes. Thinking about moving to new 444 hacks for a visual effects project I have coming up. It isn't true 4:4:4 but from what I have seen it balances the detail between the luma and chroma channels that makes even 4:2:0 work better for keying and grading.

If you use an I frame only hack motion can be enhanced since there is no predicitive frame. Very fast motion will not block up as much. These hacks are however very large and you need very fast cards and the files take up a lot of space. Honestly if you can't see the difference then you probably don't need to use them. Some of us however do see the difference and the higher end hacks have really helped the GH2 shake up the industry.

[Kevin McRoberts]

I've experienced far, far reduced macroblocking in situations like rippling water with wind-blown bird feathers and so forth. For simpler fare, no easily detectable difference.

[Don Litten]

None of us have mentioned is that in some settings, noise is reduced to such a fine degree that it easily passes for grain.

[Thomas Smet]

Other added features may include:

1. Removing the ISO limit when shooting video. Not that I suggest doing so but you can raise the ISO much higher with the hacks allowing one to shoot video in much darker situations then without the hack.
2. If you like to use the mjpeg video mode you can shoot in 1080p instead of the normal 720p.
3. I believe some of the hacks raise the audio bitrate which may help the dolby audio quality.
4. You can switch any model between NTSC and PAL with the hacks. Pretty huge feature if you need it.
5. PAL users can remove the 30 minute recording limit with the hack. This is assuming you have a hack that spans correctly for that long.
6. Record in an I frame only mode which is a new feature coming in the GH3. You can hack the GH2 now to record with only I frames which is insane. I believe some of the hacks go up to 144 mbits. Not very stable however and work best with short shots like shooting a scripted movie. Will never work for live productions. You need a super fast SD card and will fit a fraction of the video on the card compared to unhacked.

[Lee Ying]

Thanks a lot guys for sharing your experience and insight. Its just that from the A-B comparisons I have seen on sites like youtube (which doesn't do justice to fine details) I cannot tell the difference.
I know some of hacked footages look awesome, but I wonder if unhacked GH2 can achieve that anyway or at least pretty close after post editing.
BTW, with more than 100mbps, what SD cards can consistent handle that? If they create unstable recording process, is marginal gain in IQ still worth the cost of occasionally losing footage? I understand the possible benefit of the hack; its dramatic gain many claim in video quality that really puzzles me.

[Don Litten]

Lee, for the higher bitrate settings I use a 95mb card.
BTW, I shot a woman's bodybuilding contest Saturday using the same Valkyrie setting You be the Judge (no post yet).

[Thomas Smet]

Originally Posted by Lee Ying

Thanks a lot guys for sharing your experience and insight. Its just that from the A-B comparisons I have seen on sites like youtube (which doesn't do justice to fine details) I cannot tell the difference.
I know some of hacked footages look awesome, but I wonder if unhacked GH2 can achieve that anyway or at least pretty close after post editing.
BTW, with more than 100mbps, what SD cards can consistent handle that? If they create unstable recording process, is marginal gain in IQ still worth the cost of occasionally losing footage? I understand the possible benefit of the hack; its dramatic gain many claim in video quality that really puzzles me.

Once the video gets on Youtube you eliminate any advantage the hacks gave you which is all about higher bitrates so the quality holds up better. Yes the GH2 without any hacking looks great. The overall detail and look to the image is always there with the camera. The hacks typically just raise the bitrate so that look doesn't fall apart under difficult situations. Some hacks will slightly alter the look but it is very subtle and I doubt you can reLly see it on YouTube which has about the worse video quality you could ever imagine. Try checking out some stuff on Vimeo. Some of the hacks hold up better on there although the quality still gets reduced to levles even below the stock GH2.

The hacks have always been about having the highest quality for editing and grading so the footage holds up better. For keying I find the hacks better because I don't get any macro blocking on the edges which you sometimes can only see when you pull. A key. Especially if you have fast sudden motion such as a hand rapidly moving. On its own it may be impossible to see the difference with the eye but as soon as you key the footage you will start to see it.

I should point out that I don't always use the hacks. I remove the 100mbit hack when I am just shooting personal stuff like vacations. The stock GH2 is great for everyday stuff.

[Bruce Phung]

Originally Posted by Don Litten

Lee, for the higher bitrate settings I use a 95mb card.
BTW, I shot a woman's bodybuilding contest Saturday using the same Valkyrie setting You be the Judge (no post yet).

Don. I have alway enjoyed viewing your image grabs on the forum. They are freaking outstanding images. My question is what type lens are you using? care to share? Thank you.

[Don Litten]

Bruce, I had planned on using my Samyang 85mm 1.7 but at the last minute (I hate to admit this) realized I hadn't put a card in. I grabbed my spare camera with the 14-140 lens which wasn't idea,l but I was able to move around enough to get the light just right and shoot the video.

[Darrell Varga]

Does the hack make a difference if recording the clean HDMI output to an external device? Or does it only matter further down the line related to compression? I am thinking about a GH2/Ninjos combination.