1080p 60fps on GH2 with hack?

Z

Zoeff

New member
Hello everybody, first post here! :)

I've been looking for a camera with a DSLR sized sensor (including DSLRs) and ended up homing in on the GH1 and GH2. To my surprise I found this forum talking about custom firmware only to be disappointed to learn that panasonic tightened security on later shipments of GH1's making it much more difficult to hack. Is it even possible to find one in a shop with the required firmware version nowadays? I'm guessing they're all sold already.. :(

According to dpreview, the sensor in the GH2 is actually capable of 1080p at 60fps but there are "no common ways to distribute 60p or 50p footage" and instead you end up with 60i. Personally, I loath 24p and interlaced even more, so this is quite disappointing for me. Assuming that panasonic is actively trying to prevent the firmware being hacked, what are the chances that the GH2 will be hackable? I'd quite like to see 1080p60 along with a high bit rate available for the GH2.

Thank you,
Zoeff
 
there are endless threads on this, do a search on those terms, and then lock yourself in your house for 4 days reading....
 
Why do you hate 24p so much? It offers the highest bit rate per frame of all of the standard frame rates. It is also the standard for all major movies and most TV shows that are/were shot with film.

24p definitely is not the best for sports. However, it is the best choice for low light movies and any movies that don’t have a lot of fast movement.

There are ways to do high speed motion with 24 FPS though. Next time you watch an action movie look at what they do with the high speed scenes. They almost always show them in slow motion. With the GH1/GH2/GH13 you can always shoot in 720p @ 60 FPS and do slow motion at 24 FPS and it will look great.

My personal view on the hack is, “Ask yourself why you think you need the hack. Is it just because you want to have the camera with the highest bit rate or is it because you have a legitimate need for an enhancement”.

There are major drawbacks to 1080p @ 60 FPS movies(Bit rate, it isn’t possible to share it currently, shutter speed issues…etc). Try out the 1080p @ 24 FPS and the 720p @ 60 FPS before you start asking for something you might not be able to use anyway.
 
To me, 24p jitters even when done by the professionals. I hate it with a passion, any sort of panning unless it's seriously slow will confuse my eyes. I'm probably a lot younger than most of you, so I don't share this natural affinity with a 100 year old standard.
 
If you pan with a subject usually you're ok. 24p is not the standard because it's old, 24p is the standard because it gets closest to what the human eye sees. Wave your hand in front of your face, move your head around at a high speed: stroby motion, with motion blur. That's what our eyes see. 60p, etc, seem too unnatural to me, because they're smoother than what your eye would see if that situation were real, rather than being played out on a screen.
 
Actually the eye doesn't see the world with stroby motion. If you sit on a turnable chair and rotate it then your eyes always focuses on a new object, that's why it seems stroby to you. When you hold you finger in front of your face and concentrate on this finger while rotating the chair, the out of focus background will move past your finger without any strobing.
 
Ben_B said:
If you pan with a subject usually you're ok. 24p is not the standard because it's old, 24p is the standard because it gets closest to what the human eye sees. Wave your hand in front of your face, move your head around at a high speed: stroby motion, with motion blur. That's what our eyes see. 60p, etc, seem too unnatural to me, because they're smoother than what your eye would see if that situation were real, rather than being played out on a screen.
Click to expand...

I either snap the field of view of my eye from one place to another or am locked on a moving subject during which the background is blurry and not intrusive. I don't know about you but I can't pan with my eyes at all, and I don't see any sort of strobing. What I want my camera to do is simulate the real world after which the eye can be moving around in that. Personally I'd prefer 120fps but obviously that's not very practical and the improvement over 60fps isn't that great anyway.
 
Ben_B said:
If you pan with a subject usually you're ok. 24p is not the standard because it's old, 24p is the standard because it gets closest to what the human eye sees. Wave your hand in front of your face, move your head around at a high speed: stroby motion, with motion blur. That's what our eyes see. 60p, etc, seem too unnatural to me, because they're smoother than what your eye would see if that situation were real, rather than being played out on a screen.
Click to expand...

Ben youre wrong. Its not close tohuman eyes
 
mpgxsvcd said:
There are major drawbacks to 1080p @ 60 FPS movies(Bit rate, it isn’t possible to share it currently, shutter speed issues…etc). Try out the 1080p @ 24 FPS and the 720p @ 60 FPS before you start asking for something you might not be able to use anyway.
Click to expand...
I don't find these "drawbacks" major at all:
1) Bitrate should be adjustable.
2) [Network] distribution method is a secondary consideration, when one can capture the maximum amount of temporal and spatial resolution (if that's what is important) and downscale (spatially or temporally) from the master. Already today Viimeo allows an action flick shot at 1080/60p to be distributed via the download option. When tomorrow they enable their player to stream at 1080/60p your 1080/30p or 1080/60i or 720/60p material will have to get reshot to take advantage of the new capability. If maximum allowable resolution is within hardware/software/budgetary limits why settle for less; much less advocate it?
3) What shutter speed issues?
 
It would be nice if we can use multi fps modes in a same footage. 24pN for some scene and 30p or 60p for fast action.

If it is truly digital, why can't it deploy multi modes? Possibly header meta info could tell about different sections in a footage.
 
svecher said:
I don't find these "drawbacks" major at all:
1) Bitrate should be adjustable.
2) [Network] distribution method is a secondary consideration, when one can capture the maximum amount of temporal and spatial resolution (if that's what is important) and downscale (spatially or temporally) from the master. Already today Viimeo allows an action flick shot at 1080/60p to be distributed via the download option. When tomorrow they enable their player to stream at 1080/60p your 1080/30p or 1080/60i or 720/60p material will have to get reshot to take advantage of the new capability. If maximum allowable resolution is within hardware/software/budgetary limits why settle for less; much less advocate it?
3) What shutter speed issues?
Click to expand...

Everything is bit rate dependent because the AVC-HD standard puts a maximum cap on bit rate. For example I could record at 28 mb/sec 1080p @ 60 FPS or 28 mb/sec 720p @ 60 FPS or even 28 mb/sec 1080p @ 24 FPS. The 720p and 24 FPS shots will get more bits per pixel than the 1080p @ 60 FPS shots.

It doesn’t make sense to shoot in 1080p @ 60 FPS since you can’t actually share that format right now. You might as well shoot in 720p @ 60 FPS or 1080p at 24/30 FPS to get a higher bit rate per frame/pixel. It will be a long time before 1080p @ 60 FPS is shareable at a reasonable bit rate. It just isn’t useful for native shooting right now. It would be great for slow motion but 720p @ 60 FPS works almost as well.
 
Ben_B said:
If you pan with a subject usually you're ok. 24p is not the standard because it's old, 24p is the standard because it gets closest to what the human eye sees. Wave your hand in front of your face, move your head around at a high speed: stroby motion, with motion blur. That's what our eyes see. 60p, etc, seem too unnatural to me, because they're smoother than what your eye would see if that situation were real, rather than being played out on a screen.
Click to expand...


Haha, I think your eyes are dodgy man, if they only see at 24fps. IF eyes did work in FPS at all, and if it were as low as 24fps, then how can you see that 60fps looks different than 24fps? Shoot a 60fps TV on a 24fps camera, and you won't be able to see that the TV was at a higher framerate.

I'm glad we humans don't have to pan slowly following a subject... that would suck.
 
Zoeff said:
I either snap the field of view of my eye from one place to another or am locked on a moving subject during which the background is blurry and not intrusive. I don't know about you but I can't pan with my eyes at all, and I don't see any sort of strobing. What I want my camera to do is simulate the real world after which the eye can be moving around in that. Personally I'd prefer 120fps but obviously that's not very practical and the improvement over 60fps isn't that great anyway.
Click to expand...


Actually, the human eye can't detect much (if any) difference between 50fps, and 1000fps, as it sort of tapers off (one could say that the eye 'sees' at about 50-60fps, depending on the light).
 
mpgxsvcd said:
It will be a long time before 1080p @ 60 FPS is shareable at a reasonable bit rate.
Click to expand...

We are talking 1080P60 for acquisition, not distribution. It's easy enough to covert it to any distributable present-day format (BluRay, DVD, Iphone, whatever), while retaining a somewhat future-proof master.
 
mpgxsvcd said:
Everything is bit rate dependent because the AVC-HD standard puts a maximum cap on bit rate. For example I could record at 28 mb/sec 1080p @ 60 FPS or 28 mb/sec 720p @ 60 FPS or even 28 mb/sec 1080p @ 24 FPS. The 720p and 24 FPS shots will get more bits per pixel than the 1080p @ 60 FPS shots.
Click to expand...
Like a said, bitrate should be adjustable. The time is nigh for the next revision of AVCHD standard. It doesn't even fully support the equipment of both sponsors any more -- Panasonic and Sony have the second generation of TVs now that support 1080/60p AKA FullHD.

It doesn’t make sense to shoot in 1080p @ 60 FPS since you can’t actually share that format right now. You might as well shoot in 720p @ 60 FPS or 1080p at 24/30 FPS to get a higher bit rate per frame/pixel. It will be a long time before 1080p @ 60 FPS is shareable at a reasonable bit rate. It just isn’t useful for native shooting right now. It would be great for slow motion but 720p @ 60 FPS works almost as well.
Click to expand...
Your conclusion is based on three premises that footage must be shared, straight from the camera (minimal PP) and now. Not everyone has those same needs. Some people just want to take "home videos" that can be shown in their full glory on their FullHD TV. Some people on this board talked about traveling to far off places, like that anthropologist going to Africa to document local dances, who will probably still show footage to his students 5 years from now, when 1080/60p (which is an HDTV distribution standard in the US today by the way) will be the norm. And then there are some people, like Blackout, who take no prisoners when it comes to IQ and will not accept the upresed 720p footage as fodder for slow-motion sequences. Me? I would love to go back to Maui to shoot this kind of stuff in 1080/60p with my GV2.
 
The same arguments was used with the JVC HD1 and then again with the Sony HC1. I bought the HC1 in the summer of 2005 and I'm very glad that I have HD footage that's over 5 years and people could have had HD footage back in 2003 with the HD1. This is a big deal. It's best to have footage that will fare very well years from now. I was choosing between the Panasonic GS400 and the Sony HC1 and thinking about the future is what finally made me decided to spend the extra money and get the HC1 and looking back, I know I made the right decision. This is why I feel that I should also purchase the SDT750/TM700 although most-likely the TM700 since it's only $750. For me to have both a Panasonic 1080 60p camcorder and the GH2, it'll complement each other. I still need to think about this.
 
mpgxsvcd said:
It doesn’t make sense to shoot in 1080p @ 60 FPS since you can’t actually share that format right now. You might as well shoot in 720p @ 60 FPS or 1080p at 24/30 FPS to get a higher bit rate per frame/pixel. It will be a long time before 1080p @ 60 FPS is shareable at a reasonable bit rate. It just isn’t useful for native shooting right now.
Click to expand...
As svecher pointed out, shooting in your target distribution format is only an advantage when you intend to limit post-processing to simple edits and transitions. If you have any need to do color grading, resampling, or effects processing, you really need to start with source material captured with higher bitrate and broader latitude than what you plan to deliver. Every time you render or transcode the original source video, it suffers an irreversible loss in resolution. While it can be artificially sharpened up in the final render, it's far better to start with material that can withstand some degradation and remain intact.

For the purposes of interim file distribution during post, 24Mbps is hardly a fixed cap on AVCHD format. Blu-ray discs and players support video bitrates up 40Mbps and as we've discovered, Class 6 SD cards are reliable at 50Mbps. Adobe CS5, Final Cut, and Sony Vegas routinely handle such bitrates on modern workstations as well.

In my experience, the long-GOP, half-second intervals between key frames is the main stumbling block that makes consumer AVCHD distribution formats unsuitable for post-processing. That's why I was motivated to develop my GH13 Fast Action 3-Frame GOP Patch, which produces 50Mbps 720p30 files that are directly suitable for editing in post, without need for transcoding. With stock GH1 footage, I prefer to transcode it to 40Mbps H.264 High Profile format with a key frame every 1/5th to 1/4th of a second. Ideally, I would like to use H.264 High 4:2:2 Profile, not to "improve" on the original, but merely to minimize degradation of its captured 8-bit 4:2:0 quality. This however requires the Main Concept Broadcast codec plug-in for Adobe CS5, with a licensing cost I haven't yet been able to justify.
 
You must log in or register to reply here.
Back
Top