GH4 GH4 V-log?

TheDingo said:
Illya, can you post any V-log frames that demo what can be done visually with this new format ?
Click to expand...

I can, but I'm visiting family for the holiday and have no access to the equipment or stuff I've already shot until mid-late next week. I think there's some other stuff that's been shot and out there already.

The only example I can give you is not ideal. You can still see detail in the Dad's trunks. Even 8-bit, compressed for youtube, mac screenshot and then compressed from PNG to jpeg (medium) 148K, and then uploaded here- you still get apparent detail in the shadows which can be lifted in software as simple as a Mac Finder "Preview" which is pretty stunning all things considered. The sun sits right on the edge of clipping (red channel is just over) but still there's chroma detail in the brightest part of the highlight. Generally you'd need to stop down to hold that, and you would lose all detail in the people which should have been pure silhouettes, but with V-Log-L they aren't- you can see some detail in the boy's shirt and the father's trunks. The shape of the sun is a bit distorted because of the Cineovision anamorphic lens flare. There was no fill lighting on the people, no filter on the lens, and no real color correction other than a small adjustment in contrast.

Sunrise.jpg
 
wwjd said:
PLEASE PLEASE PLEASE ask them for aspect markers on LCD: 2.40:1 or 2.39:1, and ALSO to max out the 4k recording pixel count to whatever the processor can handle, like 4.2k or 4.6 whatever
Click to expand...

You can mask 2.40 yourself, and a number of external devices will as well. There's already more resolution then some $80K+ camera systems that claim 4K.

I'm trying to convince them to de-squeeze anamorphic internally/externally for the LCD/EVF. That would be amazing.
 
Last edited:
Bassman2003 said:
Is this a veiled reference to Magic Lantern? ML seems to be quite Canon specific. No doubt that a RAW GH4 4k image would be quite a nice image to work with. No idea how to get that train started though...
Click to expand...

Nope. Knowing a bit about ML and what they are doing (or not doing as the case may be) I would not put a bet down on them for any non-Canon camera.
 
Illya Friedman said:
In the version I have currently, if your histogram is climbing the far right side then you are starting to clip. I would need to put it on a 7Q+ or other waveform to tell you the specific IRE. I can do this next week when I am back from vacation if you would like?
Click to expand...

Thanks Illya, that's good to know about the histogram, the IRE will be apparent soon enough when V log lands so no worries there. Thank you.
 
Illya Friedman said:
Nope. Knowing a bit about ML and what they are doing (or not doing as the case may be) I would not put a bet down on them for any non-Canon camera.
Click to expand...

Thanks for you reply. I have to ask then, what RAW video hack reference are you pointing to?

BTW, I do not understand the resistance you are getting about the images. The tonal representation is pretty impressive for a $1,300 camera!
 
Illya Friedman said:
In the version I have currently, if your histogram is climbing the far right side then you are starting to clip.
Click to expand...

a simple but very realistic looking kind of answer! -- thanks :)

but another question:
would it be possible for you to upload a few very shot snippets of internally recorded V-Log-L footage showing IT8 charts or something simiar -- any kind of cholor-/greyscale chart with a lot of patches and publicly available reference data -- using exposure on the point and +/- a few LV?

it it's fine for me to debate the subjective perception of color rendering and dynamic range, but i still prefer to proof and compare it by objective measurements of color managment tools.
 
Illya Friedman said:
You can mask 2.40 yourself, and a number of external devices will as well. There's already more resolution then some $80K+ camera systems that claim 4K.

I'm trying to convince them to de-squeeze anamorphic internally/externally for the LCD/EVF. That would be amazing.
Click to expand...
Illya

when most of us ask for a 2.4 aspect ratio, we are asking for 4608x1920, not 4096x1706. We want to use the full width of the m43 sensor. As it happens 4608x1706 has exactly tha same pixel count 4096x2160. Aside from the modification of the menus, which is nothing, I suspect only the parameters for where to start getting data from the sensor and the end point for where to stop. All of this amounts to little more than additions to the fimwares data array.

Hey maybe we should start a crowd funding to pay Vitaly to hack the gh4 and set up a ML type of group.
 
walkaboutcamera said:
Hey maybe we should start a crowd funding to pay Vitaly to hack the gh4 and set up a ML type of group.
Click to expand...

People donated money to Vitaly to hack the GH3, and to date he has not succeeded. It is even less likely he can hack the GH4.

Users would be better off making the most of the gear and software available to them, than this pipe dream of Vitaly turning the GH4 into a new camera.
 
thorn said:
People donated money to Vitaly to hack the GH3, and to date he has not succeeded. It is even less likely he can hack the GH4.

Users would be better off making the most of the gear and software available to them, than this pipe dream of Vitaly turning the GH4 into a new camera.
Click to expand...

Sad but true, just venting my frustration with manufactures not fully utilizing the hardware. I for one am in favour of tiered levels of firmware based on what the customer is willing to pay for.
 
thorn said:
People donated money to Vitaly to hack the GH3, and to date he has not succeeded. It is even less likely he can hack the GH4.

Users would be better off making the most of the gear and software available to them, than this pipe dream of Vitaly turning the GH4 into a new camera.
Click to expand...

I agree. The GH2 hack always made me nervous because, while we could get better encoding, we were in fact going beyond what manufacturers had calibrated the machine for - and there was some instability as a result.
 
It's cool to play around with hacks, if that's your thing. I found Sanity 5.1 to be pretty stable on my GH2. Didn't blow my mind, but it was an improvement.

But it's kind of funny when people (I'm not talking about walkaboutcamera)somehow think that Vitaly has some sort of divine insight to firmware code & algolrythms, that the entire Panasonic (or Samsung, or Sony) engineering team has never even possibly considered.
 
Illya Friedman said:
You can mask 2.40 yourself, and a number of external devices will as well. There's already more resolution then some $80K+ camera systems that claim 4K.

I'm trying to convince them to de-squeeze anamorphic internally/externally for the LCD/EVF. That would be amazing.
Click to expand...

Yes... I can.... but tired of sticking gaffers tape on to do it. :( I mean show that ratio ON the built in monitor. But yes, would love 4.6K as well...
 
mash_gh4 said:
a simple but very realistic looking kind of answer! -- thanks :)

but another question:
would it be possible for you to upload a few very shot snippets of internally recorded V-Log-L footage showing IT8 charts or something simiar -- any kind of cholor-/greyscale chart with a lot of patches and publicly available reference data -- using exposure on the point and +/- a few LV?

it it's fine for me to debate the subjective perception of color rendering and dynamic range, but i still prefer to proof and compare it by objective measurements of color managment tools.
Click to expand...

Entirely possible. But I'm on vacation this week, and then out of the country at IBC. I don't return until after V-Log-L is shipping so I suspect someone will beat me to it. If they don't, when I get back I'll see about shooting a test with a Xyla 21.
 
Bassman2003 said:
Thanks for you reply. I have to ask then, what RAW video hack reference are you pointing to?
Click to expand...

Someone else mentioned RAW, I never said anything about RAW. All I said was I was surprised that no one has really gone after hacking the camera. The camera is incredible and there is precedence from previous GH camera models.

On the legitimate improvement front, all I can say is that there is internal and external (to Panasonic) effort to constantly make the GH4 even better. If a collective of respected voices are successful, I expect we'll see further updates that would make "cinema" style users very happy, and ultimately win additional customers for Panasonic.
 
walkaboutcamera said:
As it happens 4608x1706 has exactly tha same pixel count 4096x2160.
Click to expand...

4096x2160 = 8.8MP (1.89:1)

4608x1706 = 7.8MP (2.7:1)

I think you meant to type 4608x1920.

I don't know how it works with the GH4, but I do know on certain types of sensors there can be problems with going full width on a sensor, especially if the edge photosites are used for another purpose and not actually sensitive to light. I don't know if this is the case with the GH4, but some manufactures have claimed a total resolution based on photosite that do not actually result in a full pixels worth of information. There is one famous example of this, from a camera "manufacturer" that claimed to be using a "5.7K" sensor back in 2006, this of course was a lie.

There are a number of sensor which move data/electrons through specific columns/or rows around the edge that are not used for another purpose. Other sensors set aside some photosites for black reference, and then can avoid the black balance/black shading procedures that some other cameras need in order to function.

Regardless of an 8.8MP count being the same, my guess is that the arrangement of those pixels into something other than currently exists is likely a non-trivial matter. I would also suspect that as 4608x1920 is not a SMPTE or DCI standard, it's unlikely that Panasonic would add it without a lot of requests. I think it's more likely you would see 4096x1714, but (if you get framelines) you can add the crop in post easily and have room to reframe.

I will suggest this to Panasonic, as I believe the supersampling of a 2.39 capture with 4608 width (or some fraction higher than 4096) may have value if they can work the math so there are no scaling artifacts. I'm pretty certain they would still want to send it to the card with a mild scale to 4096x1714 to maintain DCI and not give an NLE (or other commodity software) a fit from a non-standard raster/file resolution. It would lessen the "crop factor" and probably result in an image with more resolution. A good suggestion if it's technologically possible.

There's a lot of players that have to be involved when you deviate to far from "the norm." If you are a manufacturer and you want your image file to enjoy wide cross-tool/platform support, then following standards make life easier.
 
Illya Friedman said:
On the legitimate improvement front, all I can say is that there is internal and external (to Panasonic) effort to constantly make the GH4 even better. If a collective of respected voices are successful, I expect we'll see further updates that would make "cinema" style users very happy, and ultimately win additional customers for Panasonic.
Click to expand...

Sounds great...after all the Gh2 had a long life (still going strong too) based on a hack and patches, so its got to be good for Panansonic to do this, the more they do it, the more sustained interest in the Gh4.

One thing I think tho...if LPowell is correct about the possibility that the VLOG-L is not using the 8 bit codec to its best advantage, it may be an idea to make a GH4 specific LOG that uses the full range and spreads into the 8 bit codec better,
not everyone wants to intercut with the Varicam and I am sure plenty of people will be rushing to make LUTS for any GH4 specific Log.

Some type of advanced noise reduction (even after shooting...like the Time Lapse Video creation) would be nice, a noise reduction that specifically cleans up to the dancing noise above 1600 ISO that lurks in the shadows, I know Neat Video can deal to this, but theres something about doing it in the camera thats totally convenient, and I am sure the CPU has the power to do it...post shooting.
This would be huge!! I would pay gladly for that feature alone!
Thanks
 
Removing that noise will make the compression more efficient, it won't be spending bit rate to encode the noise.

As far as hacking this camera, pretty sure that if it was possible, it would have been done by now. I'm guessing that Panasonic encrypted the firmware in the gh3 and gh4 to combat the hacking in the gh1 and gh2. It apparently worked because no one has managed to hack them (that we know of). Vitaliy was working on gh3 hack, but it never came to be which suggests it isn't going to happen. I'm sure they improved the gh4 protection with the faster processors. This does bring up the question of why Panasonic cares if we hack it??? The hack certainly helps sell more cameras, but I guess it could prevent some people from upgrading to the next camera.
 
Illya Friedman said:
Someone else mentioned RAW, I never said anything about RAW. All I said was I was surprised that no one has really gone after hacking the camera. The camera is incredible and there is precedence from previous GH camera models.

On the legitimate improvement front, all I can say is that there is internal and external (to Panasonic) effort to constantly make the GH4 even better. If a collective of respected voices are successful, I expect we'll see further updates that would make "cinema" style users very happy, and ultimately win additional customers for Panasonic.
Click to expand...

Thanks for your reply. I get a sense that Panasonic is catching on with what the video crowd wants out of these cameras. A while back Barry Green posted a company induced question as to what people want to see in the future out of the GH line. I think one can summarize the community's desires in one thought - take away all of the compromises (many on purpose) with these cameras. As an outsider to their production challenges and costs, I can only guess what is feasible but I think they would benefit from releasing a GH5V as a video centric variant. Then this more expensive model could have fewer limitations and more meat. That is what folks want. Creating a great video tool but keeping it hobbled because it is a "still" camera is just tired and old.
 
You must log in or register to reply here.
Back
Top