Lumix GH4



Av8Chuck

Av8Chuck

Member
kloner said:
doesn't this thing already do something like that to sd? 1080 200mbs?
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Yes it records 1080 @200Mb/s, but your still compressing it at 8bit 4:2:0. The difference in the higher data rate is that its not compressing it using a long GOP, each frame is an individual frame. I believe, but I don't know first hand that the GH4 sensor will output an HDMI 1080 at 10bit 4:2:2, although its only HD it would have more color information.

The real benefit would be if there was a recorder capable of 4K @ 10bit 4:2:2, then you'd have the resolution and the color information.
 



Av8Chuck

Av8Chuck

Member
kloner said:
that's crazy how these all work on any camera....

whats this all mean at this page?

http://www.eoshd.com/content/12140/discovery-4k-8bit-420-panasonic-gh4-converts-1080p-10bit-444

is that a similar way of going about it? what are they saying to do?

yea, the gh4 has that output at the hdmi... i bet once your this route the signal out of hdmi isn't compatible with any current hdmi converters for fpv...
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That's an interesting article but it leaves out the one important step and that's how do you encode from the GH4's 4:2:0 codec to RGB 4:4:4? What software do they use? I'm encoding with MPEG Streamclip to ProRes (HQ) 4:2:2 but I doubt that the result is a true 4:2:2. I would think that the output from the Ninja should work with current HDMI converters.


kloner said:
chuck, isn't the one i linked do it?

http://www.atomos.com/shogun/
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It certainly looks like that should work. That's looks like a cool recorder but I think its off to solve two problems, the HDMI recording and providing a monitor to view the recording in realtime. We don't necessarily need the monitor. I'd imagine that by the time this is available there will be other recorder only versions to choose from.
 


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textilet

Member
Your color issue is likely because the "d" format is to capture maximum dynamic range. Maximum information assuming color grading is to follow. Like the footage from a BMPCC it will appear flat prior to grading. The good news is that the color is there already it just needs to be graded. If you want better color with no grading don't use that profile; it is intended to capture the most information in highlights and shadows. This will come at the expense of "pop" in colors and contrast, these can be restored in post. I would never fly a Shogun (much of its weight is due to high quality monitor). Unless you're grading your footage and finding it too limited, the problem is in (lack of) post, not in the footage
 
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Av8Chuck

Av8Chuck

Member
All the cine curve does is lower the white point then roll off the top of the log curve and raise the black point and linearize the bottom, that's what gives it the flat look then you can balance and add contrast in post. The problem is this is very effective in 10 bit log, like cineon or DPX [kind of what's refereed to today as RAW], but with these codec's your still only working with 8bit linear 4:2:0 footage so even if your using Resolve to correct, the color data just isn't there. That's not to say that you can't make it look good but the difference in profiles is where you start your corrections from.
 

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textilet

Member
I guess my point is if you haven't tried and failed to tailor your product in post, the problem is not the source footage. Camera settings+post can remedy most "flat color" issues even with "only" 4:2:0 8 bit. Most MR video is just landscape essentially and can be captured just fine with those limitations. Higher bit rate and deeper color space help with large color correction, but aren't necessary if you just want the video to" look how it looked" Especially with the resolution at hand with the gh4. If I wanted to improve my source image with gh4 + MR I would look at atomos ninja star at most, weight penalty of flying the shogun isn't worth it because the gh4 makes good images without it. The problem isn't the camera or footage, it's probably lack of processing or wrong camera settings.
 
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kloner

kloner

Aerial DP
we do cinema with epics for work, then i come home and play with gh4 and it just feels flat and lacking. the people we fly epics for have no interest in it.

I played with some of these upscaling softwares. guess i'm getting a better color correction with all the same color corrections.... Ones 5dtorgb, get it at the apple app store and the other oddly enough is the hero software.... the part i don't see is how i go from 4k to 1080 and have no idea if i'm actualy making it to 422.... but it looks better.


 
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soggybottoms

Member
on the first video it seemed to depend on the subject which looked better. the leaflets looked better on gopro to my eye
the second vid the 5d3 wins it with the gopro a close 2nd
my GH4 just arrived so I have all this fun ahead of me :)
 



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textilet

Member
I believe filmconvert, which is similar and I think now has gh4 presets, has a premier version. Filmconvert also has a good demo video
 

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textilet

Member
I would also recommend the eoshd gh4 guide, which has lots of great info on settings and presets so you can choose between modes that look like crap out of the camera but have lots of room to grade, and modes that pop straight from the camera but have less room to push/pull in post. I learned from the BMPCC that sometimes I don't want to have to grade the image much.
 

kloner

kloner

Aerial DP
that's an interesting deal,,, some looks better, others worse,,,, i gotta get a better understanding of what i'm doing obviously....

is adobe speedgrade something like this? I have the cloud complete suite, never looked at it yet.
 

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textilet

Member
I've never worked with Adobe. But I would guess that if you go through that eoshd guide you will find a camera setup that will get you 90% of the way to where you want to be before you even start messing with the footage in post
 

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fpmurphy

Member
Speedgrade is Adobe's color grading software. The newest version of Premiere also includes Lumitri Looks under the effects tab. You can create new looks with Speedgrade and they should be brought into Premiere.
 

kloner

kloner

Aerial DP
I'll have to install that and check it out.... thanks for the info

that film convert is better standalone, makes more since and a lot more control....took a few of the clips used above and graded them, made to 422 pro res and uploaded...


with my fat thumbs tweeking it...
 
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