GH5 Panasonic GH5 6K Video upscaled to 8K YouTube frame

To be fair the new ARRI Alexa is a 65mm 6k camera but when shooting 16x9 it has a crop that uses 5120x2880 pixels for 5 perf 65mm film. The GH5 can also shoot 6k as 5184x3456 which gives it more than enough pixels to fit within that same definition the Alexa 65 uses. If ARRI can get away with it so can Panasonic. The Alexa 65 can shoot open gate at around 6500 pixels wide or 16x9 for 5120 pixels wide. If you shoot 5184 6k on the GH5 and crop the vertical down to 2880 you essentially have the same 6k 16x9 resolution as the ARRI Alexa 65. Too bad the GH5 can only do 6k at 30p.
 
Thomas Smet said:
To be fair the new ARRI Alexa is a 65mm 6k camera but when shooting 16x9 it has a crop that uses 5120x2880 pixels for 5 perf 65mm film. The GH5 can also shoot 6k as 5184x3456 which gives it more than enough pixels to fit within that same definition the Alexa 65 uses. If ARRI can get away with it so can Panasonic. The Alexa 65 can shoot open gate at around 6500 pixels wide or 16x9 for 5120 pixels wide. If you shoot 5184 6k on the GH5 and crop the vertical down to 2880 you essentially have the same 6k 16x9 resolution as the ARRI Alexa 65. Too bad the GH5 can only do 6k at 30p.
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Also GH5 6k uses low bitrate (128 kb) audio.
 
Vesku said:
Also GH5 6k uses low bitrate (128 kb) audio.
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Yes an issue but a movie that would need 6k shots would also very likely use dual system sound recording with a dedicated person handling the audio. The audio in 6k on the GH5 (which I didn't even know it could do audio) is really just there to help sync to the dual system audio. Not a big deal for those who would actually make good use of 5k, 6k or anamorphic.

The thing that really kills 6k for film making on the GH5 is the lack of 24p. Panasonic can't exactly use the excuse the processor can't handle it either. 24 frames would be less strain on the processor than 30 frames are.
 
Thomas Smet said:
The thing that really kills 6k for film making on the GH5 is the lack of 24p. Panasonic can't exactly use the excuse the processor can't handle it either. 24 frames would be less strain on the processor than 30 frames are.
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I agree, it should be an easy fix in the firmware to allow 24p as well.

It is interesting, rumors have it the GH5 will have an update to do raw at 20fps (to match the Sony A9), couldn't they have squeezed out 4 more frames?

Oh well, we just have to ask the actors to move a bit faster and then slow down the 30p to 24p in post :tongue:
 
Cary Knoop said:
I agree, it should be an easy fix in the firmware to allow 24p as well.

It is interesting, rumors have it the GH5 will have an update to do raw at 20fps (to match the Sony A9), couldn't they have squeezed out 4 more frames?

Oh well, we just have to ask the actors to move a bit faster and then slow down the 30p to 24p in post :tongue:
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I used to shoot music videos that way with a Canon XL1 which only had a fake 30p mode. It was such a pain.
 
But ultimately the question is does it matter?

I made two videos with the GH5, one at 4K and one at 6K, then compared the two frames. To me it seems the 4K has a better dynamic range, has less noise, does better anti-aliasing and has a similar resolution as the 6K and both have some artificial sharpening applied to it in camera.

https://www.dropbox.com/s/56zl3ikji9g7gro/compare 4k-6k.tif?dl=0

The 6K video (upscaled to an 8K YouTube 16:9 frame)

The 4K video
 
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Cary Knoop said:
But ultimately the question is does it matter?

I made two videos with the GH5, one at 4K and one at 6K, then compared the two frames. To me it seems the 4K has a better dynamic range, has less noise, does better anti-aliasing and has a similar resolution as the 6K and both have some artificial sharpening applies to it.

https://www.dropbox.com/s/56zl3ikji9g7gro/compare 4k-6k.tif?dl=0
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I'm not sure it matters much over 4k to be honest. The extra resolution is kind of splitting hairs and due to the processing used in the GH5 which samples 9 surrounding pixels for each pixel when scaling down I think the amount of resolved detail will end up roughly the same give or take a tiny amount. Using the 5k (6k) as a form of over sampling is almost pointless because thats exactly what the GH5 already does when it shoots 4k video. It uses the full sensor as a form of over sampling and it does so at the raw level before compression. Any post down conversion from the 5k video will never be as good as the uncompressed pathway the GH5 itself already does when shooting 4k video.

Unless somebody actually has a extremely specific use case for that resolution of video and will deliver at that resolution I'm not sure it makes much sense to use it. I guess it could be somewhat useful in tracking and stabilizing situations but for normal video production uses it will likely serve little purpose.
 
Thomas Smet said:
I'm not sure it matters much over 4k to be honest. The extra resolution is kind of splitting hairs and due to the processing used in the GH5 which samples 9 surrounding pixels for each pixel when scaling down I think the amount of resolved detail will end up roughly the same give or take a tiny amount. Using the 5k (6k) as a form of over sampling is almost pointless because thats exactly what the GH5 already does when it shoots 4k video. It uses the full sensor as a form of over sampling and it does so at the raw level before compression. Any post down conversion from the 5k video will never be as good as the uncompressed pathway the GH5 itself already does when shooting 4k video.
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Indeed, the test results seems to corroborate what you say.
 
Thomas Smet said:
I'm not sure it matters much over 4k to be honest. The extra resolution is kind of splitting hairs and due to the processing used in the GH5 which samples 9 surrounding pixels for each pixel when scaling down I think the amount of resolved detail will end up roughly the same give or take a tiny amount. Using the 5k (6k) as a form of over sampling is almost pointless because thats exactly what the GH5 already does when it shoots 4k video. It uses the full sensor as a form of over sampling and it does so at the raw level before compression. Any post down conversion from the 5k video will never be as good as the uncompressed pathway the GH5 itself already does when shooting 4k video.
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GH5 6k video uses long GOP 200Mbs HEVC. It is comparable to 400Mbs h.264 ipb or 1000Mbs intra. The video quality of 6k photo is much higher than normal 4k 150Mbs videos. You can try saving a in-camera photo from 4k video and compare it to 6k photo. 6k photo is actually almost better than full resolution JPG because it is 10bit. It also has amost no moire because it is 100% sensor pixels. If you see aliasing it is caused by player/editor down sampling.
 
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Cary Knoop said:
I agree, it should be an easy fix in the firmware to allow 24p as well.

It is interesting, rumors have it the GH5 will have an update to do raw at 20fps (to match the Sony A9), couldn't they have squeezed out 4 more frames?

Oh well, we just have to ask the actors to move a bit faster and then slow down the 30p to 24p in post :tongue:
Click to expand...

I remember reading somewhere that there will be a full sensor 24P (or 3:2) video mode coming with FW update. I am not sure but it would be technically possible.
 
Vesku said:
GH5 6k video uses long GOP 200Mbs HEVC. It is comparable to 400Mbs h.264 ipb or 1000Mbs intra. The video quality of 6k photo is much higher than normal 4k 150Mbs videos. You can try saving a in-camera photo from 4k video and compare it to 6k photo. 6k photo is actually almost better than full resolution JPG because it is 10bit.
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That's the theory.

I would love to have this be true but I ran a test comparing the videos and I cannot corroborate 6K is any better than 4K.

Vesku said:
It also has amost no moire because it is 100% sensor pixels. If you see aliasing it is caused by player/editor down sampling.
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I do not think it is that simple.
 
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"4k/6k photo video" has best video quality and it has one thing better than normal video modes. It shows exposure info during shooting. There is still one drawback in "4k/6k photo video". It has no single focusing AF so the AF is constantly hunting and doing something.

So no exposure info in normal video modes and no AFS in 4k/6k photo. Why remove basic features? Why different user logic in different shooting modes?
 
Is the 4k photo using HEVC ? 4k 60P with HEVC would be better than h.264.
edit:
6K PHOTO: MP4 (H.265/HEVC, Audio format: AAC (2ch))
4K PHOTO: MP4 (H.264/MPEG-4 AVC, Audio format: AAC (2ch))
 
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