GH5 vlog noise and 10bit strange behaviour

[Petter Magnusson]

1. VLOG L

I have done some extensive test with GH5 vlog vs Cinelike D and 8bit vs 10 bit. Here are my findings:

vlog is way much more noisy than Cinelike D, I think vlog 3200 iso looks like cinelike D 800 iso when both are graded to look the same. However, vlog seems to be much less sensitive to Noise Reduction in camera than other profiles, I have Cinelike D NR at 0 and that is max for me to look good, while with vlog I can use NR +5 and it still looks sharper! With those settings the noise of vlog looks roughly like the noise level for Cinelike D at the same ISO.

Conclusion for me: Anything above iso 3200 is unusable no matter what. For Cinelike D use NR=0, for vlog use NR+5.

 

 

2. 10bit

On 8bit vs 10 bit I have the strangest thing, if I do a test recording comparing 8 and 10 bit Cinelike D files, the 10 bit file has much more contrast and less dynamic range!

My settings are GH5, FHD, ISO 400, MP4 LPCM, Cinelike D with Sharpen -3, Saturation -2, Firmware 1.1, lum 0-1023/0-255, iDyn off, iRes off, Highlight Shadow Standard

I use Premiere Pro CC (I have no problem playing 10 bit files FHD and 4K however!)

Can anyone reproduce this? Shoudl not 8 and 10 bit have the same dynamic range when ungraded? Sure looks like a bug to me!

 

Using vlog I also get more contrast using 10 bit, but there it will not limit the dynamic range so will only do good (less banding and artifacts when grading). However, the maximum dynamic range of the camera will not fill out the 0-1023 range, only roughly half, so the real bit depth is around 512 levels and not 1024, so 9bits when using vlog. 

Conclusion: Always use 8 bit with Cinelike D and always 10 bit with vlog.

 

[hyalinejim]

15 minutes ago, Petter Magnusson said:

while with vlog I can use NR +5

If you have the time and the inclination you might get better results using Neat Video in post on V-Log material shot at -5 NR. Neat Video gives great results if you shoot a colour chart and build a custom noise profile for each ISO. Often, I use temporal NR only and not spatial as this is enough. It's also good to prep V-Log material if you're going to use strong LUTs, even at ISO 400.

 

17 minutes ago, Petter Magnusson said:

the 10 bit file has much more contrast and less dynamic range!

This is probably how Premiere is interpreting the file - there is info above 100 and below 0 IRE. Use curves to pull it back. At least that's how 10bit CineD behaves for me in After Effects (32 bit colour space).

[Fritz Pierre]

Vlog is notoriously noisy at high ISO...not recommended when you're shooting in low light...as I don't have one yet I can't say, but I imagine in low light Natural or CineD would be better choices at higher ISOs

[Petter Magnusson]

1 hour ago, hyalinejim said:

If you have the time and the inclination you might get better results using Neat Video in post on V-Log material shot at -5 NR. Neat Video gives great results if you shoot a colour chart and build a custom noise profile for each ISO. Often, I use temporal NR only and not spatial as this is enough. It's also good to prep V-Log material if you're going to use strong LUTs, even at ISO 400.

 

This is probably how Premiere is interpreting the file - there is info above 100 and below 0 IRE. Use curves to pull it back. At least that's how 10bit CineD behaves for me in After Effects (32 bit colour space).

Hi, yes denoising in post is better, but takes a lot of time to render for quick jobs....so these are findings for that situation. Do you think vlog is more or less noisy at the same iso with optimal denoising?

 

In 10bit mode the info is really lost for me using Cinelike D. 

9 minutes ago, Fritz Pierre said:

Vlog is notoriously noisy at high ISO...not recommended when you're shooting in low light...as I don't have one yet I can't say, but I imagine in low light Natural or CineD would be better choices at higher ISOs

I am not so sure. It just has less denoising applied I think (on the GH5, onthe Sony a7s II its a different situation, there you need to overexpose 2 steps since the iso is not what you might expect using slog).

[hyalinejim]

12 minutes ago, Petter Magnusson said:

In 10bit mode the info is really lost for me using Cinelike D.

Quote

This is probably how Premiere is interpreting the file - there is info above 100 and below 0 IRE. Use curves to pull it back.

 

[Petter Magnusson]

1 hour ago, hyalinejim said:

 

Nope, its really lost. 

[hyalinejim]

 

Try this with the Luma corrector effect to recover info that's outside of range - raise pedestal and lower gain.

[Petter Magnusson]

3 hours ago, hyalinejim said:

 

Try this with the Luma corrector effect to recover info that's outside of range - raise pedestal and lower gain.

You are right, it works with Luma Corrector, but I cant get the information back using only Lumetri Color. Isnt that strange!? Looks like a bug anyway?

[hyalinejim]

Yes! It's one of the reasons I don't really like Lumetri although I know that many people love it.

[pablogrollan]

10 hours ago, Petter Magnusson said:

You are right, it works with Luma Corrector, but I cant get the information back using only Lumetri Color

Usually you can do it from Lumetri, you just need to check the box "High Dynamic Range", though I haven't tried it with GH5 footage at all.

[Michael Coffee]

Nice thread, very informative! Cheers