GH4 C4K vs 4K - 24.00 vs 23.976
- Thread starter aonavy
- Start date
I asked the same question on PV so will paste a response here:
"If you're using Adobe Premiere you can bring the GH4 24P footage into your project and then use the "interpret footage" feature to conform cinema 24.000 Film over to 23.976 NTSC. This should eliminate the chance for odd looking drop frames when you render it out to 23.976. Here is the link: http://helpx.adobe.com/premiere-pro/using/organizing-assets-project-panel.html#change_the_frame_rate_of_a_clip"
"If you're using Adobe Premiere you can bring the GH4 24P footage into your project and then use the "interpret footage" feature to conform cinema 24.000 Film over to 23.976 NTSC. This should eliminate the chance for odd looking drop frames when you render it out to 23.976. Here is the link: http://helpx.adobe.com/premiere-pro/using/organizing-assets-project-panel.html#change_the_frame_rate_of_a_clip"
David W. Jones
Veteran
Aspect ratio is also different.
Thomas Smet
Veteran
Of course it is. You can do just about anything you want with 4k footage in Premiere. Change the framerate, down scale, pan&scan, grab stills or anything else you want to do.
You also have to be careful interpolating 24p footage to 23.976 in Premiere. Doing so could cause your audio to change. You have to make sure your audio also changes by the same amount or else the sync could drift. If you do not need the audio then no big deal.
Honestly the main reason to shoot the full 4k mode isn't as much for broadcast as it for cinema distribution. If you plan on only ever broadcasting then there is very little reason to shooting the slightly wider than 16x9 format. Just shoot the UHD form of 4K and you have nothing to worry about. Save yourself the hassle of cropping and framerate conversion and just shoot UHD at 23.976.
You also have to be careful interpolating 24p footage to 23.976 in Premiere. Doing so could cause your audio to change. You have to make sure your audio also changes by the same amount or else the sync could drift. If you do not need the audio then no big deal.
Honestly the main reason to shoot the full 4k mode isn't as much for broadcast as it for cinema distribution. If you plan on only ever broadcasting then there is very little reason to shooting the slightly wider than 16x9 format. Just shoot the UHD form of 4K and you have nothing to worry about. Save yourself the hassle of cropping and framerate conversion and just shoot UHD at 23.976.
Ryan Lightbourn
Well-known member
About half a million more pixels.
So, doesn't choosing the 'Interpret Footage' option under Modify handle both video and audio?
Cosimo Bullo
Veteran
With our RED the quad HD mode always looked a bit sharper at 1080 than the full sensor readout, I'd guess because the math lines up so nicely.
Yes but do we know if theres any quality difference in how the gh4 is internally interpreting each flavor of 4K to get the different ratios. One might be encoded better than the other. Its binning or skipping in 1080p giving more moire.
Ryan Lightbourn
Well-known member
I can test this out when mine arrives on Fri. if someone can't do it before then.
I always preferred the look of 4.5K WS vs 4K & UHD with my Red One / Scarlet, but this probably has to do with the smaller crop factor (I never did sharpness tests, but for 1080p delivery I could always get more than enough sharpness with no moire/aliasing at all resolutions).
My guess is that 4K & UHD on the GH4 should produce a similar or identical amount of moire at their native resolutions.
Does anyone know how the OLPF compares to Red? My guess is that the GH4 is sharper than MX.
Thomas Smet
Veteran
No.
It all kind of depends on what aspect ratio you want. If you want to continue to have 16x9 then you will end up cropping off those extra pixels anyway. You will still only be down converting a 3840x2160 portion of the video. If you do not crop and want to try and fit the entire video you will end up with a tiny sliver of letter boxing in the 16x9 frame or a slightly stretched out video.
So if you plan on delivering 1920x1080 as a broadcast, Blu-ray, DVD or even web distribution there is no useful reason at all to shoot the 4096 wider mode.
Thomas Smet
Veteran
Cannot recall if it does or doesn't. If it does that means your audio is getting a slight pitch change. Yes it is super tiny but the audio is still getting changed.
Another thing to think about is a multi-camera setup. If you shoot camera A as 23.976 and camera B as 24 and interpolate that 24p to 23.976 then the timing will no longer match up between the two videos. Again it will be very tiny and take a long time to drift but it will. It really is best to just shoot 3840x2160 and not deal with any of the hassle. There is little to no reason to shoot 4096 wide if you don't really need video that wide. Very few would ever think of shooting 4096 as anything but real 24p which is why that is the only option. It is meant strictly for cinema distribution which uses real solid frames instead of the byproduct of NTSC TV which has forced 24p to be 23.976.
Very helpful. Thanks.