Comments on: Shooting 4K Video for 2K Delivery: the Bit Depth Advantage

By: cpc

cpc — Fri, 12 Sep 2014 13:34:00 +0000

I believe FCPX uses floating point internally, no? It should be 32-bit then. I’ve never used FCPX, so you might need to check this, it is possible that there is some option for project color space bitdepth that needs to be turned on or sth.

Note that in order to see an improvement you either need to be doing some image processing which would stress the lower bitdepth image OR you need to deliver in the higher bitdepth (after downsampling) for viewing on a high bitdepth display (12-bit digital cinema, for exapmle).

Two more things:
1) You get most precision benefits from 4k-to-2K when there is sample variation in nearby pixels in the 4K image. That is, either detail or noise. Soft and clean images will have minimal gains from downscale.

2) Monitoring also comes into play. Small improvements will be noticeable on a quality display but not on lower end displays. Some (most) 8-bit displays are actually 6-bit internally and they may already show banding even if the image is actually perfect in gradation. And for 10-bit gradation diffrences to be visible you’d need a 10-bit display. This only applies for delivarables with minimal processing though. Heavy processing should manifest improvements even on an 8-bit display.

By: Gary Yost

Gary Yost — Fri, 05 Sep 2014 03:01:38 +0000

I’m trying to figure out the best workflow for this. Is this only doable by ingesting all the 4K clips (from my GH4, in this case) into Resolve and down-sampling using Resolve’s 32-bit color system? I’ve tried just bringing my 4K footage into FCPX and down-sampling to 2K there, but don’t notice any difference in the quality of the down-sampled imagery there. ??

(thanks!)

By: Michael

Michael — Fri, 20 Jun 2014 00:34:27 +0000

Wow, that was pretty mindblowing. I knew that downscaling produced better video than shot at same resolution, but now I know why.

It is pretty ridiculous that considering all that debayering, color discarding and compression shenanigans, you have to shoot at 2,5K or 4K to get “true” 1080p in the end via downscaling.