FCPX Export Bitrate Poor - How to fix ?

[soamz]

I shoot with sony a7s2 and gh5 whose 4K files are shot at 100Mbps or even 400Mbps too.
When I edit on FCPX and then export to 4K.
Here is my export screen - http://prntscr.com/i17zrb

I can see the exported file is just 29Mbps bitrate which is very low quality, even though my eyes cannot see the downgrade in quality, but I guess Im still losing quality because it doesnt look very very crisp when I watch my videos on 4K monitors or 4K HDR displays.

So, what am I missing ?

How can I get my bitrate high in export profiles, as I hate compromising with my export quality as I upload to Youtube and Vimeo both.

Let me know, thanks.
Im on latest FCPX FYI.

 

[BeechFlyer]

soamz,

29Mbps is not a terrible bitrate for final delivery of 4K, even though recording and intermediate formats use higher bitrates (for different reasons). If you want to deliver with higher bitrates for even better quality, my understanding is you'll need to get Compressor in addition to FCP to adjust the export settings.

As an experiment you could export with a better video codec (ProRes) and see if that looks any better on your 4K monitor than the H264 export. If you can see a noticeable difference, playing with higher H264 bandwidth would be worthwhile - if not, what you see now is likely the best you'll get.

 

[soamz]

Ok I will try that.
Thanks.
Will look at compressor too.

 

[Unami]

29mbps is an o.k. bitrate for 4k. I export 30mbps in 4k for my customers. and it does look crisp. have you compared your rendered clips with the original footage on your tv?

the 150 or 400 mbps are encoded on the fly, whereas the 29mbps should be a multipass encoding (so the compression algorhitm looks at the whole file and determies the best compression before it actually starts the compression), so a lot of those 150mbps in recording is there to compensate for not being able to look into the future. furthermore, the gh5 records in 10bit 422, whereas your 29mbps are probably in 8bit 420 so there’s significantly less color and luma information there, which alone could warrant a size reduction that big. (the 400 mbps oprion is all-i, whereas the 150 mbps or the 29 are long-gop, so there goes the rest of your bitrate)