What is Background render ?

[pookitoo]

Hello, I use Final cut since some time but I don't understand what is this background render that take so much space on the computer and I need to clean sometimes (if not it's take all the space in my disk).
Someone can explain to me please ? Because in luma fusion on iPad I don't have / need this .

 

[Gwendolini]

Rendering is the process of creating temporary video and audio render files for segments of your project that Final Cut Pro can’t play in real time. When you add effects, transitions, generators, titles, and other items that require rendering for playback at high quality, the render indicator (a light gray dotted line) appears below the ruler at the top of the timeline.

from

Background rendering in Final Cut Pro​

You can disable background rendering in the Settings of FCP.

You can also have the cache (where the rendered files go to) outside the library and even on a different drive (to have a dedicated SSD or HDD just for cache if you want): View and set storage locations for your library

 

[pookitoo]

thanks but what luma fusion on iPad doesn't need to render the video to show me the result with the settings ? and why in final cut when u want to edit video from my iPhone, I 'm in HDR wine gamut library, when I want to apply a lut it doesn't work very well ? I start to understand that the dynamic and color range are not the same but ...

 

[Gwendolini]

thanks but what luma fusion on iPad doesn't need to render the video to show me the result with the settings ? and why in final cut when u want to edit video from my iPhone, I 'm in HDR wine gamut library, when I want to apply a lut it doesn't work very well ? I start to understand that the dynamic and color range are not the same but ...

Luma Fusion does need to render as well, according to the manual: https://luma-touch.com/wp-content/uploads/2020/07/LumaFusion-Reference-Guide.pdf

Maybe you don't just see it. FCP does show you the result without rendering, it just might not be able to playback the timeline in real time due to many effects and such.

As for the iPhone issue, I don't know about that, as I use Rec 709 and no HDR footage yet.

 

[e1me5]

LUTs are mathematical conversions with specific inputs and are not designed to be universally compatible with all kinds of footage. Usually LUTs are made for rec709 footage or for specific Log kinds of video. HDR is rec2100, that’s why you get weird results.

 

[dandeco]

I have found background rendering useful in FCP X, especially since I liked that feature in pre-2007 versions of iMovie, and in Pinnacle Studio for Windows. Though I do clean up/trash the render and proxy files at least once a month to conserve storage space.