After importing, I can turn off the applied lut on individual clips, but it takes 5-10 mins for FCPX to remove. I am importing flat clips and wish to work with them as flat clips so I want to stop the dreadful automatic lut from being applied to everything I import. Help please.
You easily remove the FCP auto-applied LUT by selecting all the imported clips, then in the Inspector's General View, Info tab, set Camera LUT = None. You can change 500 clips in a single procedure. I'd edited libraries containing thousands of S-Log3 clips, and I've never seen it take significant time to turn that off.
What you may be observing is the time to regenerate the *thumbnail images.* That does not indicate when the change goes into effect. If you set Camera LUT = None on hundreds or thousands of clips, that should be immediate. If you doubt this, click on any of the changed clips and examine what the viewer shows. The viewer shows the current, instantaneous state. The thumbnail images in the filmstrip are a lagging indicator because it may take time (depending on CPU, disk, memory, etc) to generate those updated thumbnails.
You easily remove the FCP auto-applied LUT by selecting all the imported clips, then in the Inspector's General View, Info tab, set Camera LUT = None. You can change 500 clips in a single procedure. I'd edited libraries containing thousands of S-Log3 clips, and I've never seen it take significant time to turn that off.
What you may be observing is the time to regenerate the *thumbnail images.* That does not indicate when the change goes into effect. If you set Camera LUT = None on hundreds or thousands of clips, that should be immediate. If you doubt this, click on any of the changed clips and examine what the viewer shows. The viewer shows the current, instantaneous state. The thumbnail images in the filmstrip are a lagging indicator because it may take time (depending on CPU, disk, memory, etc) to generate those updated thumbnails.
In both Resolve (if using RCM) and FCP, it will auto-apply a log-to-Rec.709 LUT or transform when using certain codec and container types that have sufficient metadata to identify the clip's color space. E.g, on Sony cameras that support the MXF container, it does this. On Sony cameras that only support the MP4 container, it will not. For those, you must manually select the LUT/transform or manually flag the color space. It's probably similar to other camera brands.
For cases where the colorist wants different processing than the auto-applied transform, that can be turned off for the entire batch of clips in seconds, whether they are in the Event Browser or already edited into the timeline.
The behavior is an increase in execution time when adding or removing FCP built-in LUTs that scales quadratically with the number of clips being adjusted. Back on FCP 10.8.1 and Ventura 13.7.8 this was over 10x faster than FCP 12.2 on Tahoe 26.4.1. I don't know when it got worse. Here are some basic numbers:
Approx. Elapsed Time to Add/Remove Camera LUT
on Sony MXF clips, FCP 12.2, Tahoe 26-4-1, M1 Ultra
50 clips: 16.8 sec
100 clips: 52.6 sec
200 clips: 213 sec (138 sec on FCP 10.6.10, 145 sec on 10.8.1)
Approx. Elapsed Time to Add/Remove Camera LUT
on Sony MXF clips, FCP 10.8.1, Ventura 13.7.8, 2017 i7 iMac 27
50 clips: 6.4 sec
100 clips: 11.2 sec
200 clips: 31 sec
It is caused by a complex interaction between the FCP "Flexo" framework and the macOS "Foundation" framework. The causal factor in FCP has long existed, at least back to 10.6.10.
In software engineering terms, it is called a "structural O(N^2)" or sometimes a "a hidden or accidental O(N^2)," where execution time increases with the square of some term. That can be seen in the above table, where execution time to add or remove LUTs increases roughly with the square of the number of clips adjusted.
This is often not the result of a single inefficient algorithm but rather of how different layers interact. This is the case with FCP and macOS. There is a code path in the Flexo framework that has a quadratic cost, but it previously wasn't that bad for the end user. However, it was calling a function in the macOS Foundation framework, which itself became significantly slower at some point. That slower behavior did not significantly impact most apps. However, because the FCP code path handling LUT add/remove called it a lot, this showed up dramatically in FCP.
Even on FCP 10.6.10 on Ventura 13.7.8, the time to change LUTs rapidly escalated with number of clips changed, just starting from a lower number than FCP 12.2 on Tahoe 26.4.1.
As described by bayoyong2, the real-world impact on FCP is major. It basically means you cannot freely import lots of clips (which often get auto-assigned LUTs), then freely drop those LUTs in a single batch. It will cause an FCP "beachball" hang which varies with the square of the number of clips adjusted. It rapidly becomes impractical, plus some users would think FCP had locked up and would force quit or take other steps.
It's tempting to say "FCP should add a bypass feature so it only adds LUTs on import if you enable the feature." But FCP has long had automatic LUT feature, and adding another config option because the feature is basically broken isn't the best way. I can't imagine Apple ever doing that.
I have to study this more, than I will probably file two bugs, one on macOS for the Foundation framework and one on FCP for the Flexo framework's handling of multi-clip LUT add/remove.
I don't think this is a simple fix, even if done entirely in FCP, because it would seem to require a significant rewrite of some Flexo framework code. See below Instruments traces.
I'm more curious how you get the LUT applied automatically on import, as I've never had that happen to me. I shoot in Panasonic VLOG. Granted I usually shoot on an Atomos Ninja so that may play a part. But even when I shoot straight to an SD card in the camera for a higher frame rate (something Atomos doesn't support) I still don't get an auto-LUT applied.
I'm like you though, I'd prefer it doesn't auto LUT anything as I feel I can get better results without the LUT.
Thanks for the help! I wouldn't call turning off the LUT easy, though. If I have 100 clips (fairly typical on an import), it takes 3-5 mins for Final Cut to remove the LUT after I ask it too ... when I didn't want it on there. I would say most colorist have their own LUT's and don't want Final Cut to decide to add something that takes 3-5 mins to undo on every import ... which is the reason for the thread. But I do thank you for explaining how it only does it to certain files. I will add feedback to Apple. TY.
This behavior seems to be about 15% or 20% faster on Tahoe 26.5 vs 26.4.1 (Using FCP 12.2 on M1 Ultra Mac Studio), but that's not nearly enough to make a practical difference. It needs to be at least 10x to 20x faster, like it was in Ventura. Until that level of performance is restored, it will be difficult to make batch changes to FCP built-in LUT settings on more than about 50 clips at a time.
Thx. I know how to remove them. I’d rather FCP not add them in the first place.
Apparently it has to do with the camera you use.
There is a possible issue that I am investigating.
I see what you are saying about the thumbnails now. But if it didn't add the LUT, it wouldn't need to repopulate the thumbnails. Thanks for the help though!
Thank you joema for your amazing debugging and reporting abilities!
how do I stop fcpx from automatically applying a lut to everything I import?
