Lumetri Effect huge input lag in PrPro 25.2.0 build 57

Transform and look in one LUT ... I can see of course where the attraction would be, but ... speaking in my colorist mind-set, that's an opening for troubles also.

I work for/with/teach pro colorists, and most of them went to algo based transforms log->linear as soon as they tested them and found them both safe and stable. That said, you will find some productions where the Director or DP insists on a LUT based process still.

Even then, some of the colorists I've talked with who get hit with that occasionally take the LUT, test to determine exactly what it's doing, and build either a node tree in Resolve or a DCTL that starts with the built-in transform and applies the look changes also. Visually nearly identical, but safer for all media used. 

I would suggest spending maybe a day with a number of test clips, seeing what the tonemapping algo does, and building the Lumetri presets to dump on them in the bin, would be a better process moving forward.

I don't use nearly the Adjustment layers I used to. But still, one very efficient method is to use their auto log/auto tonemapping tool, then have Lumetri presets for each camera type's media to finish the neutral/gray-point/tone-curve stuff. Apply that to all clips of each camera in the bin, so it affects all bits of any clips anywhere. "Source effect" is an awesome bulk tool.

Then put the Look in an AL above the clips in the timeline. Alternatively, apply the Look in a second or so Lumetri instance on all clips in the timeline, another bulk approach. But as I use a Tangent Elements panel, and the devs have never fixed the issue where all control panel work is appled to the FIRST Lumetri of any track!!!!!!!!! (yes I'm still upset about that!!!!!!) I would use the AL in this case, personally. So I can use my panel.

So ... drag/drop clips to the timeline, everything is pretty neutral and nearly matched tonally also ... make a quick pass to minimize any visual changes, then turn on the AL with the look to make sure all the clips 'fit' that look. Modify if needed to make 'em fit.

Yeah the main thing holding me back from using it is nearly all my looks / luts are based around converting the footage from LOG and creating a film look some type of look in one step. They are often a creative lut and a transform lut so they don't really jive with the new paradigm. I haven't been editing as much so I haven't really wanted to reinvent the wheel just yet. Maybe once the fully push the color pipleine into stable premiere I will tinker more. 

Yea, that processing thing you mention is ... interesting.

You're correct about LUTs being prone to clip or crush. That's heavily discussed by all colorists and colorist training, of course. Where you apply a transform LUT is rather important.

Before their new color management options, I always applied any transform LUTs in the Creative tab slot, so I could trim the clip into the LUT through the Basic tab controls. Which are of course processed before the Creative tab ... as nearly everything is top-down in Premiere processing. Including the Effects Control Panel list of applied effects to any clip.

Well, as long as tracks aren't involved ... as if so, then it's top down on the lowest track within that track. Move up to the next track, top down within that track, move up ...

But with the new CM stuff, I rarely use any conversion LUTs. The tranform algorithms are actual, complex math, not just a text chart of RGB value replacement, which is all a LUT is.

So the transforms will not clip or crush your pixels. Which is in itself a HUGE improvement.

Set the auto detect log to on, set auto tonemapping on your timeline, the conversion is now mathematically handled specifically to get all data safely into the new color space/dynamic range.

As with any conversion LUT, the algo's are intended as a first step, not to be the final look. So you use the algo to do the transform rather than a LUT, and as before, probably have presets of Lumetri for your particular media and tastes ... that you apply as you choose.

@R Neil Haugen yes that is how I typically do it. I know there is a wider working space now but I still do things the old way until I can figure that out. In previous workflows applying a lut was more or less destructive and would clip highlights etc. With FS7 footage many shooters overexpose 1-2 stops, aka rate the camera at 800iso instead of the recorded 2000 base iso. 

Long story short, toggling and untoggling the adjusment layer seems to cause app to read all the timeline files again for some reason before showing the image. I notice a lot of disk activity whenever I toggle the adj layer on or off. Something is off in the beta and I hope adobe fixes it before they push this on users. 

Just to make sure Scrozier understands order of operations  ... that log to Rec.709 LUT and other corrections in the Adjustment Layer are being processed after the corrections applied in the timeline.

So you are aware your Lumetri timeline things are applied before the LUT, right?

There is a workaround for the basic panel. Just type the values, don't move the sliders. But there are numerous other things that cause the timeline to freeze like placing an adjustment layer or turning adjustment layer on or off. Seems wierd that Adobe hasn't seen this bug as there are many people reporting it in different threads.

Still not working right in beta. Color correction basically impossible in the basic tab. 

v25.2.0 Build 59 doesn't really change anything here. If i enable/disable the global layer or add a text layer on top of it, Premiere hangs for about a minute until after lots of network activitiy to the NAS.

Did a test on the latest build (25.2.0 - b59..._ Creative and Curves tabs work normally, but any adjustment in the "Basic Correction" tab is horrendously slow. 

Sounds like the same issue I'm having here:
https://community.adobe.com/t5/premiere-pro-beta-bugs/timeline-performance-problems-since-25-2-0-build-50/idi-p/15034753
(ignore the GUI problems, that seems to have resolved itself for now)