FS7: Premiere and slog LUTs

L

Lenilenapi

Carbonite Member
I'm posting this for my client who is cutting something in Premiere CC that I shot on the FS7- UHD Slog3 CINE EI at 1250 ISO. Some of it may have been at 1000 ISO.
Its coming in at 2000 ISO and looks overexposed ( makes sense) however says that he doesn't seem to be able to bring the exposure down. I don't Premiere at all so its difficult for me to troubleshoot. The client says the controls he would usually use for RED footage are greyed out.

Can anyone help me help him. I realize its kind of vague. Maybe just pointing men to a good discussion of Slog workflow in Premiere. I was thinking of sending him Alister Chapman's LUT's designed for one stop overexposure.
 
Hi Len

I usually use the fast colour corrector to get the exposure back to where I want it.

Ask your friend to use the levels section of the effect and adjust the output white bottom slider on the right hand side.
If he keeps an eye on the waveform he should see the clipped values recover. Hope this helps.

Surinder.
 
In Davinci Resolve - grade clip (use slog3 LUT on output)
From the DR color timeline - right click on graded clip - export LUT

In Pr CC - File - new - adjustment layer
Edit adjustment layer in Pr timeline
Add any Lumetri Effects look to adjustment layer
Double click timeline effect to load into effects
right click Lumetri & " load LUT" from Resolve
 
What I usually do is open the footage in Catalyst and export a quick lut that has the exposure correction and lut of choice which is usually LC709A lut then pass that along to post as a starting point so my footage looks as intended and they can grade from there.
 
2 excellent alternative tips guys.

I've just find my machine bogs down a little too much with Luts applied via Lumetri.
With the fast colour corrector I can still editing at half res 4k XAVC I.

Also if you like to fiddle with the look while editing as I do. I find quickly cutting and pasting the fcc effect and minor tweaks works really quickly for me.
 
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Thanks guys . I found a tutorial online explaining Lumetri in Premiere so at least I understand the workflow now and will be able to understand his problem better . He's a very experienced editor and can't use Resolve for this because of some technical issues that has to do with his effects flow . He said his corrections in PP were greyed out when he applied 709 type A but I need to check in again w him because it's his 1st time w slog in PP .

Frame Farm - by exporting corrections from catalyst are you losing the flexibility of SLog for post ? Do you export w LUT applied or just tweak the flat slog file .? Also since that requires a transcode , do you export as ProRes or DNXHD rather than recompress XAVC ?

at the moment he just needs a useable looking exposure for a work in progress screening to client and was happy w the look in catalyst when he set ISO to 1250 as shot . So maybe you method would get him through the screening until we trouble shoot further .
 
Lenilenapi said:
Frame Farm - by exporting corrections from catalyst are you losing the flexibility of SLog for post ? Do you export w LUT applied or just tweak the flat slog file .? Also since that requires a transcode , do you export as ProRes or DNXHD rather than recompress XAVC ?.
Click to expand...

I don't touch the original files. I just take advantage of the fact that Catalyst reads the meta data on EI exposure and export only a lut to be applied to the original Slog in the edit software of choice. Takes a few clicks to get a nice exposure lut to work with while editing then I will go back and tweak later if I have the time. No transcoding or degradation to the original XACV-I.
 
Are you talking catalyst browse or prepare ? Can browse export a LUT you design.? . I should be able to do the same in Resolve right ?


By the way - was I too timid in only going to ISO 1250 to mitigate slog3 noise ? I noticed that alister Chapman uses 800 . Will they still need to add noise reduction ?
 
Lenilenapi said:
Are you talking catalyst browse or prepare ? Can browse export a LUT you design.? . I should be able to do the same in Resolve right ?


By the way - was I too timid in only going to ISO 1250 to mitigate slog3 noise ? I noticed that alister Chapman uses 800 . Will they still need to add noise reduction ?
Click to expand...

I only have the free Catalyst browse to export exposure luts. You can make an exposure lut in resolve but I find Cat browse so easy as it automatically remembers the EI information
 
Beautiful man! Thanks so much. I just found the help files in CB and found the tools menu. I never looked at that before -- duh!
I have been very meticulous on learning the camera and just put off workflow because I was busy with lots of other stuff. This is perfect though and easy for client workflow. I know its really FS7 101 though.
I presume making a LUT for Resolve in CB will create a LUT that can be imported into Lumetri for Premiere?
 
What is wrong with just applying the LUT of your choosing an then just tonig down the exposure with fast color corrector or similar?
Like suggested by @surinder earlier in this post.... it is very quick and easy.... or is there a quality penalty or something i'm missing here?
 
tscav said:
What is wrong with just applying the LUT of your choosing an then just tonig down the exposure with fast color corrector or similar?
Like suggested by @surinder earlier in this post.... it is very quick and easy.... or is there a quality penalty or something i'm missing here?
Click to expand...

I do believe you need to adjust exposure before you apply the lut otherwise it will distribute the bits wrong as it delogs.

I use Catalyst browse to offload footage because it keeps the file structure intact and does checksums. So because I'm already in that program I just click on a clip to load it. Catalyst reads the EI meta data so I just export that with the LC709typeA as a lut for use in my NLE. takes about a minute.
 
tscav said:
What is wrong with just applying the LUT of your choosing an then just tonig down the exposure with fast color corrector or similar?
Like suggested by @surinder earlier in this post.... it is very quick and easy.... or is there a quality penalty or something i'm missing here?
Click to expand...

Reasonable question. I'm not sure why but the client said his color correction settings were greyed out after he applied the LUT. He is an experienced editor but not with slog3 in Premiere. Now I don't know exactly his procedure and have a conversation scheduled hopefully for later today . From the tutorial I saw you want to do that on a level below and thus before the Lumetri level where the LUT is applied. Possibly he tried to apply it after LUT was applied ? Would that grey out the color correction controls though?

This does bring up a question - Should you simply lower the exposure using color correction before the LUT is applied or use a LUT designed for a higher exposure? My impression from reading stuff from Alister Chapman is that adjusting the exposure first actually throws off the relationships of highlights and shadows and you are better off using a LUT designed for the greater exposure like the ones he provides on the web. However he says this is only a noticeable issue when the exposure is much greater than 2/3 stop.

What's happening when you adjust the ISO in CB Browse when using 709 type A? Is it changing the underlying exposure first , changing the exposure after the LUT has been applied, or is it actually creating a new LUT for the new exposure index?. I doubt it is choice #3. What is best procedure though? More to the point , what's best for quick offline files and what's best for final grade and how do you not shoot yourself in the foot for final grade if they are different workflows?

Lenny
 
Lenilenapi said:
This does bring up a question - Should you simply lower the exposure using color correction before the LUT is applied or use a LUT designed for a higher exposure? My impression from reading stuff from Alister Chapman is that adjusting the exposure first actually throws off the relationships of highlights and shadows and you are better off using a LUT designed for the greater exposure like the ones he provides on the web. However he says this is only a noticeable issue when the exposure is much greater than 2/3 stop.

Lenny
Click to expand...

That makes alot of sense indeed.. I've only done minor adjustments so it's been looking fine - but I can se how 2/3 stops could be an issue..
I dont see the controls being greyed out in premiere - though it does give best result done i proper order.. Maybe have your editor put the lut on an adjustment layer instead of on the actual clip - that way he can also lower the opacity if he wants to to down the effect of the LUT - I use that alot especially for the more "creative" LUT'S if I like the feel of it , but its a bit over the top.. Getting off topic maybe

@FrameFarmMedia - great insight - I'll be trying that out...
 
Frame Farm,

FrameFarmMedia said:
Catalyst reads the EI meta data so I just export that with the LC709typeA as a lut for use in my NLE. takes about a minute.
Click to expand...
So how do you export the shot and the LUT exactly . I assume you are not transcoding so do you use "copy", and does that include the new adjusted LIUT info or do you export the new LUT separately using 'Tools" . If the latter, how do you keep the shote and the LUT together?

Lenny
 
Lenilenapi said:
Frame Farm,


So how do you export the shot and the LUT exactly . I assume you are not transcoding so do you use "copy", and does that include the new adjusted LIUT info or do you export the new LUT separately using 'Tools" . If the latter, how do you keep the shote and the LUT together?

Lenny
Click to expand...

Yes I export the lut separately using 'tools'. If I'm sending the footage off to someone else for post then I just include a text doc that goes with the lut explaining which one is which group of shots. If its obvious i also try and name the lut something that will make sense like Day1 Exterior lut or something like that. I still haven't gotten a perfect system but a quick call with the post house or the included text doc gets the message across.
 
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