sTrying to understand Premier color space handling compared to Resolve

[James5FC9]

Hi all. Im having a problem finding any documentation on this so I just thought I’d ask. I’m trying to understand how Premiere uses color spaces. I have a project shot on a GH5 and edited in its native h.264 and when I went to color grade it in Lumetri the black levels are all clipped a bit above zero to start and stay clipped when I raise them. But I made a ProRes file in ME from the h.264 and when I bring that back into Premiere the black level do not clip until I try to raise them (they extend beyond zero until I raise the black levels then they clip flat.)

H.264 normal

ProRes file Normal

 

ProRes file after raising black level

 

Now the reason I made the ProRes file was to try the clip out in Resolve and sure enough I can raise the black level in Resolve and they do not clip. 

Same ProRes clip, left Resolve right Premiere both after raising black levels

So what I’m trying to understand is this what is going on here? Is it just the way Premiere works or am I messing something up here (I hope I'm messing something up!) Is there something Premiere is doing to the footage that Resolve doesn’t do or is there something that can be changed in a setting? And what is going on with the h.264 file compared to the ProRes?  My Premiere settings are Rec709 for both the footage and the sequence and in Resolve the DaVinci Color Managed to Rec709

Sorry for the long complex question but I'm trying to wrap my head around how Premiere handels color spaces before I start this color grade.

Thanks in advnce for any insights!

[R Neil Haugen]

My first guess is the camera is using "full range" rather than legal range to encode those files. Which is wrong behavior, though several camera makers do it for the marketing hype in sales.

The exact same data is encoded to either legal or full, it's just how it's encoded that changes. It's a stupid ancient "thing" that was once needed, and it would be a right pain to change it at this time ... so it seems we're stuck with full and legal.

But you do need to use them correctly according to actual professional standards. YUV media ... technically Y/Cb-Cr ... is supposed to be encoded in "legal" range. RGB media, typically 12 bit and better ... should be encoded in full range.

All current monitors and systems will normally 'see' and work with them correctly ... and all legal range media is correctly displayed as full range if you don't muck up the settings.

[James5FC9]

Thanks Neil! That would explain a lot of the initial behavior but I’m still trying to figure out why I can get so much better details out of the blacks in Resolve when I do the grade. Premiere just seems to be crushing the blacks where I’m seeing a lot more detail in them from Resolve? 

Could it be a case where Resolve can use the data that falls outside of legal range where as Premiere just throws it out? I need to do the full grade in Premeire but I did a rough test in Resolve and can not get them to closly match even in the basic adjustments.. 

[R Neil Haugen]

First, get that camera set correctly so you don't have this issue going forward!

Resolve has about every possible control option for the users, including things colorists feel totally screw up nearly everyone using them. Just ' because you can ' is not a good reason for doing something. Is it correct, and ... is it wise?

Next, there are a few presets in the Effects panel for full to legal and legal to full conversions. Drop the full to legal on the selected clips in the bin, in the Project panel, and it probably fixes this issue for these clips.

[James5FC9]

I’m not sure how the cameras are setup, I don’t have access to them and wasn’t on the shoot. But adding a Full to Legal effect made things better so thank you. 

I’m still getting much better results out of Resolve and I think it has more to do with how Premiere handles adjustments versus resolve rather than the working colorspace as I originally thought (although I’m still not 100% clear how Premiere handles color spaces). After testing it last night It seems like Premiere will squash blacks (or any luminance group) as you raise or lower them rather than preserve the details like resolve does. So rather than raising the blacks as much as I want to I have to push the exposure up on the whole image then the blacks slightly then bring down the meds and highlights, just to get the same adjustment I do in Resolve by raising the Lift. I’m not sure if this is how Premiere is supposed to work but I can at least get somewhat close to the look done in Resolve and move forward. 

But thanks for the help! As someone who edits in Premiere and color grades in Resolve this current project is really making me mad at Adobe and the whole way Lumetri works and interfaces, ha ha. 

[R Neil Haugen]

Which controls were you using in Lumetri? As someone who works for/with/teaches pro colorists, I've been working in both Pr and Resolve a decade and change. With some pretty high-end colorists. I teach them how to work in Premiere if they must, btw.

The Basic tab Blacks control is kind of a swinging door hinged around what, 12 or 15 IRE? Use it only to 'trim' the bottom couple values, do NOT use it to raise or lower general Shadow levels. In the Basic tab, move the general shadows up/down with the shadows control, only tap the Blacks for a couple points adjustment at the end if needed.

The Color Wheels tab Luma sliders are really better for most change of shadow values, they're a standard Lift operation, exactly the same as the Lift wheel in Resolve.