Premiere colorspace - how does it interpret inputs? Varicam footage.

[DwarfVader]

I have Varicam footage saved as MXF (AVC-I 4K422 and AVC-I 2K444) video in V-Log format, in the V-Gamut colorspace, and the same footage recorded as RAW Cinema DNG sequence. I would like to use Premiere Pro/Adobe Media Encoder/After Effects to convert this footage into a format readable by The Foundry's Nuke, preferrably EXR.

When I process it with other software, like DaVinci Resolve, I get mathematically expected values. I have set up Resolve to work in ACES and everything makes sense. However, Premiere Pro is just a bunch of unexpected behaviours for me. However, I am in a situation where getting this to work with CC software is preferrable.

Firstly, when I import my MXF (which contains V-Log video), its appearance changes. Same in After Effects, and Media Encoder. The contrast increases and gamma decreases slightly. However, when I import a DPX sequence with the same contents as the source video file, it remains unchanged, and looks like V-Log should. Does Adobe Premiere/AE/ME apply some LUT at its own discretion? How can I know what it does? What's with the black box? As it is, using it to convert or edit Varicam V-Log video is not really possible. It behaves like standard dynamic range footage, and I am not even convinced it's converted out of Log besides a small contrast adjustment. Exporting it into Nuke is also useless, because when I convert this parody of a V-Log into scene-linear, the resulting values are nonsensical (0-50.0 instead of 0-16.22).

Furthermore, I know that Premiere Pro works internally in Rec.709. Does it clip wide gamut footage? Apply tone mapping? Or does it completely ignore the imported footage's colorspace and simply processes the RGB values given? DaVinci Resolve applies input transforms and lets me choose them. Here, there's nothing, not even in the Interpret Footage menu.

When working with Varicam's RAW footage, I have better results. Importing Cinema DNGs and exporting EXRs is simple, the only thing that is... they're underexposed by prcisely (approximately?) 4.03 stops. Once I adjust for that in Nuke, everything works as expected mathematically. Why is that? I have not made any adjustments to it in Premiere. Not only that, if I do up the exposure in Premiere by the same amount before export, the result is a flattened overexposed SDR-looking mess.

What is going on here, and can I know what Premiere does to my footage when I import it??

[R Neil Haugen]

I can help with some of this.

Pr takes all media and essentially converts to 32 bit float for calculations while processing it. There's a lot of confusion in how it "sees" media partly because of the way the scope right-side scales are set, 0-255. That is not how it "sees" the media, it's a representative look at how the media scales to a screen. (I think this might be an effort not to confuse untrained editors or something.)

If you go to the scopes control area lower right of scopes panel, un-clamp, then right-click and set color space as Rec.709, Waveform to YC, you will have a left-side scale of 0-100 IRE lined up across a right-side scale of 16-235, standard video-levels display. This way at least you will see something that makes sense.

Pr is Rec.709 and expecting an sRGB screen at gamma 2 4 or 2.2. So that is what is generally happening.

As to your media  ... there are some formats from some cameras that Pr automatically applies a correction LUT or set of default parameters to on import. To check this drag a clip to a blank timeline and perhaps go to the Color workspace. Near the top of Lumetri Panel are two side by side options, the left says Master or Master clip. (Probably available in Effect Controls Panel but on my phone going from memory.)

Click the Master Clip option and you can see if it is applying anything to the media.

Neil

[DwarfVader]

Thank you Neil. The advice regarding the scope is very useful.

Unfortunately, there was nothing in the Lumetri Color that affected my footage, not under Master nor the timeline-specific tab. For a good measure, I have turned all of the tabs off. You can see the difference below. Here is the proper image, a flat log (read from pre-converted DPX):

And here is how Premiere displays the MXF in the same timeline:

You can see the increased contrast. The values in this log should not go above 0.9, but they do. This looks like a small difference here, but if you've worked with log you'll know it makes a big change at the end.

So unfortunately my problem is not yet resolved.

As a note, Panasonic lists Premiere Pro among the software that supports teh Varicam workflow. Meanwhile Adobe's supported formats list is a little more vague, mentioning "P2 cameras and AVC Ultra". Varicam does fall under the AVC Ultra category to the best of my understanding, but there is no particular list of supported cameras that I've found, nor an explicit mention of V-Log and V-Raw.

[Jim_Simon]

I am in a situation where getting this to work with CC software is preferrable.

To be honest, your best option might be changing that.  Adobe's color management is woefully behind what Resolve offers.