GH5 vLog Yellow Banding

[xfan10]

Hi, I am considering using Premiere as my primary editor but I have noticed an issue in Premiere with my GH5 VLog footage (8bit+10bit) and I am wondering if someone can help me find out if either my camera is defective or if its a bug that will eventually get fixed in Premiere. It's yellow banding that occurs mostly on white surfaces. And I only notice it in Premiere when using LUTs in Lumetri Color. I am using the GH5 LUT that Panasonic offers for free to GH5 users. But I notice it pretty much in any LUT, some more than others. The interesting thing is I do not see this phenomenon when using either Magic Bullets Colorista or Looks when loading LUTs within Premiere. Nor do I see it in Final Cut X when loading a LUT in Color Finale. So I am just making sure its not the camera while I have time to exchange it. I am linking to a 1 second vlog file that if someone can view and see if they see the same thing and may notice this phenomenon in their own files. I have also attached a screen shot of it without saturation and with a lot of saturation to show where to look for it easily.

Screen Shot of VLog_to_V709_for35_ver100 w/ No Adjustments

Screen Shot of VLog_to_V709_for35_ver100 w/ excessive saturation

1 second RAW VLog 4k video file

https://www.dropbox.com/s/ngp8tqsoaavlpna/banding.zip??raw=1

1 second encode VLog 4k Video file with VLog_to_V709_for35_ver100 LUT

[Kristian Gabriel]

Log-encoded footage is great for giving you more to work with in post-production when used with real raw footage. The GH5 does not shoot "real" raw--so while V-LOG-L does give you more latitude in post--it will not be as much as raw. I own the GH5 and have seen this banding issue primarily with low-contrast footage using V-LOG-L. I'm not saying that its not a hardware issue, however I have experienced this myself and heard of others with this issue using V-LOG-L. It seems to fix the footage to record to an external recorder that can capture in the Prores Format. I've shot excellent professional video with the GH5--but its not without its faults. Many of us are waiting for the "soon" coming 4:2:2 10-Bit 400mbps codecs released any week now. Many believe this will solidify this issue. Until then--some are not using V-LOG-L for critical projects right now.

Options:

• Make sure all Adobe Premiere Resolution switches are set to full
• Experiment by turning the HIGH QUALITY PLAYBACK in Program Monitor settings
• Transcode to Prores 422 HQ or Prores 444 or Cineform 12-Bit and retry everything above
• Get external recorder that can capture in Prores, etc.
• Wait for soon coming 400mbps codecs to be release (end of Summer 2017)
• Don't expect a lot out of V-LOG-L currently until the updates happen and shoot with this in mind.

I know it may not be much of solution--but those of us with GH5's are in this together--and hoping for these next firmware/software updates. Maybe someone else will come up with alternate solutions--but this is my experience. Good luck!

[xfan10]

So are you saying you have seen similar banding only in Lumetri Color but not in Magic Bullet or Final Cut? If so, do you know where I might find these discussions? Because it seems since it was only happening in Lumetri Color, the the bug was in Lumetri Color, but you are saying it's in the firmware so why isn't this issue happening in Magic Bullet or Final Cut if it's the firmware?

Also, doing some more search I found this post and it seems like a similar issue with what I am seeing.

https://forums.adobe.com/thread/2231259

You can se in their screenshots as you scroll down some, a yellow type of banding. Is anyone else experiencing this with their GH5 using Lumetri Color and LUTs?

Thanks

[R Neil Haugen]

In that long thread were about 3 different ... if not more ... issues. Some Mac-centric, and some due to migrating a project forward with LUTs involved, and needing to remove/re-apply the LUTs in the new version. And maybe a couple other things. So it's not particularly helpful with the issue you seem to be having.

To do a real good quality output in a log format takes a lot of data in the media file out of the camera. And something can be technically "10-bit" without having near the data to record in log & then try to do much in post. The GH4 had this issue ... simply too "thin" a data stream into the files to properly work as a log media in post especially for heavy grading.

Which is why Kristian's comment about waiting for the GH5's log use until the firmware for the 400Mbps recording is released is appropriate. That ... hopefully ... will finally give us a GH that can really be professionally useful in log format.

As to the Colorista & FCP varying in their display ... due to the nature of the attempts to match media & software, one program may at times work better with a particular camera's media than another. The GH5 is out on the bleeding edge of compression to get that much data processed & recorded to media in such a small form camera. The software folks have all been struggling with it, and it seems a FCP and Resolve are both handling GH5 media slightly better at this moment ... with certain media settings/styles & workflow combinations. That's due to change at any moment ... it's the nature of the business.

Have you tried creating your own LUTs for working the log back to 'standard' Rec709? I've normally been happier with the LUTs I've created for such things than the manufacturer or 3rd party LUTs. I started doing that just to 'understand' how they work, and well, liked my home-cooking better. But wondered if I was crazy, of course. Talked with a colorist friend, and ... he downloads the manufacturer's LUTs for all the cams he's working with in his regular run of clients ... plays with them using gradient graphics, looking at various curves & such ... and normally, makes his own.

In fact, he'll start a project using his own "base" LUTs for different cams, and modify them to best fit that project as he goes along. Says about half his normal peers do likewise, about half pretty much stick to straight stock LUTs outta-the-box.

Neil

[xfan10 · Accepted solution]

Hi Neil, thanks for the response.

Well I think I solved the issue, it was a tidbit in that post the set my spidey senses off. Metal. I do use a Mac and I was using Metal as the GPU accelerator, and sure enough, as soon as I switched it back to OpenCL or Software Only, that banding in Lumetri Color disappeared. So I can confidently say there is a bug/conflict with Lumetri Color and Metal Acceleration. Now why would a preview accelerator effect the actual encoded footage, I do not know. But it does. It affects the preview in Premiere and affects the output when using Metal. This might explain why it hasn't been discussed much since it's Mac only.

May I ask what method do you recommend when creating your own LUT?

[R Neil Haugen]

Metal, eh? Good to know.

Using LUTs through Lumetri doth mean the GPU is now heavily involved in the process of delivering your screen content. If between the GPU, drivers, Lumetri/PrPro, and main OS/system, there's some oddity going on, you will see it. And there's been a lot more Mac GPU issues since El Capitan came out. Sadly.

I'll take a quick bit of footage if I've got the camera handy (normally I do) in a controlled setup, or from a "reliable" source, produced in that camera's log setup, and hopefully a similar shot 'normal'. Plop them on a sequence in PrPro or over in SpeedGrade (or a few times, I've used Resolve; know my way around Lumetri & SpeedGrade better though). Add another graphic I've made that's a series of 15 boxes of black-to-white in step-wise fashion on the left, and a 40-step grayscale ramp on the right half of the image.

Now put an adjustment layer across all three "clips". I can then work on the layer, and see both what this does to a very "known" clip of standard and complete ranges of values & tones plus on a varied gray-scale pattern.

Then, I start looking at the scopes of the log-produced media, RGB Parade & Waveform, probably both Luma & Chroma modes, along with Vectorscope YUV. See what's there, and what's missing. Frequently then I start working with curves, seeing how close a simple Luma curve correction comes, then modding the R, G, and B curves as necessary. This handles most of the work.

Then trying out some saturation tweaks as seems useful. Maybe increasing/decreasing the general saturation or even that of a specific color in the shadows, mids, or highs might be a nice addition. Most of the time, any Sat work is pretty subtle ... if needed. (Done in the Secondary panel in Lumetri, either a secondary or a Curves/Sat layer in SpeedGrade.)

Check how close that work comes to the manufacturer's LUT, if I'm interested.

And export as a .cube when I like the result.

Takes 5-10 minutes, most of the time. Well, took a bit longer the first couple times, but after that, it gets a lot faster. Really.

Neil

[djambalawa]

I filmed the full moon rising a week or so ago..  and i have quite a bit of banding (see below).  I sped up the footage a bit and used a lumetri.

Full moon rising at Fogg Dam - YouTube

Filmed in camera UHD/60p 150mbit/s.

So recording to an external recorder at 4:2:2 would've prevented this?

[R Neil Haugen]

I don't know which settings you were using on that, and of course, viewing via YouTube I'm not sure what YouTube may have done to your upload.

From my well-calibrated screen, the blacks were simply not ... all that dark. So it could be the YouTube mashup of PrPro tonality hit, and displayed your clip in 16-235 manner. It was very ... surprisingly ... low in contrast. And yes, with a lot of banding.

Neil

[djambalawa]

Hi Neil - I should mention it was moon rise and the sky was not black at all.. it was twilight..  the sun had just set behind me..

It was a UHD upload to youtube with 40mbit compression...  which normally looks really good with my normal footage.

So yeah a very low contrast scene which i guess is bad for this banding apparently..

[R Neil Haugen]

What settings ... profile & adjustments ... did you have set on the camera?

Neil

[djambalawa]

Was shot in v-log..  i don't remember other settings but it was probably shutter priority, 1/120sec, ISO400.  Might have dailed in a little neg exposure adjustment not sure..

The moon was very faint against the twilight sky..

[R Neil Haugen]

I've not got much GH5 media I've worked with, but especially if you're dealing with a moderately low-contrast scene to begin with, I don't think I'd bother with the v-log. The whole log thing is to keep as wide a dynamic range of data as possible ... but it's rather "thin" media unless you've got full 4:2:2 10-bit. Trying to expand a narrow-contrast scene out with 8-bit media that was "squished" together in that Panny GH-log ... not the best thing to be doing to it. Personal thoughts, though, and again ... I've only worked a bit of GH5 media.

Now, I hope to change that in a couple more months ...

Neil

[TheIMR]

xfan10 - thank you SO much!  I was having exactly this problem and had basically resorted to correcting footage from scratch.  No I can use LUTs again!  Really appreciate your working this.

Mike