Premiere pro & A7iii Banding

Banding with 8 bit 4:2:0 is just waiting to happen. Sadly. You barely have enough levels to cover the visible black to white tonal range to begin with ... then the camera throws out half the color data to compress the media. That means that nearly any significant change of tonal ranges will show as banding in large areas of low tonal variance and low texture.

If that rig can record formats that are NOT long-GOP, like some form of All-Intra ... that would be a help for you right there. Recording in long-GOP format/codecs just exacerbates things.

That said ... after getting the media into Premiere ... first, very few LUTs are usable with media on the edge of banding. As colorists put it, LUTs are the dumbest math out there, and prone to crush darks, clip whites, and/or cause banding if the media isn't "perfectly" shot for that particular LUT. And by the time you've sorted out which "look" of a LUT you want to apply, I've already graded the shot and moved on.

Do very small adjustments for tonal changes with any one tool. Use several different tools in concert to make your total tonal change ... this will minimize both banding and induced artifacts. Not eliminate, necessarily, but ... should reduce the problems.

So say raise the Highlights slider in the Basic tab only a very few points. Do a micro adjustment with the RGB curves to raise the upper mids. Do a very slight up motion with the Color Wheels mids & highs luma sliders.

Do it the above way, rather than using any one tool to make the whole change of lifting the upper mids/highlights.

And the same with any color change ... use multiple tools in micro amounts.

Consider duplicating the clip up a track ... using Alt/drag. Then add a Lumetri layer on the upper track. Go into the Effects Control and set the Opacity Blending mode to Overlay or Softlight, maybe 20-30% opacity. Do some of your changes on this layer.

I used this to do a rescue grade on a drone shot with a bright cloudy sky and darkish, low-saturated landscape. And also for an office interview with a large window right behind the subject. I had to lift sections of his face, especially the eyes, and ... do something with the horrid blown out window behind him. He turned out pretty useful. The window ... the best that could be done was "Wow, that's not nearly so awful ... ".

Plus adding a touch of "grain" (sort of a film-grain form of dithering) ... from the Effects panel, type 'grain' and drag/drop Noise HLS. Set your program monitor to 100% to view grain as you're setting it ... start with Hue and Saturation at 0, Lightness at 20, Size at 1. Play with the Lightness and Size settings, then go back to full-screen image and play back a section. This can also help hide/mask banding.

Neil

sometimes neatvideo can reduce some banding as it supports a smart luma blur.

you can also try abstaining from luts and graded manually. then grading luma first, before using hue vs lum tools as its a lot easier on the pixels to align gamma globally. also, enable maximum bit depth if you're not grading to enable 32bpc color and stay away from 8 bit effects.

sometimes shooting with a pro-mist filter can help too.