XAVC-S 8-bit 4:2:0 is much better than many people think

Samuel H

Samuel H

Major Contributor
I just saw this video, and well, if you think heavily compressed H.264 8-bit 4:2:0 can't be good when you're recording log with lots of DR, well, just watch it.
Another thing they found, which matches my experience, is that LUTs are a bad idea for this footage: it's the LUTs that create all sorts of issues (including banding). That's why I use these curves instead.

[video]http://www.similaar.com/foto/a7s/lut.html[/video]
 
He seems to be just discovering what many people on this forum have known for a couple years now.

Using curves will generally give you a cleaner look than LUTs but...

Not all LUTs are equal in their levels of degradation. I tried dozens of them until I found one that works for me. It's a compromise. I'll accept having to clean up a certain level of color noise and dealing with some banding in exchange for filmic colors and skin tones.
 
Here's an example of one of the most destructive LUTs I have--a film print emulation. I have 8-bit 4:2:0 footage and as soon as I put it on the effect chain there appear splotches of color noise that I remove with noise reduction. It's always right on the edge of banding the skies and walls if I add too much contrast too. It barely works but I think it's ok.

I like the Fall colors I get. The regular Sony colors are so bright it looks like Springtime--especially the bright greens.

Not that it matters, but the plot is: "Trevor looks for Mr. Hauser's grave with a portable shovel and a pint of vodka in his backpack." Maybe I'll add some voiceover narration to help explain it more later.

Full screen: https://www.youtube.com/watch?v=LN5w4X518Hg


 
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I watched the first version you posted, and I do like the colors. If I had to apply something like this, I would try to do it with MB Looks, which doesn't have the IQ problems of a LUT and allows lots of tweaking. It does require good skills, though (and I'm not quite there yet, I usually just apply a preset, tweak it in simple ways, and dial it down).
 
Could you watch version 2 and tell me which version you prefer? 1 or 2?

I have MB Looks and I'll give it a try but I'm not sure I have the skills to get these types of colors.
 
The old still-photography Photoshop trick works on video, too...if you use a LUT with a film look (like FilmConvert), even if you don't want grain, use grain and dial the grain down from the default to between 1 and 5 (I think it defaults to either 50 or 100). The grain will hide any banding issues, and after re-encoding, you'll probably not even see that level of grain.
 
I watched the second version too, and I also liked it. Both would be fine. If you're looking for a "fall" look, I'd go with the second one because it's less orange (the first one says "burning hot" some shots, at least to me). But I really, really shouldn't be telling people what to do with their color grades. Not here. Not yet.
 
I can't stand curves. Looking at old S-log 2 footage from the a7s for awhile because a lot of the footage looked awful. But if I just do a basic, naturalistic grade the footage looks excellent. All I do generally is up the contrast so the blacks hit black and the whites hit white, and adjust the midtones accordingly. Then add some saturation to the midtones and maybe add some warmth and bam, I'm done.
 
Thanks for checking it out.

Yeah, I like the colors in the 2nd one too. Also, it's a less destructive LUT.

I solved the harsh, bright highlights problem by reducing the contrast and lowering the shadows and highlights separately. Much better now.

I think the editing might be a little slow but I'm going to leave it for now. I'm going to wait until I get 10-15 minutes of scenes strung together and see how it flows before I make any changes.

One phenomenon I've noticed a couple times when editing my footage: I work alone at my desktop, I trim and tweak it, then play it back on my big screen tv, to where I think the pace, the overall look is really good, etc.. Then I go to my friends restaurant, plug my USB drive into the back of his 60" flat screen tv and start playing the footage back in front of people and whoa.... It's too fast, too slow, not enough this, too much of that. It's amazing what the presence of other people in the room does for me. I see and feel things I didn't before when I was screening it alone.
 
For me, it's the passage of time that makes me think "too slow, and too long" whenever I see something I posted a couple of months ago. I try to get around this my always thinking "cut away as much as you can" and by having other people check it out when it's almost finished. Sometimes I also let things cool off for a weekend or even a full week, before looking at them again with fresh eyes, but even with those pieces I now feel the end result is too slow XD
 
I was over at my relatives house for Thanksgiving dinner last night and I showed them some scenes that I shot on their big screen tv. My brother-in-law, who's no dummy, heard me saying how the footage was lacking 10 bit this and that and he was like:

"Really? How can it look better than this? What can you possibly do to make it look better than this?"

I mumbled something about 10 bit grading, etc.. He just rolled his eyes.

It reminded me how "regular" people don't pixel peep at all. I think if the dynamic range is good and the color is ok, they're fine with it. Oh, and the sound better be good too or that ruins everything.

Little things that drive me crazy they don't even notice.
 
I completely share that experience. We seem to care about stuff the general public doesn't even see. I still have to try and get the best possible image *for myself*, but at least I've learnt -to some extent- to go "good enough" and move on when stuck trying to fix something that my audience won't care about.

That includes a strong decision not to use external recorders anymore. I used it once, found it terribly buggy and slow and prone to failure, and will stick to internal codecs from now on, even if that means sticking to 8-bit 4:2:0 XAVC-S when the camera could do better on the HDMI port.
 
enjoyable thread.

thank you.

especially because i'm thinking seriously about picking up either the a6000 or rx10ii and both employ the same avc-s 420/8 bit codec that you have referenced.

i look forward to any additional thoughts.

be well.

rob
 
Tough choice. The RX10 II will give you a lot more DR (about a stop or so) but you'll be stuck with deep DoF all the time.
Just for reference, my main camera for video right now is an RX100 IV, and I just bought an a6000 for stills (at $400, I'm just thankful it made me stop lusting about a $7500 a7R II kit).
 
Consumers are use to seeing 8-bpc 4:2:0 video everywhere. Name a place that consumers can see something higher fidelity?

Video games. (still 8 bit)
the photos on the web? (still 8 bit)

We have a mentality in the video game business: I can spend as much time on a road sign, and make it the best roadsign ever built, spend 2 weeks on it, but would have it been better value for the customer if I had spent 2 weeks making the game not suck?

Focus on what your customer cares about, Story, performance, content. You're easily able to hit the minimum quality bar with these s35 cameras.
 
This is true, and I agree...however, since video coming into the home is so degraded by the time it gets there, I'd think starting with a great picture is probably best. If 8-bit 4:2:0 was the original format, and then compressed, uploaded, broadcast or downloaded, and then viewed, would it still look okay? Not rhetorical, just thinking out loud. On my 60-inch at home, most bluray disks and AppleTV iTunes content look good enough, though I occasionally see banding. That's probably the 8-bit limitation of the monitor/TV...but what if it started out 8-bit?
 
It does degrade, but it does so as well if you shoot 10-bit ProRes. YouTube and Vimeo codecs are good, but bitrates are very low and all kinds of issues appear. In the video I linked on the first post, I hear the guy saying "there's no banding here" and I definitely see banding, so it's a YT thing... and it happens on both sources. Still, do this same thing with a codec from a few years ago and you'll see all sorts of other problems, like macroblocking on the skin (I'm looking at you, 5D2/T2i with CineStyle), that you're not seeing anymore with codecs with XAVC-S (no idea about Canon's current DSLR codecs, I abandoned that ship long ago).
 
So, you're saying XAVC isn't the culprit, it's the YouTube/Vimeo compression? That makes sense. Any idea how that would compare with footage destined for a screen who's footage won't originate online? I guess, essentially first-generation out of the workflow (i.e. Compressor). My big question...is the XAVC 4:2:0 going to look good compared to, say, ProRes 4:2:2 coming out of the editing suite (assuming no or light grading)?

I'm about to start shooting a doc and I'm trying to decide if I want the hassle of an external recorder for ProRes 422, or whether XAVC 422 will suffice. I think I'm getting caught up in the minutiae, but I'd rather answer the question now instead of rethinking it after I have hours of footage.
 
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