Posterizing

[Steve Sherrick]

I noticed that I had a lot of posterizing today while shooting, and it was noticeable on both RED LCD and playback on an HD TV from the HDMI output. I'll be able to troubleshoot tomorrow when I get it into REDCINE, but is it possible that I had something set wrong? This wasn't a false color type of posterizing. Everything looks normal for the most part but things that are out of focus seemed to have this issue even more. For example, if I had a white pole, rather than a nice solid white pole, it looks like someone applied the posterize effect to it. My thought are:

1. Maybe this is a dithering issue going from 4K to 720.
2. Certain things are triggering it, as in certain lighting situations
3. Could it be that I have something set in my settings that could be causing this to appear on preview?

Once I get it into REDCINE I can see if it is still there. If it is, and it's in the footage, then I'm really lost as to what is causing this. I haven't noticed it before. The only two variable I have changed is I updated to Build 15 release version and I added the Nikon Mount with a set of Nikon primes.

Thoughts anyone?

[donatello b]

did you do the black shading after the update?
if yes .. was lens cap on the whole time etc

[Kenn Michael]

Aren't the video taps 8 bit? That would be a cause for posterization of smooth gradient material.

[Steve Sherrick]

I did do a black shading and I always do it with aperture closed down, lens cap on, black wrap over lens, in a dark room because I'm paranoid about this.

Maybe it is the 8bit tap. But I'm noticing this in my Nikon test I posted in the footage section. I had edited that from 2K proxies and rendered in a Pro Res HQ with Hi-Res selected in settings. Hmm.....

I'll have to investigate tomorrow.

[JANDY]

This posterization is always present on the LCD monitor. It is simply more noticeable in certain conditions. I assume it was present in the 'director's monitor' because of the HDMI output. I've always used and SDI output and never had this happen.

[Steve Sherrick]

Yeah, it's just the truncation from 12 to 8 bits. The LCD shows this truncation pretty severely at times. But it doesn't affect things once you know why it's happening and that the RAW footage doesn't have it.

[Stuart English]

The Preview HD-SDI and HDMI outputs are both 4:2:2 at 10 bits. So you shouldn't see anything like that there..

[Ramesh Jai]

The Preview HD-SDI and HDMI outputs are both 4:2:2 at 10 bits. So you shouldn't see anything like that there..

Can I safely deduce that if I see the posterizing effect on the LCD monitor I will not see it in the RAW footage?

[Graeme Nattress]

I've never seen posterization in the RED raw footage - ever.

Graeme

[Ramesh Jai]

I've never seen posterization in the RED raw footage - ever.

Graeme

So if I may ask, what is causing the posterization in the LCD monitor? I'm still on build 15.