Banding Issues

[David Cho]

So is it normal to see banding or strange bullseye like banding patterns on the Red 5.6 inch lcd? Because I am assuming that these lcds are under 16 bit.

I see really bad banding and noise when I preview the full res proxy on quicktime but when I export full resolution tiffs I do not see the banding or much noise at all.

 

[David Mullen ASC]

Keep in mind that the monitor out signal is only 720P and a quickie real-time debayer, I think 1/4 debayer resolution, so it's going to have artifacts. I believe it's an 8-bit RGB signal but I could be wrong, it could be 10-bit.

 

[Alexander Ibrahim]

Yeah, I've been seeing banding on my ProRes HQ Half High files. Is my Imac not a proper video monitor?

I didn't notice an answer so:

No, your iMac- or any computer display for that matter is not a "proper" video monitor.

In order to see your ProRes files properly you need an i/o board and a separate video monitor.

Unfortunately the iMac can't support that, as it has o expansion slots.

A MacBook Pro with a Matrox MXO2 would support you.

Most users prefer a Mac Pro with a Blackmagic or AJA i/o board installed.

Then you should get a professional video monitor with an SDI input.

Failing that, you can use an HDMI video monitor, provided you have a professional I/O board which will allow you to do a reasonable calibration. I wouldn't go this way unless budget was a huge constraint (as it often is for me.)

 

[gbalaji]

I need to see the R3D, and I can't look at it until the weekend at the earliest, so if that's ok, email me graeme @ red . com and arrange to send me the file and I'll investigate for you.

Graeme

Graeme,

Send the download link of R3d footage you asked for. Our film is getting released in another 3 weeks, expecting reply ASAP.

 

[JonathanF]

David,

I wanted to point out to you that all but the most expensive and specialized computer monitors are 8 bits per channel. Your iMac is an inexpensive consumer display and it is not going to perform well.

HP's 24" LP2480zx DreamColor monitor is one low cost (< US$ 2500) monitor that does not suffer this type of issue if it is set up properly and driven by the correct hardware.

Monitors that do not suffer from this problem also require specialized graphics hardware to drive them like the new top end nVidia cards which are now (as of very recently) capable of 10 bits per channel to graphics.

I do not know if the Mac drivers support this, the Linux ones do for sure.

Alternately there are some high end cards that can deliver 10 bit 4:4:4 to high end HD SDI monitors over dual link HD SDI. The DVS cards are one example.

Any time you try to display high bit depth source on a monitor that:

1. Is not calibrated
2. Is not of sufficient bit depth
​

You will see these issues. This is why most editorial houses either have very expensive (many tens of thousands of $$$) HD monitors beside their editing/grading workstations, or invest in projection systems which are equally if not more expensive.

The R3D footage is 12 bits before processing. If you are outputting your footage to ProRes 4:4:4 then you are outputting to a 10 bit Quicktime and then viewing that 10 bit file on an 8 bit display. I would EXPECT banding.

Try ProRes 4:2:2 and see if the resulting 8 bit transcoded quicktime displays better. If not, you are going to need a proper graphics card and a proper monitor.

 

[James T Mather]

I seem to recall David Fichers Film "panic room" (which was all shot at the bottom of the curve) needed to be graded on a specialised system as Dvd hit it hard on the banding issue.

Also from using Photoshop for a few years I can say that banding was often avoided in 8 bit by adding 2 to 3% noise (utterly invisible to the eye) but paradoxically smoothing out transitions. might try this on low-end-of-the-curve footage destined for 8 bit output. (obviously in a video sense though - only 2/3% though)

best. J.