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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

ProRes 422HQ why does it have Banding?

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BigLu

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Can someone break down in detail ProRes 422 and ProRes 422HQ
and 8Bit and 10Bit Uncompressed codecs.

even with minimal color grading ProRes 422HQ has some awful banding in the skies and on white walls, we also see it in the skin tones at times.

What is up with the banding anybody?
 
Just to make sure, you're positive that it's not the display doing this?
 
YUV & 4:2:2 used by ProRes are the likely cause.

ProRes is an excellent codec, but it's got some weaknesses, and you've found the main one...

Contiguous pixels of _nearly_ the same value are the achilles heel of most codecs. Smooth gradients, fog/smoke, etc... will show a codec's warts pretty quickly.

You could try Cineform, which includes 4:4:4 color sampling. It's the best codec I've ever used, I recommend it highly. Or, for the sections that are giving you trouble render out to a 10-bit RGB file sequence like DPX or Cineon.

If you're rendering out of RedAlert/Cine or AE / Premiere you're ok. If you're rendering from FCP you may run into the 2k/YUV limitation where it's not possible to remain in RGB colorspace without workarounds (don't have the details handy - reduser posts elsewhere do outline the process if I remember correctly).

cheers,

JT
 
I get heavy banding in prores when exporting from RedCine (which effectively renders the codec unusable in the RC environment in many circumstances), but NOT when exporting from FCP... (having used the QT proxies as source) weird!
 
ProResHQ is a 10bit 422 codec but it is highly compressed hence the banding. I get banding in the skies of uncompressed 10bit files as well though not as bad. You will see the majority of the banding disapear in 10bit DPX 444 files. However, running 1080p DPX comes with a price as does everything high quality.
 
I have seen this as well in RedCine outputs. There are some threads in the RedCine section but as far as I know nobody from RED or Assimilate cared to answer while I think it is a pretty big limitation. In general I would say don't use RedCine for any quicktime output.

Do a test and see if Redrushes or RedAlert are better.
 
One thing worth mentioning is that when you push the gamma curve in the area that had lots of gradation then that will result in getting the banding in ProRes. I kinda stop using the curve as much as possible, then use brightness, shadow and exposure to keep the curve close to flat.

I'm not sure if this is technically right though.
 
Re. RedCine - I would wager that the banding you are seening from RedCine output has more to do with the power of the color tools in RedCine than with anything the software is doing different than FCP.

Since I don't use RedCine I can't say if there's a prores issue, but I can say that I've seen banding in ProRes from many different softwares in many different circumstances.

Kaku - the ideal solution is to use a more appropriate codec, but short of that, it is best to not 'stretch' areas of similar pixels (gradients, fog/smoke, sky) very much, which is what curves allow the user to do. Simple lift/gamma/gain moves that you describe are less likely to separate the gradient values as much, but it is still possible to induce banding.


regards,

John T.
 
BigLu said:
Can someone break down in detail ProRes 422 and ProRes 422HQ
and 8Bit and 10Bit Uncompressed codecs.

even with minimal color grading ProRes 422HQ has some awful banding in the skies and on white walls, we also see it in the skin tones at times.

What is up with the banding anybody?
Click to expand...

All usual and should be avoided for grading, IMO.

Judging by your work (very nice work, btw) I think you won't find 10bit Uncompressed satisfactory too.
For light work 10bit Uncompressed can be okay. For heavy stuff = no go.
 
Tool Color, viewing with an SGI FW 9011 i believe equal to Sony FW900 and an Apple Cinema Display 30inch monitor.
 
Use the 1k or 2k quick time proxies to edit and grade, shoot REC 709 for best grading results from Proxies , grade away.. no banding. clean as clean as can be.
Rendered out Pro res files Band up due to compression. No saving it.

When happy with grade and edit, Render out pro res then.

see results
http://www.zoomfilmtv.com.au/tvcs/toia/html/griffith_global_a.html

done

easy.
 
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