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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 :)

Surprising Amount of Noise

I

IanK

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I am conforming my first Red project. I tried Redcine but was disappointed with some of the workflow. I worked in Redalert and was very alarmed with the noise in level in the image. Please let me know if you can help me. We shot this on a stage and it was well exposed. I posted the footage (in half size Pro-Res. Even the 10bit uncompressed has noise)


http://www.territimely.com/Noise/


Thanks
 
Ian - did you do a full-res decode? Or just half or quarter res? Those are considerably more noisy.

Full res decodes to full 4K and then scales down to 1080p or whatever you're going to. Because you're averaging pixels it is less noisy.

Also, Red outputs from quicktime, Red Alert, etc don't crush the black floor by default so you end up looking at a kinda awful pasty dark gray noise. If you crush the blacks this goes away.

That said, Red can be reasonably noisy compared to a film telecine where they have sometimes pretty sophisticated noise reduction boxes helping out. So consider running software noise reduction on your footage.

I just directed a short film where we shot at between 640 and 1000 ASA for pretty much everything. So far so good. I'm probably going to run NR on the footage and then add some film grain back in. But then narrative stuff doesn't need a noise free print - most of my favorite films are grainy as hell ;)

Bruce Allen
www.boacinema.com
 
I didnt change the white in post and I did full-debayer quality. I will try crushing the blacks a bit. THank you.


Ian
 
Bruce, do you know of any good noise reduction software?



Ian
 
Does having the debayer detail at the maximum give you more noise or less?
 
IanK said:
Bruce, do you know of any good noise reduction software?

Ian
Click to expand...

Personally I have used the the stock After Effects Remove Grain filter on EVERY Red project I've done - I always hit at least one shot when I think "gee I wish I had less grain". Lower than default settings (they are too strong), temporal noise reduction turned on (this makes it much smarter as it looks to the frames before & after it for info - but also much slower...).

Others? The Foundry's Furnace plugin has an excellent degrain filter. Re:Vision software has a degrainer I want to check out. Also I should probably try GenArts Sapphire... they probably have something good in there.

Anyone else have recommendations?

Also, try setting ISO to 320? Depending on the project you could also try some ProMist style effects?

I am rather surprised people don't talk about this more. Maybe they are in denial? But I think denoising for Red footage is as necessary as Magic Bullet or some kind of de-blocking process is for DV/HDV, or film grain removal is for scans.

Remember, you can always add some nice film grain afterwards if you want. Much nicer than Red grain IMHO. Or print to film. But that's expensive...

Bruce Allen
www.boacinema.com
 
Thanks Bruce. Just wondering if you had an answer to my previous question about the debayer detail level. Had mine set at 'Leading Lady" as I thought that would be softer for noise. Is that incorrect?


Thanksa again
 
Nattress plugins also has a denoise and priced right too!!
 
Debayer detail level---Higher detail gives you more or less noise?
 
phaz said:
Nattress plugins also has a denoise and priced right too!!
Click to expand...

Yeah, agree - PC / After Effects / OpenFX version please, Graeme! FCP & Color suck as noise reduction plugin hosts (sometimes you want to do the NR before you down-res - with FCP & Color you are out of luck since they can't handle 4K).

Anyway, phaz, you getting good results? I'd love to see some before and afters of the Nattress plugins. I promise to post my before and afters when I am further into the current short film.

IanK said:
Debayer detail level---Higher detail gives you more or less noise?
Click to expand...

It hasn't made much of a difference for me. Also, noise is not just more or less - it's about the character / grain of the noise.

I personally go for higher detail. It perhaps gives more noise, but more detail also. So you maybe can do more aggressive noise reduction later and feel less of a sharpness hit?

Also, I'd guess that Red might prioritize finessing their higher-detail algorithms over their lower-detail ones? No real reason for this guess, except that presumably when they want to show off the detail of their camera by wowing people with zooms into 4K material at tradeshows and whatnot, they would probably not pick the softest option. So they'd want to make sure the higher detail options worked well?

Anyway, what do you guys think about the NR option (in RedCine, don't know if it's in the others)? It seems cool but does weird things to the reds (makes high detail stuff with very bright reds a lot darker) and I'm not sure whether it's good or bad?

Bruce Allen
www.boacinema.com
 
The noise reduction is only visible in full resolution.
 
Bruce Allen said:
Also, Red outputs from quicktime, Red Alert, etc don't crush the black floor by default so you end up looking at a kinda awful pasty dark gray noise. If you crush the blacks this goes away.
Click to expand...

Can you explain what you mean by 'crush the blacks'.

We've got a noise problem on some footage which ultimately is being compressed to FLV for the web. Anything we can do to reduce noise/grain is a big bonus for us both in terms of image quality and file-size.

Thanks
 
Apply directly to the full data set

Apply directly to the full data set

I have found that applying the right adjustments to a full res full quality debayer of the 4K 12-bit RAW image in Scratch prior to down-sampling results in less visually appreciable noise. IMHO if you are going theatrical, have a picky client or just a lot of important things like skin tones in zones 2 & 3 it makes a significant difference. YMMV.

It is my assumption that the matrix & process settings in Scratch actually affect the application of the algorithm. Graeme? Luki?
 
I've posted this in a few other places as well...I am also seeng lots of noise in the shadows and I'm shooting at ISO 200-320. ...and I can only crush the blacks so much. A friend of mine says his red is so much cleaner looking than mine. In fact my canon a1 looks cleaner in the blacks than does my red. I'm begnning to think I have something wrong.

Jeremiah
 
IanK said:
Bruce, do you know of any good noise reduction software? Ian
Click to expand...

Ian earlier in this thread Bruce said;

Bruce Allen said:
That said, Red can be reasonably noisy compared to a film telecine where they have sometimes pretty sophisticated noise reduction boxes helping out. So consider running software noise reduction on your footage.
Click to expand...

Well the most widely used device in the Telecine world is the Digital Vision DVNR - and this product is now available as DVO in all of our software products - it does clean up the noise (most noticable in the Blue Channel) very well.

Regards

Nigel
 
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