Noise in dark seamless backgrounds

[Mike Berkofsky]

We just shot our first Red project.
As a director/cameraman I've always specialized in cosmetics and fashion.
We found that shooting against a black or a dark background (seamless):help: :help: created rampant noise in the background - but not on the subject. I have tried all the rendering options in Red Alert but the noise is still there. Where are we going wrong?
Mike Berkofsky

 

[David Groundwater]

i'm no great expert... but assuming the camera was properly black balanced, play with the curves and crush the blacks a bit.

also, have a look at the shot under the different gamma profiles in red alert - you'll get very different results - especially with the export settings.

if you shot under tungsten, it may well be noisy. if that is the case, try setting the white balance back to 5000 rather than 3200 and do your colour correction in another application like after effects or whatever - i've found that produces less noise in the blue channel.

prior to build 16, i personally found the camera to be very noisy but that has been much reduced. the first time i saw the noise in the blue channel under tungsten i just about had a heart attack... it's far better now.

if your still not happy, record a very short bit of black and email the r3d to red support to check that there's nothing wrong with the camera.

best of luck,

david

 

[Irri]

I've noticed this on a couple of shoots. Both B17. It seems different to older builds. Maybe I am imagining it, but it seems really noisy when shooting blacks.

 

[Bruce Allen]

Set to 320ASA and crush the blacks in Redcine - I almost never use the last 5-10% or so. Render out at full quality (4K decode), scaling down to the format you want to edit in. Try Mitchell scaler.

If you're using a FCP / R3D Quicktime proxy workflow it looks milky and awful. But you don't have to transcode - you can get editing right away. That's the tradeoff at the moment, I think.

EDIT: sorry, just saw you were using Red Alert.

Yeah, try just crushing the blacks out. Or doing a noise reduction pass later on.

Bruce Allen
www.boacinema.com

 

[B Stanford]

Noise in shadows

Noise in shadows

Had the same issue on a recent dance shoot where the dancers were lit tungsten with the background audience in shadows. Changing the color temp up closer to native daylight eliminated the noise.

 

[Mike Prevette]

One thing to note the Red intentionally does not apply any crush to the blacks. Almost every other camera on the market applies some amount of internal curve before it spits anything out. Red shows your what is actually being recorded and shows everything down to the noise floor.

It expects you to apply a crush of your own liking. Another thing to note is the gamma and noise reproduction on a computer monitor seems excessive compared to how things end up on a HD monitor.

Also I've noticed The Prores and DVCProHD encoder in RA and RedCine to add a lot of noise. Try a DPX or umcompressed render comparitively it's a lot cleaner.

 

[Mike Berkofsky]

Mike,
Thanks for the info - I did not try DPX.
Mike Berkofsky