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bob glusic
any way to reduce noise in build 16
on Jul 18, 2008 at 5:02:18 am

I just returned from filming Glacier park and noticed all my sunrise shots have excessive noise both in the shadows and the red mountains. I was using build 16 and tried Red Alert and Red Cine with the same result. I usually downconvert from 4K to HD and save the movie as 10 bit 422 uncompressed. ASA was about 400. Would appreciate any ideas to save the beautiful shots.

Thanks,
Bob



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David Battistella
Re: any way to reduce noise in build 16
on Jul 18, 2008 at 5:54:26 am



Bob,

Any way to post a still shot of what the noise looks like. Are you processing the shots in REDSPACE when using RED alert?

I have found that with B16 footage and REDSPACE if you increase the ISO then you will find that it now crushes the blacks (thus eliminating noise) which is what most camera's do with gain situations. Also the RED footage does benefit from some post sharpening and a good Color Correction pass as well.

David



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bob glusic
Re: any way to reduce noise in build 16
on Jul 18, 2008 at 3:13:48 pm

Hi David,

I'm not sure how to post a still but would be happy to e-mail it to you directly. I used rec709 as redspace seems to blow out the sky color. Do you know any noise reduction software--I use AF to sharpen a bit and finalize the shot.

Thanks,
Bob



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David Battistella
Re: any way to reduce noise in build 16
on Jul 18, 2008 at 7:15:18 pm

[bob glusic] "Do you know any noise reduction software"

I'd have to see the shot. There are things you can do to reduce noise and it mught have to be done at a channel level. You can, for example identify that the noise is in the blue channel and work on only the BLUE Channel noise.

David





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Ramona Howard
Re: any way to reduce noise in build 16
on Jul 18, 2008 at 3:30:26 pm

David,

Also the RED footage does benefit from some post sharpening and a good Color Correction pass as well.

Is this being applied at the RAW file level or at one of the processing apps.

And if at the processing level, can these be turned off?

Not all want their images mucked with, without that control themself.

Cheers,
Ramona



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David Battistella
Re: any way to reduce noise in build 16
on Jul 18, 2008 at 7:19:31 pm

[Ramona Howard] "Is this being applied at the RAW file level or at one of the processing apps.

And if at the processing level, can these be turned off?

Not all want their images mucked with, without that control themself.

Cheers,
Ramona"


Ramona,

Usually the sharpening and CC would be done on What ever file you have already extracted (DPX, tiff, or QT). RED software offers some of these tools (for those going directly to a file and never conforming, but this can be turned off in those apps.

The RED does NO SHARPENING in camera. This means for a slightly softer image BUT you get to add the amount of sharpening you need "to tasts".. You are not bound by what ever sharpening done at the camera level (which other camera companies do).

I think in this regard RED offers the most flexibility of image control to the end user.

David



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Ramona Howard
Re: any way to reduce noise in build 16
on Jul 18, 2008 at 9:09:31 pm

Thanks David,

I would be careful in saying that all other cameras do sharpening. I do believe this may be inaccurate. So is it safe to assume that the Red camera does no color passes or filtering of any kind to the RAW file.

Cheers,
Ramona



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bob glusic
Re: any way to reduce noise in build 16
on Jul 18, 2008 at 9:31:06 pm

Hi David,

I sent a 4k tiff to Red and they will get back to me. I like your idea of the channels. Are you saying by toning the blue channel down is that the blue slider in RedAlert your talking about or using curves in AF and selecting the blue channel?
Are there any other noise reducing programs for video?

Thanks,
Bob






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Uli Plank
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 7:12:58 am

There's a good noise reducer from http://www.revisionfx.com and one from http://www.chv-plugins.com ( under the repair collection).
Grame Nattress has a good one for Apple's Color, with the advantage of applying it to the blue channel only if needed.

Regards,

Uli

Director of the Institute of Media Research (IMF) at Braunschweig University of Arts


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David Battistella
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 11:14:57 am

[Ramona Howard] "Thanks David,

I would be careful in saying that all other cameras do sharpening."


OK.

Some, but not every single, camera manufacturers add some form of sharpening to their image at the camera level. The RED does not.

Is that sorta-alright-safe-and-better enough?

David



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Mike Schrengohst
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 1:00:47 pm

I have been exporting 16 bit .tiff sequences from RedAlert using RedLog.
I take these into After Effects and add a little noise reduction, a CC pass and export
as Uncompressed 10 bit QT with good results.

Mike Schrengohst
http://www.MotionZoneHD.com


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Ramona Howard
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 2:42:02 pm

David,

By saying all from the start, bad information is being spread, something I nor many others need. We all just want the facts.

Thank you for your information on the camera, sorta :)

Cheers,
Ramona



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David Battistella
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 4:11:41 pm

[Ramona Howard] "Thank you for your information on the camera, sorta :) "


No problem.

Peace.

David




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gary adcock
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 2:48:27 pm

[David Battistella] "Some, but not every single, camera manufacturers add some form of sharpening to their image at the camera level. The RED does not. "

Sorry David

I am with Ramona on this, while that statement may be true for HDV and lesser HD cameras, at the level RED is "at" virtually none of the cameras contain sharpening as a default in the setups and No camera I know of that shoots in any type of RAW imagery does any sharpening what so ever to the image without a good deal of hassle.

I am referring to RED, Genesis, Viper, D21, SII, Phantom, f23 and others do not do any sharpening to the image prior to recording unless the user chooses it.




gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD




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David Battistella
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 7:04:23 pm

[Ramona Howard] "Is this being applied at the RAW file level or at one of the processing apps. "

Ramona,

I have it on very good authority that the only thing applied to the RAW file is compression. That's it.

David



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David Battistella
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 4:19:28 pm

[gary adcock] "I am referring to RED, Genesis, Viper, D21, SII, Phantom, f23 and others do not do any sharpening to the image prior to recording unless the user chooses it."

Gary.

I hear you. Appreciated.

"All" was the incorrect word to use, but I would imagine that "most" of the camera's you mentioned would not have been used in a remote wildlife shoot in Glacier National Park.

Apologies to you and Ramona for not being as detailed as I should have been.

David





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gary adcock
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 5:35:38 pm

[David Battistella] "Apologies to you and Ramona"

good thing is she is not as near as harsh as "Black Burst Bob"

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD




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bob glusic
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 5:48:21 pm

Thanks for the noise reduction software and the tiff sequence suggestion--I'll try it.

Bob





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Ramona Howard
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 6:23:14 pm

I have my moments :)

Red is being used in MANY shoots and we all just need to keep the statements to factual, I know not an easy thing to do when your passionate.

Had I not know your "all" statement to be false, I would have not questioned your leadership role here on the Cow.

I think that is where Bob and I agree, he is just a bit more forthcoming about it.

Cheers,
Ramona



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David Battistella
Re: any way to reduce noise in build 16
on Jul 19, 2008 at 7:06:41 pm

[Ramona Howard] "Had I not know your "all" statement to be false, I would have not questioned your leadership role here on the Cow. "

Ramona,

Just for the record is this the statement you were questioning from my previous post?

"You are not bound by what ever sharpening done at the camera level (which other camera companies do)."

I could see how it suggests "all" in the context Gary was referring to. I was actually just missing the word "some" if this is the case.

Thanks,

David





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Ramona Howard
Re: any way to reduce noise in build 16
on Jul 20, 2008 at 1:09:28 am

David,

That is one of the problem with forums and such, so much is left to interpretation in the way things are worded, it is so important to be precise.

Hey, thanks for the info. Do you know of anywhere that this is documented from Red so we can be 100% sure on this.

Cheers,
Ramona



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Uli Plank
Re: any way to reduce noise in build 16
on Jul 20, 2008 at 6:09:29 am

Graeme Nattress, who is one of the leading developers for Red's codec, has stated it several times on the Reduser forum, and I consider him a honest person.
For me, the Red (in particular with firmware 16) is a camera with very low noise. What you are seeing might be footage without any grading. The Red One (like any other camera shooting raw) has a wider range of contrast than an ordinary screen can show properly. So, the image needs to be tweaked in post to give you that 'cinematic' look many of us are after, and part of the process is crushing the blacks to some degree in most cases.
Plus if you render the clips in 4K at best de-bayering (I know that takes a lot of time) and scale them down to 2K with a good scaling algorithm, there is quite some noise getting lost.

Hope this helps,

Uli

Director of the Institute of Media Research (IMF) at Braunschweig University of Arts


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David Battistella
Re: any way to reduce noise in build 16
on Jul 20, 2008 at 5:12:17 pm

[Ramona Howard] "Do you know of anywhere that this is documented from Red so we can be 100% sure on this."


This might be something we find out when they release their SDK (in the coming weeks)

That is my best guess. I think that RED is pretty transparent about the amount of compression in r3d.

David



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Graeme Nattress
Re: any way to reduce noise in build 16
on Jul 20, 2008 at 5:58:01 pm

There is no sharpening on the RAW R3D recording in camera. All that is done is that the raw data is sent to the REDCODE compression and sent to the drive or CF. In post, the tools do allow a small amount of basic sharpening to be added if desired, or turned completely off, if desired.

It's also very difficult to do any sharpening on Bayer pattern raw data. I don't think I know of any camera, be it movie or stills, that uses a Bayer pattern sensor, that does any sharpening on the RAW data.

Most video cameras do incorporate some form of sharpening, but with some high end cameras, I don't believe there's public documentation either way on exactly what image processing is applied in camera.

Another aspect to sharpening, is aliasing artifacts from lack of optical low pass filter, inadequate optical low pass filtering or inadequate electronic filtering in downconversions. Each of these can lead to images looking sharper, but also, obviously the unwanted artifacts of aliasing.

Graeme

- http://www.nattress.com - Film Effects and Standards Conversion for FCP


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Simon Blackledge
Re: any way to reduce noise in build 16
on Jul 20, 2008 at 1:12:06 pm

Few thoughts...

Take a tiff 16 bit into photoshop. Check each channel.. which has the most noise?

Probably blue most though it's better in 16.

My favorite way to denoise is either http://www.neatvideo.com/

or if an image seq I run a batch on the final seq using neatimage in PS.

S





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bob glusic
Re: any way to reduce noise in build 16
on Jul 20, 2008 at 4:19:11 pm

Thankyou for the suggestions--I will look into Neat Video. I just tried DE-Noise and it worked very well. Red support wanted to work on the Raw file so I mailed it out Thursday and will wait to get there input. I tried processing a tiff sequence and lowering the blue channel in which both helped a little but more noise reduction was needed.

Bob




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David Battistella
Re: any way to reduce noise in build 16
on Jul 20, 2008 at 9:49:12 pm

Bob,

If you would like to upload a shot e-mail me (click on my head in the banner) and my e-mail is in the bio.

I'd be glad to have a look and see how I might be able to help you out.

Cheers,

David


BTW: You site is really nice. What do you capture image with besides the RED.



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bob glusic
Re: any way to reduce noise in build 16
on Jul 21, 2008 at 1:49:30 am

Thanks David,

I'll send you the still when I return from my filming trip later this week.

Thanks,
Bob



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Uli Plank
Re: any way to reduce noise in build 16
on Jul 22, 2008 at 5:35:39 am

It's not about lowering the blue channel, it just should befiltered against noise independent of the other channels.

Regards,

Uli

Director of the Institute of Media Research (IMF) at Braunschweig University of Arts


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Don Starnes
Re: any way to reduce noise in build 16
on Jul 23, 2008 at 5:19:39 pm

I get the sense that RED's image gets noiser when boosting the blue channel to color correct for red (or orange) light. Isn't the sensor optimized for 5000ish K light (I beleive that I heard this somewhere)?

Wouldn't it be best to photograph with the RED using 5000ish K key light or with blueish color correction filtration on the lense? I'd particulary like Graeme's opinion on this.

Don

Don Starnes
Director of Photography
http://www.donstarnes.com


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Uli Plank
Re: any way to reduce noise in build 16
on Jul 23, 2008 at 7:51:59 pm

How should weakening the red channel help the blue?
Color correction can always be done in post, but like all electronic sensors the Red is relatively insensitive to blue. So, if the incoming light is lacking blue (sunset/sunrise, tungsten) the blue channel will be even noisier than it is under normal daylight. You can't help it with filters, since filters can only take light away, but don't add any energy to remaning colors.

Regards,

Uli

Director of the Institute of Media Research (IMF) at Braunschweig University of Arts


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Don Starnes
Re: any way to reduce noise in build 16
on Jul 23, 2008 at 9:41:42 pm

Uli:
So, if the incoming light is lacking blue (sunset/sunrise, tungsten) the blue channel will be even noisier than it is under normal daylight.

Exactly; shooting in normal daylight is less noisy than shooting in tungsten. So: how about only shooting with the RED in normal daylight? Or, in tungsten key light by making a close approximation of daylight by using, say, an 80C filter to get the color temperature close to 5000K?

Don

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Don Starnes
Director of Photography
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David Battistella
Re: any way to reduce noise in build 16
on Jul 23, 2008 at 10:40:13 pm


One thing that is being overlooked here is that the Kelvin can be set AFTER the fact because with RED you are recording a RAW file.

The Color temperature is METADATA ONLY.

IE; I have solved many noise problems by setting a one light in the REDCINE exporting and then rebalancing the shot on a second CC pass.

I rarely set the white balance to 3200K and I find that bumping the Kelvin to about 4300K warms up the QT reference file, reduces noise and is easily corrected back if need be.

It is true that the sensor performs best at about 5000K and is optimum, but just take a moment to think of the RED as BW film in terms of getting your exposure and latitude correct and then you have AMPLE room to tweak the Kelvin and extract the best image.

I try to think about it in these terms:
The noise is happening based on l how you are instructing the RAW file to debayer more that it does in the sensor itself. To me it is more about light intensity than it is about color temperature. If you hit the sensor with a lot of light then you can make just about any image look really good.

I forgot to ask bob if where his Kelvin was set to but if it was 3200K and he bumped it to 4300K a good chunk of the blue channel noise would be gone.

David



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Don Starnes
Re: any way to reduce noise in build 16
on Jul 23, 2008 at 11:49:20 pm

David:
It is true that the sensor performs best at about 5000K and is optimum, but just take a moment to think of the RED as BW film in terms of getting your exposure and latitude correct and then you have AMPLE room to tweak the Kelvin and extract the best image.

And this tweaking of a warm image (which probably means increasing the "gain" in the blue channel and decreasing the red channel) seems to increase the noise in the blue channel. And so why not shoot in 5000ish K light?

If you hit the sensor with a lot of light then you can make just about any image look really good.

Probably so.

Don Starnes
Director of Photography
http://www.donstarnes.com


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David Battistella
Re: any way to reduce noise in build 16
on Jul 24, 2008 at 4:28:41 am

[Don Starnes] "And this tweaking of a warm image (which probably means increasing the "gain" in the blue channel and decreasing the red channel) seems to increase the noise in the blue channel. And so why not shoot in 5000ish K light?"

This matters only to the METADATA you are laying in to the QuickTime Proxie file.

This is what I am getting at. Following VIDEO camera rules with RED does not always apply. You have to think outside the box a bit. If you think that exposing it with 5000K light is better then by all means do it.

I would for sure light and balance a green screen this way. More to the point, it's just nice to have this much flexibility with an image.

David


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Graeme Nattress
Re: any way to reduce noise in build 16
on Jul 25, 2008 at 3:56:29 pm

Let me add that all silicon based sensors are insensitive to blue light, and most sensitive to red light. Nothing much we can do about that other than alter the laws of physics :-)

That means all sensors are, if you remove the colour processing and gains, "balanced" more towards daylight.

The only ways you can alter this are with gain on blue (which will reduce blue dynamic range, and trade digital noise for analogue noise) or filter red and green, reducing the light hitting them, which just makes them, all other things being equal, noisier.

Graeme

- http://www.nattress.com - Film Effects and Standards Conversion for FCP


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Uli Plank
Re: any way to reduce noise in build 16
on Jul 26, 2008 at 6:56:59 am

The only situation where you might want to filter out some red is a high contrast scene, where you could get your sensor saturated much earlier on red than blue or green, so you can expose a bit higher and stay away from the noise floor.
But in most situations you can allow one or even two channels to clip, since the DRX in the Red software will copy information from the unclipped channels into the saturated ones, getting back some detail. Of course this will make you highlights loose color, but there isn't much color in highlights anyway and we have used this trick in post for a quite some time. Video cameras do pretty much the same when you play with knee and matrizes.

Regards,

Uli



Director of the Institute of Media Research (IMF) at Braunschweig University of Arts


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Graeme Nattress
Re: any way to reduce noise in build 16
on Jul 26, 2008 at 1:41:32 pm

Or if you can, rather than filter the camera, filter the light, but keep it bright. These advice should help for any silicon sensor based camera, actually.

DRX tries to keep colours as best as it can, but at some point, indeed, it is guessing. However, I've compared results from raw converters that don't have such a feature, and I much prefer having DRX available.

Graeme

- http://www.nattress.com - Film Effects and Standards Conversion for FCP


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Uli Plank
Re: any way to reduce noise in build 16
on Jul 26, 2008 at 4:22:37 pm

Well, Graeme, filtering the light might be difficult regarding the initial question ;-)

But I agree, DRX is doing a great job which needed quite some fumbling when we still did that in other programs. While we are at it, may I ask what precisely is the meaning of the values in DRX? F-Stops ?

TIA,

Uli

Director of the Institute of Media Research (IMF) at Braunschweig University of Arts


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Graeme Nattress
Re: any way to reduce noise in build 16
on Jul 26, 2008 at 4:28:40 pm

DRX always tried to scrape back as much dynamic range as it can. The value refers to the percentage amount of the effect used.

Graeme

- http://www.nattress.com - Film Effects and Standards Conversion for FCP


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