Welcome to our community

Be a part of something great, join today!

Register Log in
  • 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 :)

REDWideGamutRGB and Log3G10

Graeme Nattress

Graeme Nattress

RED Problem Solver
Joined
Dec 28, 2006
Messages
6,496
Reaction score
16
Points
38
Website
www.nattress.com
I want to get this thread going for technical questions on REDWideGamutRGB (RWG) and Log3G10, and how they fit into the new IPP2 system. To start:

https://www.red.com/downloads/585358faf01b3062ab0009f8

is a white paper I put together with the basic math, sample code, graphs and details so you can integrate RWG and Log3G10 into diverse workflows.

Graeme
 
Making a sticky! (feels good, it's been a while!)

Adding this here.

If you are looking to get started with IPP2 today either in REDCINE-X Pro or 3rd party applications, here's how to start.


Phil Holland said:
I'm getting asked a bunch either how or for the IPP2 Preview LUT. Here's a short explanation to get people started.

Download this IPP2 Preview LUT (this is RED's official preview LUT):

http://www.phfx.com/temp/reduser/phfx_RED_RWGRGBwithLG310_IPP2PreviewLUT.zip

Instructions for REDCINE-X PRO:



For 3rd Party Applications, do the same as above and apply the 3D LUT via whatever program you are using.
Click to expand...


This is an ongoing development and there will be additional workflow notes as IPP2 is fully released and new features come via software as well.
 
Last edited:
awesome work!
 
Flies way above my head. But looks great I think. So when can we have this in camera? And will we be able to playback with RWG,LoG3g10 +lut in camera or only see that while in record or livefeed?

Seams like a LOG3G10torec709 combo thing would be what we need in camera and then in grading be able to switch to Log3g10 and choose what lut to go with. or how is it meant to be implemented on the cameras?
 
In camera now with today's firmware release.

Graeme
 
Hey Graeme I have a question about LOG3G10. If you used it as your recording space could you theoretically get more dynamic range out of a camera because of the number of stops LOG3G10 has above mid gray? Right now when you click on tools and see the RAW sensor info I'm assuming that's a traditional LOG image. Or is its primary purpose to be a large holding color space that is used to easily convert an expanded raw color space into different working color spaces?

I've been experimenting with RWG and LOG3G10 a great deal since it was released in Da Vinci Resolve. I can clearly see the benefit of RWG especially in conjunction with a saturation boost from a LAB color based node. I've been getting much better color contrast and speration without colors ever becoming too garish and over saturated. I still have not found, however, the real benefits of using log3g20 vs RED Log Film. To my eye, once you normalize the footage, the dynamic range between Red log film and LOG3G10 looks the same. One just uses more video gain then the other to get there.
 
Quick test this morning with the new IPP2 in camera preset (Epic-W). Without pixel peeping my first feeling was that there are subtle improvements in skin tones which is nice.

But what I don't understand is when I load the files in RedCine the color profile shows me DragonColor2 and Redgamma4.
So, is the IPP2 in camera for preview only?
 
I don't use Redcine X but if you look in the card that you shot the new footage there should be a IPP2.cube lut that you can then bring into a program like Da Vinci Resolve and use it there. My clips came into Da Vinci Resolve as RWG and LOG3G10. One note for me is I used the IPP2 look as a LUT in my Weapon Helium. Don't know if that's necessary to make the camera include the LUT in the clips folder on the card. Shooting with a LUT always included the LUT I used with my footage even before this new build.
 
Thai Christen said:
Quick test this morning with the new IPP2 in camera preset (Epic-W). Without pixel peeping my first feeling was that there are subtle improvements in skin tones which is nice.

But what I don't understand is when I load the files in RedCine the color profile shows me DragonColor2 and Redgamma4.
So, is the IPP2 in camera for preview only?
Click to expand...

You need the "unlisted" beta version of RCX, the download link is in the first post here

Or use the lut Anton mentioned.
 
Anton Esteban said:
Hey Graeme I have a question about LOG3G10. If you used it as your recording space could you theoretically get more dynamic range out of a camera because of the number of stops LOG3G10 has above mid gray? Right now when you click on tools and see the RAW sensor info I'm assuming that's a traditional LOG image. Or is its primary purpose to be a large holding color space that is used to easily convert an expanded raw color space into different working color spaces?

I've been experimenting with RWG and LOG3G10 a great deal since it was released in Da Vinci Resolve. I can clearly see the benefit of RWG especially in conjunction with a saturation boost from a LAB color based node. I've been getting much better color contrast and speration without colors ever becoming too garish and over saturated. I still have not found, however, the real benefits of using log3g20 vs RED Log Film. To my eye, once you normalize the footage, the dynamic range between Red log film and LOG3G10 looks the same. One just uses more video gain then the other to get there.
Click to expand...

Log encodings are just containers. The key feature of such a container is that it's big enough to hold what you want to put in there! REDLogFilm adheres to the Cineon spec, which means it can encode a linear light value up to about 13.5, which gives you a bit over 6 stops above mid grey before it runs out ( log2(13.5/0.18)=> 6.2288 ) So if your float image always has values lower than 13.5, REDLogFilm works fine. Similarly, if you're grading a REDLogFilm image and you don't need to produce or grade float values (as equivalent log code values) greater than 13.5, you're not constrained by the log encoding.

On the camera side, ISO calibration is done by constructing a linear gain such that scene mid grey gets mapped to 0.18 in float. Any element in the scene that is brighter than mid grey will get mapped to higher and higher float values, so as you increase the ISO from 800 to 1600 to 3200 to 6400 you're adding a stop of gain each time and those bright areas of the image are getting brighter and brighter. Depending on camera, sensor and OLPF the max gain you can apply before REDLogFilm runs out as a container space is going to be different, but it's inevitable you'll reach it at some point.

On the grading side of things HDR is increasingly important. SMPTE2048 spec encodes a signal up to 10,000 nits. Say we reasonably put scene mid grey at 18 nits, that means the 10,000 bit peak brightness of the spec is just over 9 stops above mid grey ( log2(10000/18)=> 9.1178 ) and thus if you're trying to grade a log image that represents linear light data, you're going to want it to be able to contain more than 9 stops above mid grey.

Given the above necessary container size, Log3G10 encodes 10 stops above mid grey and thus means increasing ISO won't constrain the dynamic range of the image, and in grading you can push highlights beyond SMPTE2084 spec. But it's no bigger than it needs to be either, and that's good for precision.

So you may not have come up agains the limits of Cineon spec yet, but sooner of later you will, and hence Log3G10 makes sense as a larger container format.

Graeme
 
Thai Christen said:
Quick test this morning with the new IPP2 in camera preset (Epic-W). Without pixel peeping my first feeling was that there are subtle improvements in skin tones which is nice.

But what I don't understand is when I load the files in RedCine the color profile shows me DragonColor2 and Redgamma4.
So, is the IPP2 in camera for preview only?
Click to expand...

IPP2 Preview targets a monitor with REC709 primaries and BT1886 gamma. That is why when you open your R3D in REDCine-X IPP2 Preview, it will set colour space and gamma space to REC709 and BT1886. Similarly The various RedColors and gammas target a monitor with REC709 primaries and BT1886 gamma, and thus when you open in normal REDCine-X, you'll see it coming in as DragonColor2 and Redgamma4. For the IPP2 preview build of REDCine-X (which also expands your set of targets to include other colour space and gamma options) go here: http://www.reduser.net/forum/showthread.php?152780-Holiday-Update-IPP2-Preview-Build


Graeme
 
Graeme Nattress said:
IPP2 Preview targets a monitor with REC709 primaries and BT1886 gamma. That is why when you open your R3D in REDCine-X IPP2 Preview, it will set colour space and gamma space to REC709 and BT1886. Similarly The various RedColors and gammas target a monitor with REC709 primaries and BT1886 gamma, and thus when you open in normal REDCine-X, you'll see it coming in as DragonColor2 and Redgamma4. For the IPP2 preview build of REDCine-X (which also expands your set of targets to include other colour space and gamma options) go here: http://www.reduser.net/forum/showthread.php?152780-Holiday-Update-IPP2-Preview-Build


Graeme
Click to expand...

Gotcha, thanks a lot Graeme!
Playing with some test files now.
 
Just started up the new RCX, is there any new settings to apply or is it just the basic function of the software?
 
Christoffer Glans said:
Just started up the new RCX, is there any new settings to apply or is it just the basic function of the software?
Click to expand...

The IPP2 Preview REDCine-X build is just that - it only does IPP2 preview and if you want to go out to REC709 / BT1886 there's not much else you need to do. It only does IPP2 so there's no need to turn on a switch to access it. You can select from the named standard colour spaces and also gamma specs. As we move towards the full IPP2 implementation we'll separate out the technical and creative controls, and also give you more of a colour managed workflow using the full IPP2 system.

Graeme
 
Graeme Nattress said:
The IPP2 Preview REDCine-X build is just that - it only does IPP2 preview and if you want to go out to REC709 / BT1886 there's not much else you need to do. It only does IPP2 so there's no need to turn on a switch to access it. You can select from the named standard colour spaces and also gamma specs. As we move towards the full IPP2 implementation we'll separate out the technical and creative controls, and also give you more of a colour managed workflow using the full IPP2 system.

Graeme
Click to expand...

Alright, but how does this apply to RWG? Up until now since RWG was announced I've been using RWG/Log3G10 with an output LUT. Should I instead use the output LUT with rec709 color space? Isn't that mapping the colors wrong if the LUT is made from RWG space? How will all this be applied to other software like Resolve? Do you know if they are working to implement all of this? They use to be pretty fast with including new things.
 
Christoffer Glans said:
Alright, but how does this apply to RWG? Up until now since RWG was announced I've been using RWG/Log3G10 with an output LUT. Should I instead use the output LUT with rec709 color space? Isn't that mapping the colors wrong if the LUT is made from RWG space? How will all this be applied to other software like Resolve? Do you know if they are working to implement all of this? They use to be pretty fast with including new things.
Click to expand...

So IPP2 has a number of stages in the pipeline:

1) Primary: take sensor data to RWG/Log3G10 via ISO / exposure, kelvin and tint white balance.
2) Grading: Typically CDL or grading in log space in a grading app
3) Development: Transform RWG into the desired output colour space (say REC709, P3 or REC2020) via a gamut mapping algorithm that stops out-of-gamut colours going funky
4) Output: Takes the developed image (still in Log3G10) out to the gamma of the display, typically BT1886 for a standard dynamic range (SDR) HD monitor or SMPTE2084 for a HDR monitor.

The IPP2 preview cube LUT takes all the math from stages 3 and 4 above (Development and output) and boils it down into a form people could use for testing purposes, or for when the workflow involves grading in a 3rd party application like Resolve.

The IPP2 Preview build of REDCine-X does all the stages using transform math, and thus is flexible and can be configured for different monitor outputs or colour spaces.

Graeme
 
Graeme Nattress said:
So IPP2 has a number of stages in the pipeline:

1) Primary: take sensor data to RWG/Log3G10 via ISO / exposure, kelvin and tint white balance.
2) Grading: Typically CDL or grading in log space in a grading app
3) Development: Transform RWG into the desired output colour space (say REC709, P3 or REC2020) via a gamut mapping algorithm that stops out-of-gamut colours going funky
4) Output: Takes the developed image (still in Log3G10) out to the gamma of the display, typically BT1886 for a standard dynamic range (SDR) HD monitor or SMPTE2084 for a HDR monitor.

The IPP2 preview cube LUT takes all the math from stages 3 and 4 above (Development and output) and boils it down into a form people could use for testing purposes, or for when the workflow involves grading in a 3rd party application like Resolve.

The IPP2 Preview build of REDCine-X does all the stages using transform math, and thus is flexible and can be configured for different monitor outputs or colour spaces.

Graeme
Click to expand...

Yeah, that process is what I've been using with the output LUT. But I'm a bit confused about the preview builds workings. Is it supposed to calculate for a color space automatically? Because I still seem to need an output LUT in order to see a proper image.
Also, did I miss some link to a IPP2 Preview cube? Is that the latest in the Cube development we were talking about earlier?
 
You must log in or register to reply here.
Back
Top