Cinelog - True logspace conversion for DNG and CinemaDNG footage

[Jbowdach]

Once you match the default ACR output gamma it really shows the color separation

Is her shirt a lil green in the resolve version?I do like the color seperation but seems like some excessive green in her face and shirt, or am I just tired. Looking forward to your comparison between visionlog and cinelog. Similar but VERY different at the same time, but hard to explain to someone who doesnt understand log images and manipulation. Loving the new C version, thx for being such a responsive dev

[Jbowdach]

The PFE luts are film gamma so will look a little dark. You can push up the shadows in a node before the PFE to rectify or add a Soft Curve lut. 


BTW, you can use Alexa log-C luts from the ARRI Lut Generator too

How would you describe the soft curve LUTs ? it it a simple soft contrast curve for when u want a light contrast curve but not the typical rec709 normalization? or does it have something to do with soft curving in a specific area, like highlights?

[marekk]

My new raw video graded in Resolve 10 with Cinelog 2.0
http://www.magiclantern.fm/forum/index.php?topic=12663.0

[dmk]

Nice marekk, cool (pun intended) way to draw attention to the blue theme throughout a city. I'm sortof more in the headspace right now of less heavy saturation (not that it's a bad thing in general at all- just where my personal taste is right now), but here it really worked well to make usual city shots stand out and say something interesting and different. Nicely done!

[dsManning]

Loving the new package Andy!  Getting some nice results with a quick workflow now.

One question I have, what is everyone using or what is the preferred method of noise reduction for this workflow?  I'm used to using Neat Video plugin for FCP, but with these nice new PFE LUTs applied, I doubt the ISO profiles in Neat would work out (haven't tested yet, not home).  I imagine this would only be for problem footage at 800ISO+ with the PFE grain distracting from much of the noise at lower ISO footage.


I'm thinking either;
export from Resolve before PFE and use Neat Video then roundtrip back to Resolve, apply a PFE -> Profit
or
run DNG files through ACR first to get rid of noise, regular edits in Resolve with a boost to midtone detail or --blur Y channel to sharpen.

Thanks

[Andy600]

@dsManning - Noise reduction is best done before a PFE. PFE's can enhance noise so I would recommend rendering 4:4:4 Prores or DNxHD Cinelog-C and round-tripping before adding a gamut/PFE etc. Even better, get Neatvideo for OXF and you can do it all without leaving Resolve (denoise > Cinelog-C > PFE).

We also have an ACR version of Cinelog-C coming that uses ACR for the log transform and a lut for colorspace. It's producers a very close match to Resolve. You can even render to BMD Film colorspace (color and gamma) from ACR if you like the look of it but this will let ACR users use the same gamut, ouput and PFE luts that come with the Resolve version or let Resolve users make use of ACR which does have noise reduction . We are also consolidating the ACR version to include all supported cameras in a single pack. This makes it simpler for us to maintain as there will be one pack for Resolve and one for ACR with only the main luts being different.

[Andy600]

@Jbowdach - Soft curve 1 adds soft clipping to highlights and Soft Curve 2 adds soft clipping to highlights and shadows. They are both quite subtle. There will be some other 1D curves in the Lut Bank that will give stronger results but you will always get better results working with your own curve or Lift, gamma, gain controls on a node placed before the PFE or output lut.

[morsafr]

Hi Andy,

I experimented a bit with new Cinelog-C package which I found quite amazing.

There is one point thought for which I need your explanations.

If I open the DNG directly in Rec709 (Color space and gamma) I get this look:



If I use BMD Film 4K plus Cinelog-C and then output to Rec709 using the relevant INPUT, GAMUT and OUTPUT LUTs, I get this look:



Discarding the slight change in exposure, what I found "disturbing" is the color shift between the 2 versions.

Indeed, looking out by my window the "direct Rec709" version looks more realistic than the one using Cinelog-C.

Am I missing something here?

Thanks for your feedback!

PS : here is a single DNG frame if you want to check by yourself:

https://dl.dropboxusercontent.com/u/8741922/M15-1850_000000.dng

[Andy600]

@morsafr - This is purely colorspace related. Try with BMD Film and Blackmagic's BMD Film to Rec709 lut - they don't look the same as the default Rec709 profile either, neither would Visionlog to Rec709 etc. BMD Film and Cinelog-C are wide gamut profiles and Cinelog-C has some unique colorspace changes. Cinelog-C is not intended to match the default Resolve Rec709 colorspace. We use standard gamma transfer functions (the same as you will find in OpenColorIO, CTL etc) to get to Cineon, Rec709, sRGb etc but color will be unique. We include the monitor luts purely as a viewing lut when white balancing your image but included the separate sRGB/Rec709 gamut and gamma luts to give you choices as each one can affect the look differently.

If you just want photometrically true color (or the color that chart manufacturers deem as true) then you need to use a chart and color match to it but that's not what Cinelog-C is really about plus even that will not match what you see in the default Rec709 gamma/colorspace.

We can provide you with luts if you want to keep the default Resolve Rec709 look but most users/colorists hate that and it will make most of the other luts we provide unusable.

BTW, you need to white balance your image through the monitor lut if you are using Cinelog-C and not just use a white balance default or the settings you used in the default rec709/rec709 profile

[morsafr]

Thanks Andy for your feedback.

Indeed my dream is not copying Rec709 

Cinelog-C is a great tool as it will allow us to save a considerable amount of space keeping only ProRes 4444 instead of cDNG. But before jumping into it, I'd like to be sure I can get realistic results if I want/need to.

So let me rephrase my point this way: let's say I'm shooting nature/landscapes and I want a realistic colors, what is the best way to proceed using Cinelog-C?

By the way I have a X-Rite Colorchecker that can work with the new Colormatch function in DR 11. If this is the solution for what I'm looking for, where in the workflow should I use it?

Thanks again for your precious advices!

PS: concerning white balance, I try to adjust it the best I can but as I'm using a Wide gamut display (useful for stills) so this is somewhat approximative...

[Andy600]

@mosafar - Ok, that's easy. I will describe it using clip nodes to apply the luts 

Shoot your chart, making sure it is evenly lit and not directly reflecting the light source. Try to set the white balance as accurately as you can.

Load your shot into resolve but DO NOT alter white balance at this stage. (Set it to custom but don't change anything yet).

In Resolve:

Set Resolve to BMD Film 4K gamma/BMD Film colorspace

add 3 nodes

add the BMD Film 4k to Cinelog-C Type 2 lut to node 1

add the 1D Rec709 output lut to node 2

on node 3, select the Colormatch panel and set source AND target gamma and colorspace to Rec709. Line up your chart and hit the match button without altering the target temperature.

You should now have a pretty good chart match.

You can then remove node 2 (the one with the output lut) and add another 2 nodes after the colormatch node. On the last node, re-add the Rec709 output lut and on the node before it you can do your color grade, or just leave it as-is.

I've experimented a lot with the Colormatch tool. It's 'ok' but you really have to be careful with how you light and shoot the chart. If it's unevenly lit, even slightly, it will not work well.

You should, in theory, also be able to select Cineon as source gamma because Cinelog-C is Cineon gamma but it doesn't work atm in Colormatch. I'm not sure Cineon gamma (in Colormatch) is correct but we're looking into it (my guess is that it's the difference between 1.7 and 2.2 gamma).


Does your monitor let you select an output profile (Rec709, sRGB etc) or can it use luts? For video, you should really be monitoring in the colorspace you intend to output to and your monitor should be calibrated as well as possible.

[marekk]

.. I know I talking about two different products but.. what is the best way to go from Cinelog-C to Osiris LUTs ?

[Andy600]

.. I know I talking about two different products but.. what is the best way to go from Cinelog-C to Osiris LUTs ?

TBH this is a minefield. It all depends on what source gamma and colorspace those luts were designed for and their interpretation of it.
 
I don't have the Osiris pack but I see it comes with log and Rec709 flavors. I presume this is input gamma!?. If the log versions expect a Cineon log input you should be able to use those but it might expect VisionLog input. You may be better off getting Cinelog-C into Rec709 gamma using the Rec709 output lut and use the Rec709 Osiris luts. Results will also depend on the input colorspace so you may also need to add the Rec709 or sRGB gamut lut before the Rec709 output lut but you might also get some nice/unexpected results using Prime RGB or Prime Cine RGB.

I will have a proper look at their luts soon and make some Cinelog-C conversion luts if necessary. I would do it now but I'm tied up with getting the new website ready for the Cinelog-C release.

[timbytheriver]

We also have an ACR version of Cinelog-C coming that uses ACR for the log transform and a lut for colorspace.

@Andy600 I am very excited about this!

[Andy600]

@Andy600 I am very excited about this!

Just got a little more testing to do then I'll send you the Cinelog-C ACR pack

[morsafr]

@mosafar - Ok, that's easy. I will describe it using clip nodes to apply the luts 
...

Thank you so much Andy, the result is impressive, very realistic colors + the benefits of Cinelog-C

Just one complementary question: what to change in the workflow if I want a sRGB output gamma instead of REC709?

Does your monitor let you select an output profile (Rec709, sRGB etc) or can it use luts? For video, you should really be monitoring in the colorspace you intend to output to and your monitor should be calibrated as well as possible....

I have several preset modes on my DELL U2711. I'm using the preset mode called "Custom color" to calibrate the monitor to its native gamut (perfect for photography).

I also noticed a preset mode called "sRGB". Should I switched to it, create a new ICC profile with my i1 Display Pro and use this combination as my starting point for Resolve (and switching back to the other preset mode/ICC profile for Lightroom)?

Thank you so much for taking the time to answer all our questions!

[Andy600]

Thank you so much Andy, the result is impressive, very realistic colors + the benefits of Cinelog-C

Just one complementary question: what to change in the workflow if I want a sRGB output gamma instead of REC709?
I have several preset modes on my DELL U2711. I'm using the preset mode called "Custom color" to calibrate the monitor to its native gamut (perfect for photography).

I also noticed a preset mode called "sRGB". Should I switched to it, create a new ICC profile with my i1 Display Pro and use this combination as my starting point for Resolve (and switching back to the other preset mode/ICC profile for Lightroom)?

Thank you so much for taking the time to answer all our questions!

You're welcome

For colormatching to sRGB just repeat the process but swap the output lut to sRGB and select sRGB as source and target gamma. There is no sRGB colorspace target in Resolve as it's essentially the same as Rec709. Only the gamma changes but the gamma change affects the appearance of color (i.e in this case it gets lighter). The Cinelog-C Rec709 and sRGB 3D gamut luts should be used with their Rec709 and sRGB 1D output lut counterparts but we kept them separate so you can mix 'n' match if you so choose. Mixing will not be totally accurate but, for instance, adding the rec709 gamut lut to a BT.1886 output lut can produce deeper color than you would usually see with sRGB. You don't necessarily need to add a gamut lut for technical reasons or even use them at all. They can also be used to saturate/desaturate an image or let you increase relative color saturation to greater extremes.

re: your monitor. You should be able to create a Rec709 or sRGB profile with your i1 and leave the monitor in wide gamut!? This should be better than the sRGB preset (they are usually quite bad) but I don't know the actual monitor so I can't say for sure. 

[marekk]

TBH this is a minefield. It all depends on what source gamma and colorspace those luts were designed for and their interpretation of it.
 
I don't have the Osiris pack but I see it comes with log and Rec709 flavors. I presume this is input gamma!?. If the log versions expect a Cineon log input you should be able to use those but it might expect VisionLog input. You may be better off getting Cinelog-C into Rec709 gamma using the Rec709 output lut and use the Rec709 Osiris luts. Results will also depend on the input colorspace so you may also need to add the Rec709 or sRGB gamut lut before the Rec709 output lut but you might also get some nice/unexpected results using Prime RGB or Prime Cine RGB.

I will have a proper look at their luts soon and make some Cinelog-C conversion luts if necessary. I would do it now but I'm tied up with getting the new website ready for the Cinelog-C release.

There is a special lut for Cinelog 2.0 to convert footage to Alexa Log C. Is it possible to create conversion lut for Cinelog-C (>Alexa Log C)?

[Andy600]

There is a special lut for Cinelog 2.0 to convert footage to Alexa Log C. Is it possible to create conversion lut for Cinelog-C (>Alexa Log C)?

The Log-C formula is really only useful for the Alexa and it's 15+ F-stops of DR. Log-C is actually based on Cineon but converting to Log-C will be wasting a lot of space. The only real difference between Cinelog-C gamma and Log-C is in the scaling. Cinelog-C is scaled to work better on lower DR cameras (up to 13.5 f-stops) but has the same black and white points. You can even use normalized Alexa Log-C luts if you like .

Basically, you already have it with Cinelog-C + some 'Alexa'esque' color tone and color separation!

[marekk]

The Log-C formula is really only useful for the Alexa and it's 15+ F-stops of DR. Log-C is actually based on Cineon but converting to Log-C will be wasting a lot of space. The only real difference between Cinelog-C gamma and Log-C is in the scaling. Cinelog-C is scaled to work better on lower DR cameras (up to 13.5 f-stops) but has the same black and white points. You can even use normalized Alexa Log-C luts if you like .

Basically, you already have it with Cinelog-C + some 'Alexa'esque' color tone and color separation!

Thx Andy I'm not a color grading expert I would like to simply add some color effects to my footage I'm trying to figure out how to achieve the same look with Cinelog-C as with Cinelog 2.0 -> Arri Log C -> Rec709 -> OSIRIS Luts

[Andy600]

Thx Andy I'm not a color grading expert I would like to simply add some color effects to my footage I'm trying to figure out how to achieve the same look with Cinelog-C as with Cinelog 2.0 -> Arri Log C -> Rec709 -> OSIRIS Luts

Ok, try BMD Film 4k to Cinelog-C + sRGB gamut lut + Rec709 or sRGB 1D output lut (this will give you color and gamma close to the previous version but you will probably need to increase exposure in the camera raw panel to about 0.75) then try adding an Osiris Rec709 Lut.

Then try swapping the gamut lut Prime Cine RGB might give you some nice results. Reduce or increase colorboost and/or saturation to your own taste.

[QuickHitRecord]

@Andy600

I am trying to nail down a workflow. I'm looking to use Resolve 11 to export LOG clips that are as close to Alexa in-camera LOG as possible, then edit, then re-import into Resolve and apply FilmConvert and make secondary adjustments. How does this look to you?

1) Configure Project Settings: Camera Raw (CinemaDNG/Decode Using Project/ColorSpace: BMD Film/White Balance if same lighting conditions for entire project)

2) Configure Project Settings: Look Up Tables (3D Input Lookup Table: Cinelog-C)

3) Apply NeatVideo to first node in each clip

4) Export all clips (ProRes HQ)

5) Edit

6) Import timeline into Resolve

7) Apply FilmConvert (Source Camera: Alexa Log-C Film)

8 ) Adjust secondaries

9) Export

[Andy600]

@QuickHitRecord

Ok, a couple of things I would suggest.

1) Select BMD Film 4k gamma/BMD Film colorspace for ML footage (you may already do this but just to be sure ). Also, add the Rec709 or sRGB monitor lut in the Monitor Lut slot of the Lut Panel. It makes it easier to white balance. This lut does not get rendered.

2) Use the BMD Film 4k to Cinelog-C input lut (it will add a bit more color separation and creamier skintones than the Type2 version)

3) Yes (I also switch on Node Cache if I'm using NeatVideo)

4) Yes, although 4:4:4 is a better option if you can afford the disk space

5) Yes, you can add a monitor lut again when editing in another NLE if you don't want to look at a log image.

6) Yes

7) If you are choosing Alexa Log-C Film as the input profile for FilmConvert you should add the Alexa Film Matrix gamut lut on a node before FilmConvert (The Film Matrix will add saturation back to the image and is basically the same as you would do with the Alexa). Adjust the FilmConvert curve and film color to taste.

Yes - I usually use a layer node to qualify the skin tones then apply the inverse selection to the second layer and mix using key level. You can also use outside nodes to do this.

9) Yes

Resolve 11 Tip: Play with the new midtone detail (in the Colormatch panel) on the same node where you have added FilmConvert. It can make the image a touch more filmic.

[morsafr]

@mosafar - Ok, that's easy. I will describe it using clip nodes to apply the luts 

Shoot your chart, making sure it is evenly lit and not directly reflecting the light source. Try to set the white balance as accurately as you can.

Load your shot into resolve but DO NOT alter white balance at this stage. (Set it to custom but don't change anything yet).
...

Hi again Andy,

I forgot to ask you about something: if I need to adjust white balance within the Colormatch workflow, when can I do it?

More generally, If I want to change the Camera RAW settings, what is the best way to do it?

Thanks again!

[timbytheriver]

Just got a little more testing to do then I'll send you the Cinelog-C ACR pack

*Waits by Postbox patiently*