Author Topic: Time to ditch sRGB/Linear as default (?)  (Read 34462 times)

2017-02-22, 18:32:01
Reply #60

Dionysios.TS

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Guys (especially Rawa), please restrain from personal fights, or switch to private messaging. This thread is to discuss specific topic, there is no point in adding the extra spam.

How is my recent post a personal fight?

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2017-02-22, 20:07:25
Reply #61

bluebox

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Guys (especially Rawa), please restrain from personal fights, or switch to private messaging. This thread is to discuss specific topic, there is no point in adding the extra spam.

Funny. I see this exactly the opposite way :)
Rawalanche is trying to bring up a case with which everyone seems to agree with (myself including) presenting rational arguments, while Njen goes like "trust me, I'm an angineer , what you say is wrong and I know this cuz I'm an engineer" :D absolutely failing to acknowledge that Rawalanche is not proposing to make Corona unusable in classical VFX pipeline BUT instead to work by default like a DSLR with the option to work like it does now after activating a checkbox. Win-win situation.
No offence guys, with all the respect to your amazing knowledge, what you achieved and worked on (this is not irony), leave your egos outside the door please :)

Personally after watching that lecture about ACES I'm all for the change. It simply looks so much better and easier. If it would help even a tiny bit in fighting constantly too dark renders then please do it :)

2017-02-22, 21:39:16
Reply #62

Adanmq

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Hi.

In my personal opinion this is a complex subject that can help Corona conquer an specific sector of the market (people that need/want easy/good results out of the box) but will leave Corona outside other markets like VFX (yes, most VFX studios use LWF). Looks to me that this is already your strategy and it´s working really good so far but i´m also sure you know about the "side" effects.

ArchViz studios probably will love this change because right now we are making this (not everyone) using compresión + custom LUTs (it´s not the best way to do it in my opinion) and can be confusing for a lot of people new to the industry. But i personally think it´s a mistake if you can´t choose, i prefer linear renders because they are important not only for multi pass compositing. You need linear data for comp in order to do a lot of things property like DOF, MB, Glints Glares, etc. and we usually use OCIO or LUTs just for pre visualice the end result but still working in linear during the entire pipeline. Comp operations still linear. If the user can choose i think it´s a good move xD

But i can understand why this can help Corona to conquer the ArchViz market since most ArchViz artist don´t really understand whats LWF or how to use tone mapping properly.

¿And what do you want to use instead linear? because i suppose Corona will keep making light calculations in a linear way so we are talking about some short of internal post-production i can´t control? Something like Shaper Log LUT + Filmic Contrast LUT?  will we have several contrast or camera response choices?

About the video from BG i think it´s not really accurate and can make some people misunderstand the problem/solution. Because most of the people are shocking about the "magic" button instead of really understanding what´s going on.

Of course this is only my personal opinion.


PD: if you want to replicate this "magic button" from the video just download the OCIO and use it to color management a Nuke viewer or if you really want to break your 32bpc file and transform it into a 16bpc tonemapped one transform your render into Log using nuke lin2log and apply the LUT from the OCIO pack you can also download OCIO profiles from Sony from the web site. This is nothing new to the industry as Rawalanche pointed, this is old stuff xD

Some people ask me for this on my channel and i make this examples to explain the process (they are in Spanish sorry):

https://www.flickr.com/photos/adanmq/32187170644/in/photostream/lightbox/
https://www.flickr.com/photos/adanmq/33032436735/in/photostream/lightbox/

Best.
A

« Last Edit: 2017-02-22, 22:16:28 by Adanmq »

2017-02-22, 22:27:14
Reply #63

agentdark45

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Some people ask me for this on my channel and i make this examples to explain the process (they are in Spanish sorry):

https://www.flickr.com/photos/adanmq/32187170644/in/photostream/lightbox/
https://www.flickr.com/photos/adanmq/33032436735/in/photostream/lightbox/

Best.
A

This might be a silly question, but are you able to compile the above processes into one singular LUT file that we can use in the Corona VFB so we can test this out? Would make life a lot easier than having to fire up Nuke. Is this even possible using LUT's in Corona? I'm still kind of noobish with LUT's and their limitations.

Cheers
Vray who?

2017-02-22, 22:56:00
Reply #64

Adanmq

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This might be a silly question, but are you able to compile the above processes into one singular LUT file that we can use in the Corona VFB so we can test this out? Would make life a lot easier than having to fire up Nuke. Is this even possible using LUT's in Corona? I'm still kind of noobish with LUT's and their limitations.

Cheers

HI

You can´t. LUTs are only able to map 0-1 values that´s why you need to apply a "shaper" LUT (lin2log) before in order to re-map the linear values into a logarithmic 0 to 1 format and then apply the contrast LUT to this 0 to 1 logarithmic file. The OCIO "magic trick" apply this 2 LUTs in a row.

But you don´t need to do this in Corona, you already have amaizing tone mapping inside Corona, you can "skip" this lin2log because you can compress dynamic range using highlight compression for example, try this LUT but you need to apply heavy highlight compression in order to use it. But i recomend to undertand whats going on being before you start using this kind of stuff xD

Or you can tick "input LUT in Log space" and use the LUT from the OCIO package.

I edit to add the "Heavy contrast" LUT from the original Filmic Blender OCIO transformed into a Cube LUT so you can use (This needs to be used in Log space)


Best.
A

« Last Edit: 2017-02-22, 23:21:33 by Adanmq »

2017-02-22, 23:40:11
Reply #65

Ludvik Koutny

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This is great!

Could you convert other contrast curves into .cube LUTs too? The very hard one you did works very well! :)

2017-02-22, 23:51:28
Reply #66

Adanmq

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Sure here you have the whole pack xD Just use Log and you will get the exact same result as in the famous video xD

Usually you need to increase the exposure in order to get proper midtones.

Best.
A

2017-02-22, 23:53:08
Reply #67

Ludvik Koutny

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Thank you very much!

Yes, I figured, I just could not find a way to convert spi1d to .cube, as I don't work with LUTs much.

2017-02-23, 00:12:15
Reply #68

melviso

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The Blender tut about filmic blender did offer explanations about some issues I have had with lighting and materials. Reason why I use lights for my scenes rather than HDRI and some tweaking to get the colors to look right within certain context. This is actually a good thing as a lot of ppl are now discussing it and devs are also looking into it as well.

As for the thread topic, If we can have both and there is no loss in quality or features that come with sRGB (I do admit using this gives you some sort of control). Then it can be done. If nope, maybe two versions of Corona, one filmic and another sRGB.

2017-02-23, 00:36:19
Reply #69

Dionysios.TS

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Sure here you have the whole pack xD Just use Log and you will get the exact same result as in the famous video xD

Usually you need to increase the exposure in order to get proper midtones.

Best.
A

Thanks for sharing these... :)
The VFB Corona contrast in this case is set to default 1.0?

Thanks in advance,

Dionysios -
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Renzo Piano Building Workshop / Paris

https://dionysios.myportfolio.com/

2017-02-23, 01:02:34
Reply #70

agentdark45

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HI

You can´t. LUTs are only able to map 0-1 values that´s why you need to apply a "shaper" LUT (lin2log) before in order to re-map the linear values into a logarithmic 0 to 1 format and then apply the contrast LUT to this 0 to 1 logarithmic file. The OCIO "magic trick" apply this 2 LUTs in a row.

But you don´t need to do this in Corona, you already have amaizing tone mapping inside Corona, you can "skip" this lin2log because you can compress dynamic range using highlight compression for example, try this LUT but you need to apply heavy highlight compression in order to use it. But i recomend to undertand whats going on being before you start using this kind of stuff xD

Or you can tick "input LUT in Log space" and use the LUT from the OCIO package.

I edit to add the "Heavy contrast" LUT from the original Filmic Blender OCIO transformed into a Cube LUT so you can use (This needs to be used in Log space)


Best.
A

Thanks for taking the time to explain this further and for providing the files! I think I've got my head round this a bit more now.

*edit*

We are definitely onto something here. I've just plugged in the medium high contrast cube file in log colour space into a test scene I'm working on and wow what a difference! I reset all of my tone-mapping settings that I thought looked pretty good and damn, the burnouts on some wooden shutters in the window have been completely subdued (you can actually see the individual shutters now and the exterior brightness has been tamed) while retaining great contrast, colour saturation and shadow depth elsewhere in the scene. No "murky grey" tones anywhere.

Will need to do some serious testing of this workflow as now some of my materials are a bit too vibrant.
« Last Edit: 2017-02-23, 01:48:36 by agentdark45 »
Vray who?

2017-02-24, 02:00:25
Reply #71

philipb

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Just need a quick reality check here.....

At the end of the day this is really just a discussion about tonemapping, right? (excluding all the comping discussion)

Just the idea that an HDR/32 bit linear render benefits from some form of tone mapping before being passed to the Srgb display transformation?   I know it can get deeper than that, but at its essence that is what all this is essentially about, and all the hubbub from that blender guru guy?




2017-02-24, 03:41:31
Reply #72

astudio

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Fully agree with Njen.

Photoshop's Autotone Autolevels Autocolor buttons are for non professional users. It's not me, it's Den Margolis ;)
As I understand you want to make using such button by default. Strange way of thinking as for me.

You may add such button (as Photoshop), or at least to give to user possibility to choose what default he would like.

The main question is not "What to do?", but "To do or not to do?".

PS. The battle Nikon-Cannon-Corona will be funny.

PPS. They are not stupid in Adobe. Don't change the default.

2017-02-24, 11:01:20
Reply #73

romullus

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I tried Adanmq's LUTs on few of my scenes and i have mixed feelings about it. The results i got, is pretty unreliable - in some scenes these LUTs works good, in others, not so much. Besides, it seems that once i use Adan's LUTs, Corona's tonemapping controls becomes useless. I rarely feel the need to tweak my renders further outside of VFB, after i use Corona's tonemapping, but with these LUTs i have to send every picture to photoshop to tweak something. Maybe it's just my inexperience. I'll try to play with it more and see if i manage to get more consistent results.

Curious what others think about Adan's LUTs?
I'm not Corona Team member. Everything i say, is my personal opinion only.

2017-02-24, 16:32:34
Reply #74

Adanmq

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I tried Adanmq's LUTs on few of my scenes and i have mixed feelings about it. The results i got, is pretty unreliable - in some scenes these LUTs works good, in others, not so much. Besides, it seems that once i use Adan's LUTs, Corona's tonemapping controls becomes useless. I rarely feel the need to tweak my renders further outside of VFB, after i use Corona's tonemapping, but with these LUTs i have to send every picture to photoshop to tweak something. Maybe it's just my inexperience. I'll try to play with it more and see if i manage to get more consistent results.

Curious what others think about Adan's LUTs?

HI.
The LUTs that comes whit corona are just a color response and they are not standardized for any specific workflow so they are designed to be used in an "artistically" way and usually you need to do exposure, compresión and contrast separately to achieve final results.

LUTs are not a good way to grade a linear image to be honest, I personally only use contrast ones + highlight corona compresión in order to be able to better see the linear render on a sRGB monitor so i can work on lighting/materials whit something similar to the final post in mind but i usually do my post by hand. LUTs are great to color management between apps and platforms. LUTs needs some short of compresión before you apply them or you will kill your render and clamp the results.

The ones y post here are just a conversion from the original Filmic Blender thing and they only give you a contrast reference but you need to use them in LOG and help you pre-visualice your linear image on a sRGB monitor so you can better plan your materials/light.

I´m working on a new pack designed to be uses over compressed linear renders because even if LUTs are not designed for that purpose a lot of people are using it for it and it´s better if you have proper designed ones xD

Best
A