gamma 2,2 - still don´t get it

[rikou]

the reason I think there is so much confusion is because I have seen 100 ways people are doing it. I found something that worked for me, and I stopped being concerned about it....

Totally agree with you !
AFAIK, it's the most important, no ?

[pailhead]

but to save correctly to exr you need to render with Don’t affect colours (adaption only) checked right? When I'm rendering without it and saving exr it's adding extra gamma correction.

Won't this just help get better sampling? You can leave gamma at 1.0.

[pailhead]

BTW

The reason i think there is so much confusion about this subject is my belief that only a handful of vray (and 3d in general) users actually work in linear, hence having a linear workflow. People like Chris Nichols, Morbid Angel etc probably have a linear workflow. Probably 99% of the arch-viz people who predominantly use vray, think that they may understand it but they don't.


Can photoshop even work in linear?


Say i save my images with a certain gamma value and everything looks dark and over saturated - exactly the same as it would before and after ticking the sRGB in VFB. Say I import all those layers into photoshop, and then on top of the layer stack i put a gamma correction layer and set it to 2.2.

Any blur/blending/whatever will look different, and more correct than the way you normally worked.

Am i on the right track?

[voltron7]

I've been using the button lately. I saw a video by (I think Svetlozar) that I liked so I have been using it lately and am happy with the results...FWIW, I don't do much more than some simple photochopping...

So, here is the thread I had seen the video by Svetlozar...
http://www.chaosgroup.com/forums/vbu...onitor+display

[glorybound]

and, I don't think many casual users save as an 32bit EXR.

[Zdravko]

So if we're telling max to use gamma 2.2 on sRGB bitmaps its only an approximation into linear

Yes. But the difference between sRGB curve and 2.2 is insignificant and the 2.2 approach is much easier to calculate.

[samuel_bubat]

BTW
The reason i think there is so much confusion about this subject is my belief that only a handful of vray (and 3d in general) users actually work in linear, hence having a linear workflow. People like Chris Nichols, Morbid Angel etc probably have a linear workflow. Probably 99% of the arch-viz people who predominantly use vray, think that they may understand it but they don't.

That´s exactly the point ! As far as I can judge 99% use it to brighten up their scenes like described in dozens of terrible tutorials.

This is just one great example what linear workflow is NOT about.
http://www.workshop.mintviz.com/tuto...y-and-3ds-max/

you can read things like this....
---
"Up until now, you are used to adding in extra lights and hitting a high multiplier value in order to get light to flood through your scene and eliminate dark areas. However, this can lead to incorrect burnt out areas. Gamma correction fixes this problem and allows you to reduce the amount of lights in your scene,
---
sorry for raging a bit... but what an utter nonsense ! It´s not incorrect at all, that´s simply the way a physical camera behaves.
A physical camera does two things. It clamps your range depending on exposure settings and it renders an absolute linear curve.
(speaking in rgb values)
There´s no way to alter the curve itself within the camera controls.
This is a problem for interior scenes, because of either burned out areas or to dark corners.
A color mapping like reinhard used without a physical camera can produce what ever you want from the whole color/intensity range of your scene.
Used with default values will give a linear curve as well. Adjusting the Multiplier is similar to an exposure control of a physical camera
Burn value and gamma shapes your curve. So you can precisely adjust how your scene looks like.

With a color mapping like reinhard or log. exposure. you can get a cathedral lit just by a candle bright as daylight
without any burned out areas, harmed multipliers, extra lights or gamma adjustment.
Also using color mappings to adjust interiors is as old as Lightscape.

[MoonDoggie]

No need to apologize for the rage. I started it.

[trixian]

To be honest, I think I know where this sentiment about lighting comes from. Back in the days, when most people were completely oblivious to the whole LWF and gamma stuff, we all fought against really weird lighting and colouring issues and we never once got a good answer from anyone (even the developers that put the mysterious gamma stuff in max's settings).
For many of us, it was more a matter of suddenly being able to light our scenes without having to do strange fixes and hacks and avoiding all the awful saturation and burnouts, or fiddling with insane settings for the lights falloff ranges etc. The fact that suddenly all the maths behind the image were more "correct" and enabled us to comp better was just a happy side effect. Back then, there was no such thing as EXR. The only reliable float format available was rpf, and was insanely heavy, and mostly worked in Discreet logic's comp suites like Edit/Paint and later Combustion.
What really baffles me is that all these developers wrote the whole gamma stuff into their programs from the start seemingly without knowing why, or at least never informing the users.

[PIXELBOX_SRO]

that really reminded me those times Christian, thats spot on
i really hated it back then BTW

[lukx]

After all this thread I'm starting to think I really don't get LWF .
Basically let's assume you do everything right way so :
affect color on, save to exr. Now you open the file in PS and got the exposure slider to adjust it to your liking. But it's simply adjuts whole exposure and you still might get burnouts or to dark things. Plus when you adjust it how to save it to jpg? Or how to adjust parts of image is it possible? I'm really curious how Bertrand do it cause he's using this affect color thingy.

[Morne]

to save to jpg you have to go to image > mode > 8bit
than you can save as jpg
(but keep a 32bit copy in case you want to go back and change stuff)

to effect only parts of the image, either use masks, or just duplicate the layer and then adjust exposure, then erase parts you dont need on this layer, so that the original exposure shows on the bottom layer

[lukx]

Morne, but when changing mode I'm getting some adjustment window pop up that's changing all things.

[joconnell]

http://www.workshop.mintviz.com/tuto...y-and-3ds-max/

you can read things like this....
---
"Up until now, you are used to adding in extra lights and hitting a high multiplier value in order to get light to flood through your scene and eliminate dark areas. However, this can lead to incorrect burnt out areas. Gamma correction fixes this problem and allows you to reduce the amount of lights in your scene,
---
sorry for raging a bit... but what an utter nonsense ! It´s not incorrect at all, that´s simply the way a physical camera behaves.
A physical camera does two things. It clamps your range depending on exposure settings and it renders an absolute linear curve.
(speaking in rgb values)
There´s no way to alter the curve itself within the camera controls.

There's some truth in the above.

The whole reason for linear workflow, is that your monitor is not displaying your image in a linear fashion. It's darkening the mid tones of it and while your software is calculating everything totally correctly, your monitor is not showing you this. That's all.

[glorybound]

the only thing I am still confused about is, importing textures. If an HDRI is 2.2, and my MAX is set for input 2.2, is it applying a curve again? Or, if it is 2.2 it'll leave it alone, and if it isn't it'll apply a curve. Should we assume all images are 2.2?