How to get better VRay renders (aka working in linear space)

[Dman3d]

Think the do-dad he is talking about is in the winxp update area, have to look around to be sure.

[mmikee]

Wow, Excellent thread. I have adopted this workflow and have started seeing faster render times. I opened an earlier scene and "converted" it to match the linear work flow, and it renders about
20 % faster with much better results.

Thanks to all who contributed to this thread.

Regards,
Mike

[skogskalle]

oookay... I just got my EyeOneII display colorcalibration thingy today and thought I should try this linear space thing.

got a couple of questions.

1) I use a LCD monitor. Ive been reading in this thread that LCDs have very different gammasettings than CRTs. Should I still calibrate my LCD to gamma 2.2? or should I use some other value?

2) How do I know what "white-point" to calibrate to? Ive read that some people use 5500 , but is that good for all monitors? (I think the default value of my EyeOneII is 6500)

3) Ive never used the colorcorrect plugin. But if Im using the linear space B workflow (gamma correction through vrays colormapping), I have to apply this colorcorrect plugin to all my textures made in photoshop, or downloaded from the web? But I dont have to use it on simple colors? right? or am I way off here?

sorry if these are stupid questions... I have never calibrated a monitor before and I really dont know crap about it , and this thread is so long it made my brain cry trying to read and understand it all.

thanks in advance!

[vlado]

1) I use a LCD monitor. Ive been reading in this thread that LCDs have very different gammasettings than CRTs. Should I still calibrate my LCD to gamma 2.2? or should I use some other value?

From what I understand, you need to calibrate your LCD monitor to act like a CRT one with 2.2 gamma and then proceed as with a CRT monitor applying all the gamma stuff. My Samsung SyncMaster 213T has a program called Natural Color that calibrates the LCD to act like a CRT monitor.

Best regards,
Vlado

[dapeter]

Wow - this works great. I don't know why I haven't tried it out yet...

Anyway, with Viz 2007 using the 'Enable Gamma Correction' works in the viewport... in the Max vfb, and even when you click on the 'View Image' button in a bitmap material. It doesn't, however, change the gamma on the material previews in the material browser. Of course Viz doesn't have the check box to affect the material browser like Max does.

Am I missing something in Viz?

[n6]

1) I use a LCD monitor. Ive been reading in this thread that LCDs have very different gammasettings than CRTs. Should I still calibrate my LCD to gamma 2.2? or should I use some other value?

From what I understand, you need to calibrate your LCD monitor to act like a CRT one with 2.2 gamma and then proceed as with a CRT monitor applying all the gamma stuff. My Samsung SyncMaster 213T has a program called Natural Color that calibrates the LCD to act like a CRT monitor.

Best regards,
Vlado

Vlado I have too a SyncMaster but its a 204Ts and it comes with the same software adjustement :Natural Color.
I dont anderstand what gamma the software apply to the monitor since the monitor it self has its own gamma value : mine is set to 0.2

Did you mean that with the Natural Color software calibrations then we have something like a linear display? and so there is no need of adjusting the VRay VFB gamma curve?

I have try adjusting this curve but everything I get is a washed out image even with low value such as 0.2.

BUT! when I render as *.vrimg (without any correction) / extract an *.exr and open it in Photoshop I have the same washed out image and in order to get the same visual result as Vray VFB I need to apply a 2.2 gamma in Photoshop

I m realy lost

[n6]

Ok, I still don't get it but I'm hoping I don't have to get it. When you say the above (bold text), can you tell me what people don't work in linear space?

I don't blame you for being confused... it is actually a simple concept, but it took me a while before it "clicked." The first thing that you need to realize, is that your monitor has a gamma curve on it. in the old days, the that gamma curve was all over the place Today, they tried to standardize it. That standard is called sRGB.

So when looking at images, those images have to undertand that there is a gamma curve and adjust how they display the image to compensate for that by applying (invisible to the user) a reverse gamma curve.

Photoshop does it, After Effects does it, they all do it... you just don't realize it. That is because 99.99% of the people that use computers don't need to know.

OK... the Vray frame buffer does not do that. So, all your images look dark. The first thing that people do is to add more light and more fill. That is not a problem unless you open it in Photoshop with an sRGB correction at which point your image will look washed out. The alternative solution is to apply a gamma curve as Throb has outlined in the frame buffer... then when you open it in Photoshop, make sure you are using an sRGB curve. If you would rather add more light and GI, then you need to make sue your are reading into Photoshop with a Linear correction.

I would experiment with that. Make an image in Vray, open it with Photoshop and make sure you are using a sRGB gamma. Look at the difference. Then, apply the sRGB curve to the frame buffer as Throb outlined and see it it matches your image better.

Thanks a billion !!!! I think I have had the "click" reading your post (after 30 reading of all other LWF threads).... thanks thanks thanks

[tricky]

Hey, didn't I meet you and Dan in LA last year? It's hard to tell by only the upper half of your face!

I believe we did meet timmatron - sorry for the delayed response. Can't believe how big this thread has got!

[beestee]

I found that color management tool for setting profiles for dual monitors. It is specifically called "Microsoft Color Control Panel Applet for Windows XP." It is accessed through the control panel under "color" once it is installed. Seems to work very well!

*EDIT* Click here to go to the download page

[BLADE]

In case, someone have problems to download the WinColorSetup.exe. Here is the direkt link for download I found on internet:

http://www.microsoft.com/downloads/i...ColorSetup.exe

[pixelstudio]

Well then

Hi there dear VrayPeople

Well after reading all the linear workflow stuff. i still am left into the dark and not fully understanding it.

To summarize what i do know:
- Adjust you monitor gamma (best way to do with hardware calibration) but by hand will come close. whitepoint set to 6500K and gamma to 2.2.

- In 3dsmax set my gamma/lut to 2.2 also use this value for material editor and input bitmaps. --EDIT-- I now use 1.0 for bitmap input to compasize so that the textures look okey......

Well that reason for this is becooming a bit clearer but i'm left with a couple of question.
For the background, i'm making an animation and i want to do this right soi thought what the *** is all that linear space everyone is talking about. so i began research.After reading Gijs's post that part is reasonable understandable.

But back to my question:

- If i use textures from photoshop. and max uses the 2.2 gamma wont that wash out the colors of the texture. will that mean all of my textures must be adjust(color correct plugin)?

- in vray there are now a couple of color mappings that i can use. well this is getting a bit tricky for me. wich one do i use. what settings do i set. and most important WHY

- after doing the max settings an i render a frame. it renders to dark... ?? (using linear and gamma corrected. default values) do i need to increase lights useing this workflow?

Well hope some1 can get me on the road with this
If i understand it all i'll make an tutorial about this, cause it's getting complicated if you ask me hehe

-- EDIT 02 --
Well after more research this is what i have now:
- in max > preference use 2.2 for gamma and input bitmap
- use colormapping > gamma correction with .454 in the inverse gamma
setting (rc3)
- adjust all the RGB values of diffuse colors using the colorcorrect plugin (sjees an automation script would be nice hehehe)

And renderrrrr the colors look washed out.....



Well much thanks in advance!

Pixelstudio

[Metin_7]

I've got exactly the same thing: washed-out colors after adjusting all the LWF settings. The renders look like there's a double gamma correction: one from my new monitor and one from Max / V-Ray. I've probably not understood it correctly.

[DaForce]

if its looks double gamma'd it could be because your not using the VFB