controling white balance problem

[lukx]

What are the tricks to control precisely white balance. For example lets say I'm using some morning sun HDRI to light the scene. I'm getting orange color cast in interior. Now I'm setting camera temperature to get rid of orange and have neutral grey on white walls. But it's hard to get it right there's always some color cast, bluish or yellowish. I'm tryuing to achieve grey color as Bertrand in his White Vicarage work: http://www.flickr.com/photos/bbb3viz...57632462224257

[Morne]

Have you tried the "white ball" approach?
Stick a large white ball in the middle of your scene and render. Right click on the brightest spot on the ball and measure RGB. Use that as value as your rgb white balance and rerender. Your white should now be white

[tricky]

Have you tried the "white ball" approach?
Stick a large white ball in the middle of your scene and render. Right click on the brightest spot on the ball and measure RGB. Use that as value as your rgb white balance and rerender. Your white should now be white

This is the method I use too. Be careful that your camera that you rendered the white ball is set to neutral though.

Another thing to consider is that you don't always necessarily want your image to be completely balanced. Sometimes a bit of warmth or coolness can be good.

[lukx]

Thank you guys! Will do. Just one thing. If I'm not setting my white walls to white white 255.255.255 but 200.200.200. should I also set the ball the same?

[Morne]

Thank you guys! Will do. Just one thing. If I'm not setting my white walls to white white 255.255.255 but 200.200.200. should I also set the ball the same?

Yes I would set the ball the same (200,200,200)

[yyk]

It might be pretty hard to get rid of all color variation via whitebalance because HDRIs usually have a pretty wide range of color. Why not desaturate the HDRI instead?

[samuel_bubat]

Just a wild idea.. but if you want the lighting to be absolutely without color.. why not use color correction in front where you turn down saturation completely ?

edit: yyk was faster

[tricky]

As long as your 'ball' is neutral and you pick that with a neutral camera, you have white balanced. However, as others have said, scenes with a complex mix of lighting (daylight/fluro/tungsten/hdr etc) will be difficult to balance completely. Just the same, in fact, as with real world photography.

[glorybound]

I read a good trick, but it's done in post.

find middle gray in your scene

create a new layer
fill it with 50% gray
change blending mode from normal to difference
add a threshold layer
move the slider to the left and slowly slide to the right until you see black
sample it by holding shift
delete the threshold and the 50% gray layers
get the RBG value of your sample (info window)
average your RGB numbers
apply a curve
go to red, green, blue
pick a point on the curve and nudge to average

[fxi]

from the comments:
Lighting is just one Peter Guthrie HDR map. It is desaturated in Photoshop,

http://bertrand-benoit.com/blog/2013...#comment-40469

[joconnell]

As long as your 'ball' is neutral and you pick that with a neutral camera, you have white balanced. However, as others have said, scenes with a complex mix of lighting (daylight/fluro/tungsten/hdr etc) will be difficult to balance completely. Just the same, in fact, as with real world photography.

Bingo - most photographers tend to see which is the easiest light source to either remove or gel towards the dominant one.

[danb4026]

Depending on you scene, sometimes turning up the GI multiplier in Vray properties for the object could dissipate some of the color cast. It will brighten the object up though.