2Zillah: removing orange tint with WB

B0rG

Zillah wrote:

Could you take a picture of a typical orange street in Dublin and use an appropriate WB setting to have it come out in true colour? I don't think its possible but I'm open to being convinced.

After my recent conversation with Zillah I could not really avoid making the point that I'm kinda difficult to argue with because well... I'm always right.

So I uploaded two pictures.

1. is to illustrate the point that yes you can really correct the yellow tint with white balance correction. Just move the color temperature slider to the left.

2. Some people may be recognised on that picture. It's too far away, so we can't really see that 5D he's wearing

You can of course argue that I replaced the orange color cast with blue color cast, but in order to do finer adjustments you'll have to use curves: isolate the yellow light color range and make it cooler.

bp_me

Only easily when shooting in raw of course.....

B0rG

Anybody not shooting in raw?

Zillah

Cos this was so worth a whole thread of its own. Those aren't the street light I'm talking about. I specifically said the orange ones, like those found across the suburbs, like so:



Forgive the super-graniness, I just shot it now at 1600ISO for simplicity. That was what it came out like with the WB set to Auto and Tungsten. Do you think you could WB that to normality with the RAW?

EDIT:

And for my own amusement I'll point out that what you did had absolutely nothing to do with RAW or WB. I achieved the exact same effect in ten seconds using Channel Mixer on the jpeg of the original above (well, I think I brightened it a tiny bit too much but I couldn't be bothered redoing it). So neh neh :

B0rG

didn't want to highjack someone elses thread

You did overburn the light on the left column but given it was screen capture from Jpeg, it's allowed. Same effect can be achieved using curves.

PaulieC

B0rG wrote:

Could you take a picture of a typical orange street in Dublin and use an appropriate WB setting to have it come out in true colour?

Surely the true colour is the colour that they appear to the eye i.e. orange ?

B0rG

true color is the one you can measure with spectrophotometer - it gives you exact wavelength of the color it measures. From there you can work out any colorspace values: rgb, cmyk, lab, etc.

Another option is to have trained painter eye - after years of training in mixing colors by hand they are able to tell the true color.

Untrained human eye compensates for the background lighting and other factors (you can say exposure metering) and gives your brain a signal about the color. The thing is it's not necessarily the true color.

PaulieC

ok, why is everyone obsessed with orange-tinted images not appearing as white-tinted ? If I walk around the city at night time, everything has an orange tint. Surely if an image has this tint, then the white balance is correct as it's recorded exactly was there?

Zillah

I agree, I just think the orange is hideous.

PaulieC

I do too, but that is the colour of stuff at night...