Using the white balance selector RGB reading

mrnorwegian

macrumors member
Original poster
Apr 8, 2015
75
18
Oslo
Hi.

When using the white balance selector tool in Lightroom I get a RGB readout in the loupe view. How is this helpful? As I understand the closer the three numbers are to each other the more neutral the selected pixel, but if the white balance in the image is off to begin with won´t these numbers be wrong anyway? Can anyone explain how this is helpful when setting my white balance?
 

Alexander.Of.Oz

macrumors 68030
Oct 29, 2013
2,763
9,768
Adelaide, Australia
I may well be wrong, but I always thought it was designed to be used in conjunction with an 18% grey card. The first thing I do when shooting anywhere is to take an image of an 18% grey card, then use that image to set as my custom white balance in camera. I do this for each different light circumstance I encounter.

Once back in Lightroom, I set the white balance from the grey card and apply it to all images under that light source.

There are variances within the numbers you mentioned, but nothing too great to worry about.
 
Comment

mrnorwegian

macrumors member
Original poster
Apr 8, 2015
75
18
Oslo
Thank you. I get the basics that you should use the selector to select a neutral point (and a gray card being a great way of finding one). I just don´t get what I can use the three numbers below the loupe for :)
 
Comment

Alexander.Of.Oz

macrumors 68030
Oct 29, 2013
2,763
9,768
Adelaide, Australia
Thank you. I get the basics that you should use the selector to select a neutral point (and a gray card being a great way of finding one). I just don´t get what I can use the three numbers below the loupe for :)
I don't have it open, but from memory it shows variance of the three (light) colour spectrums, red, green and blue.
 
Comment

mrnorwegian

macrumors member
Original poster
Apr 8, 2015
75
18
Oslo
I don't have it open, but from memory it shows variance of the three (light) colour spectrums, red, green and blue.
Yes, and what I´m having trouble grasping is how seeing those three numbers can help me set the right white balance. I’m thinking the people at Adobe put it in that tool for a reason, but I can´t find a good explanation for it :)
 
Last edited:
Comment

Alexander.Of.Oz

macrumors 68030
Oct 29, 2013
2,763
9,768
Adelaide, Australia
Oh, I did just have a thought about this and it offers you an opportunity to check your shadows and highlights to see just how black or white you are, for the purpose of printing refinement. For example, with my printer I can take the blacks to about 6% before they are just black and the whites to about 92% before there is no difference to the whites. Hopefully that makes sense?

It's a crude version of what I do in Photoshop, where I have several points in the shadows and highlights I monitor in editing and before printing.

Apart from that, I can't think what they may be for.
 
Comment
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.