EX1 - Fine tuning AUTO WB

Note: This message may be useful to people who use jpg output, I am not sure if it is relevant to raw users.

It has been noted in past threads that when using AUTO WB that skies often have a greenish tint, instead of the correct pure blue appearance that we see with our eyes. This is particularly a nuisence in the morning, and not so much of a problem when shooting in afternoon sun.

I have been searching for the best solution to this for a while, even trying reduced contrast which I have documented in old threads on this forum.

The first problem that is struck is that you cannot trim AUTO WB, but you can trim Daylight WB, so I started testing outdoors by trimming Daylight until I got faithful sky colour. This can be achieved by using Y=-1, X=0 on the graphical adjustment scale. The problem with this solution is that as soon as you come indoors or go into unnatural light the WB is all wrong.

This led me to believe that for a WB that works anywhere then AUTO must be used. So the question is how to adjust the AUTO WB until it is exact. I found I could do this by going to Photo Style Selector, RGB, and adjusting this and then leaving it as a permanent default. I found the correct adjustment to be R=0, G=-1, B=0.

While this method produced excellent WB in all conditions, it has a major drawback, which is that it causes Smart Filter, Image Adjust and Smart Range to be grayed out. I only use Smart Range and only occasionally, so I can live with the loss, and the equivalent can be obtained more easily by Using the SCN position on the top dial set to a default of Backlit. So no big losses.

Here is an example taken with the setting on a very sunny day.