I had a studio shoot this last weekend with the lovely Katey. I took the time to test some of my white balance tools.
Sunlight, age and general use, dirt, oil from our hands all slowly impact on the accuracy of white balance tools.
I have three of various ages.
An X-Rite Colour checker is my oldest and I use it for creating profiles as well for colour critical work.
My little WhiteBal card, and a pop-up grey/white balance card.
My pop up colour confidence grey/white balance card I tend to use the most, it also gets used on location so gets dirty, and has been rained on.
So I decided to, in a single shot capture all three cards. Then cloned it three times and used the white balance picker in Lightroom to compare.
As you can see the white balance card and colour checker despite there age are still close together. The pop up card is showing much warmer.
I really need to repeat the experiment under more controlled lighting conditions but it was interesting.