I have been using dslrs (500d and my 4 month old 70D) for three years now and have not attempted to use the WB Shift of my cameras on my wedding shoots or alike which involves professional fees. I tried to explore it sometimes but I am not confident in using it especially when a contract is at stake. The reason is I am confused of its purpose, questions like WHERE, WHEN and HOW to use it. I do not know how mireds (stated at the manual) should be dealt. But I do have an idea of its purpose, its correcting white balance right? Its just that I am ignorant on this chart. Hope you can share your insights guys, it wiil definitely improve my photography, I know. Thanks in advance guys.