Been doing a fair bit of reading lately regarding accurate WB. The general consensus seems to be that Auto WB just not up to to. The solution seems to be to use an Expodisc, white/grey cards or any one of a number of other gizmos to take a WB reading of the ambient light. This is OK if the ambient light is going to remain constant for some time, if however it is likely to change then this is a terribly tedious way to achieve a correct WB reading. So, it's Auto WB or a tedious selective WB reading. Anyone got a really quick way of taking a WB reading? The E-M1 goes part way with it's One Touch WB, manual page 59, but the value still has to be registered either 1 to 4. Why is it necessary to register as default, if not registered the WB reading taken could simple overwrite the previous reading or registered if required. Why with modern technology can the camera not determine the correct ambient WB at the instant before taking the picture and apply that to the scene?