How to use Minolta color meter
You first turn on the meter and check to make sure that the meter is set to the Color balance (film or digital white balance) you are using. Here the meter is set for Daylight (D). If you were using tungsten balanced film /digital you set the meter to that (B). ‘A’ is for the old 3400K Kodak films.
You push the film button to make sure it reads 5500K or the Kelvin temperature you plan to shoot in.
You next push the side button to take a reading of the ambient light color temperature where your subject will be. Here the display reads 4000K.
You next push the LB Button (Light Balance). It reads -67.