When I change the exposure from -3 to +3, the histogram on my viewing screen doesn't change, nor the image is getting darker or lighter. It is no live view anymore. (It is after I made the photo, that I can check the exposure, in view mode.) How can I change this to live view, what am I doing wrong? Camera: E-P1, updated software 1.4, lens: Lumix 20mm, updated 1.1 Your help will be much appreciated, thanks. Frank.