Olympus OM-D EM5 flash not good?
light. With the flash the pics were very dim or the foreground bright and subjects behind dim.
Light fall-off follows an inverse relationship to distance, so yeah, if your flash is your only source of light for the exposure, the background will always be much more darker than the foreground, assuming the background is double the distance from the camera that your foreground subject is. If you are using on-camera flash and no remote flash, then the only way to easily work around that is to use a long shutter speed so you can use ambient light to bring up the background. In other words, use an ISO/aperture/shutter speed that will get the background to 1 or 1.5 stops under-exposed, and use the flash to properly expose the foreground.