Originally Posted by Brad Gosse

It's actually what you ARE seeing

Very rarely can a single shot capture all the nuances that the human eye can see. The reflection in the windows, the wood grain on the ceiling etc. Normally in order to focus and properly light one subject. the background items tend to be too dark or too bright. This method takes 3 shots at various exposures and pulls the most detail from each shot to make the hybrid.

Make sense?