[fletch]

The human brain is the worlds best HDR processing software. The eye is constantly scanning the scene and recording different parts of it all at once. The image that is finally presented to the concious part of you brain is actually a mish mash of all the different images. Its not just exposure blending either, the brain is constantly adjusting for focus and colour as well.

The key to the eye is it processor (the brain) Its actually a pretty crappy camera.

Since the brain can't perform this trick with photos due to the limitations with prints and screens HDR tries to do the work for it, prior to printing or display. It is taking the 'best' bits from the multiple exposures to replicate what the brain would have done if it were stood their.