Many other HDR photographers compare on their blogs 0EV photo with tone mapped one. This is what I decided to do for the first time. Just put your mouse pointer over the above image to see how the original 0EV photo looks. Note how much detail was restored in the shadows.

EXIF data:
Camera: Canon 50D
Lens: Canon 10-22 f/3.5-4.5 USM
Focal length: 22 mm
Aperture: f/9.0
Exposure time: 1/1250 s (for “normal” exposure)
ISO: 250
Number of exposures: 3
E.V. Step: 2.0 EV
Flash used: no
Tripod: no
Filters: no
Software: Photomatix Pro 4.2.3, Lightroom 4.1, Photoshop CS5