(High Dynamic Range photography) is taking a photo at low, medium and high exposure and blending them together to get the best results.
HDR tries to get around the limitations of traditional photography to present images in the same way as the eye sees them. When you look at a sunset, you see the sky and the beach equally as clearly.
What you’ll need is a camera that does bracketing, a computer and some HDR software.
You have two options and they’re the same on both Mac and Windows PC:
Adobe Photoshop and the Photomatix plug-in.
HDR images contain more detail in bright and dark areas than ordinary images. However, because of its large dynamic range, an HDR image does not look "correct" when displayed on your monitor. With Photomatix, you can process this HDR image for output on a printer or for display on a monitor.
To create the best HDR images, you need to take enough exposures to properly cover the dynamic range of the scene.
If your camera offers Auto-Exposure Bracketing (AEB), select the Continuous Shooting mode, make sure the camera is set to Aperture Priority, and select an exposure increment of +/-2. The camera will automatically vary the shutter speed each time the shutter button is pressed, taking several exposures spaced by two f-stops.
You may have to change the exposures manually if your camera does not bracket in steps greater than 1, or if it can only take 3 auto-bracketed frames when the dynamic range of the scene requires 5 or more.
Photomatix enables you to align images if the camera moved slightly between frames, but using a tripod is still recommended.
I found at first it was very easy to go over the top with the effects but now find that results are better with a subtle balance.
Go to the Photomatix site

Below are a few samples of HDR.

Bigbury On Sea Devon
Bigbury Devon

Plymouth Borough Prison
Plymouth Borough Prison Greenbank Former central block of Plymouth Borough Gaol. Opened in 1849 to the designs of Thomas Fuller (1823-1898) and William Bruce Gingell (1819-1899) with William Clift as building contractor.

Plymouth University Roland Levinsky Building
Plymouth University Roland Levinsky Building .

Dartmoor Pony
Dartmoor Pony.

Bodmin & Wenford Railway
Bodmin & Wenford Railway

Smeaton Tower Plymouth Hoe
Smeaton Tower Plymouth Hoe.

Acceptance Mark