Half-Life 2: Lost Coast:
HDR stands for High Dynamic Range, and is also sometimes referred to as High Dynamic Range Imagery (HDRI) or High Dynamic Range Rendering (HDRR). The Dynamic Range is the ratio of the largest value of a signal to the lowest measurable value. Current 16-bit integer-based formats use colour component values from 0 ("black") to 1 ("white"), but don't allow for what is known as "over-range" values, for example, a whiter-than-white highlight glinting off a piece of metal.
HDR facilitates the use of colour values way outside the normal range in an effort to produce a more realistic rendering of a typical 3D scene. If you have ever driven through a dark tunnel in your car, and then emerged out the other side into blazing sunshine, temporarily blinded by the difference in light levels - that oversaturation is one example of what is possible with HDR. This technology will be used for HL2: Aftermath.
You can see that technology with Lost Coast. So I decided to post some screenshots which I took myself. The pic is on the left, and the info about the pic is on the right. Everything was set on High, in the Video options. There's 37 screenshots. Enjoy!