Valve's High Dynamic Range Explored

Image Comparison

For those used to the look of Half life 2 and Counterstrike: Source, the new HDR effects in Day of Defeat probably won't blow your socks off. The enhancements are subtle, but you can definitely tell that they are there. Most noticeable is the auto exposure effect, which simulates the way that the eye can be blinded slightly by stepping into the sun from a dark area. While some might complain that this is annoying, it seems to us that annoying or not, it adds another dimension to the gameplay. In other words, in a real battle, the sun in your eyes will affect your aim, thus adding to the realism of the game. The bloom effect is noticeable as well, and it is very effective at making light in the game seem brighter than it really is.

Below are some images that compare the different modes. The top-most image is with no HDR enabled, the middle image is with bloom only enabled, and the bottom is full HDR enabled.

Click to enlarge.

Click to enlarge.

Click to enlarge.

At a glance, it's easy to tell that the image with full HDR enabled is brighter than the one with no HDR enabled, but the differences between the images are subtle. Pay special attention to the glare of the sun on the rifle, as this gives you a sense of the different levels of lighting. Notice how in the middle image (with bloom only enabled), the lighter colors in the distance on the buildings and sand are much brighter and create more contrast to the scene. And with the bottom-most image (full HDR enabled), you can see how the combination of the bloom and auto-exposure brighten the scene even more. This may seem very bright, but keep in mind that this is one of the widest spaces in any of the four maps. The game smoothly brightens or darkens the screen depending on where you are in the map, and the highest contrast ratios are observed when looking out of a dark area into a bright one (or vice versa).