One of the D90's most useful features, although somewhat overshadowed by the bells and whistles of live view and the video mode, is Active D-Lighting. This selectively adjusts the exposure of different areas of the image, helping to prevent burned-out highlights and featureless black shadows, and increasing the effective dynamic range of the camera. This feature is found on several other Nikon model, including some compacts, but on the D90 it gets five different levels as well as an automatic mode. It works extremely well, and on my test shot of an underground car park both the brightly lit exterior and the shadows under the stairs have plenty of detail.
The much talked-about video mode has its good points, but also some serious limitations. On the plus side, the video quality is extremely good. Shooting in the maximum 1280 x 720 high-definition mode at 24 frames per second the quality is comparable with a dedicated HD camcorder, and the ability to use the zoom lens is very useful. Shooting high resolution video through a top quality long telephoto lens could be very useful for wildlife filming or bird watching, with the camera mounted on a tripod, but unfortunately there is one major drawback when using it hand-held. There is no autofocus available in video mode, which means you have operate the focus ring on the lens barrel while at the same time trying to hold the camera steady and frame the shot. As I've noted, the D90 is quite heavy, and its balance when fitted with the 18-105mm lens means that taking a steady shot needs a two-handed grip, and the same is true when shooting video. This makes it almost impossible to shoot steady, in-focus shots of moving subjects.
While many people seem convinced that there must be some sort of convergence between still and video photography, and that this camera is a step down the right road, I have to say that I disagree. As with all tools that have developed and evolved over time, the form of a camera follows its function. Video and still cameras are different shapes because they have been developed to do different jobs, and the shape of an SLR camera, or indeed most compact cameras, is not particularly well suited to video shooting. Camcorders, and even more so professional-quality video cameras, are the shape they are for a reason, and to expect an SLR do the same job seems to me to be rather foolish. I'm not saying that DSLRs shouldn't have video modes, and indeed I'm sure that other manufacturers will follow Nikon's lead and nearly all of next year's models will have this ability, but I can't see it being more than a gimmick, or at best a sort of bonus extra feature. I certainly wouldn't pay extra for it.