HDR seems more like a gimmic because most of the time (at least from the demos I’ve seen in stores) it just looks like someone boosted the everloving shit out of the contrast and it’s always looked a little eugh.
HDR is actually pretty cool. It enables TVs to display a wider brightness range than was previously possible. Unlike just boosting contrast (which would simply make dark and light areas more extreme, with the results of whites being clipped and blacks being crushed), HDR actually displays more of everything. Here’s an example from a video game:
Standard
HDR
