Constant Contrast - Dynamic Iris
Constant Contrast is Runco's name for Runco's dynamic iris function. The dynamic iris action is very nicely smooth compared to most lower priced projectors, but there are several at least as good. This is, however, a "good" dynamic iris, in terms of being rarely very noticeable. I never found it annoying, even on the dark conversational scenes with the camera cutting back and forth between two people speaking in a fairly dark room without a lot of very bright areas. It responds rather smoothly when there are radical brightness changes between scenes. Detectable, if you are looking for it, and only on occasion, but rarely will it show up on your radar. Impressive blacks despite a rather unimpressive contrast comparison spec claimed of 10,000:1. It certainly gets those blacks on dark scenes down there with other projectors claiming 30,000:1, 50,000:1 or even higher.
As previous stated, the LS-10d projector is primarily about the DHD4 processor. The DHD adds $6000. Well, besides lots of inputs, screen triggers, and command and control devices. It would be interesting to see an LS-10i and a LS-10d side by side to see how it improves the picture. After all, you can buy a lot of switching for $6000!