In the Black II
Previously, in that same blog, I mentioned the improvements I've been seeing in the blacks levels of the new video displays that employ an automatic iris. But as good as they are beginning to look, nothing can as yet beat out a good CRT in the contrast derby.
The last time I measured the peak contrast on my three-year old Hitachi 51SWX20B HD-ready CRT projection television I obtained a result of nearly 30,000:1 (just under 30fL peak white, 0.001fL video black)!
Granted, the Hitachi's video black reading was at the lower limit of my Minolta LS-100 light meter's specified sensitivity. But even assuming an error of 2:1 in the reading, that would mean a peak contrast of 15,000:1. Or, with an error in the other direction (just as likely), 60,000:1!
But I didn't need a light meter to tell me that. If I put a full video black test pattern into the Hitachi and completely shut out any ambient room lighting, everything goes black. You can't distinguish the screen from the darkness around it until a few seconds later when your eyes adjust. Even then, you can just barely see it. This is the darkest black level I have ever seen on any consumer video display.
That Sony front projector, as you will learn from the review tomorrow, also measured spectacularly well on my projection screen with its Advanced Iris engaged—0.002fL—though with far less peak white output than the rear projection Hitachi with its smaller, high gain screen. But since I can still make out the outlines of the screen on the Sony with a video black signal, and I cannot with the Hitachi, I suspect that the Hitachi is actually producing less than 0.001fL in video black. But the Minolta meter will not measure lower than that.
There's no denying that today's fixed-pixel, digital video displays have made dramatic strides forward, outperforming CRTs in many ways. That Hitachi, for example, is nowhere near as crisp-looking on HD programming as most of the digital displays I've seen. But while matching the black level and shadow detail a great CRT display remains elusive, it should be an ongoing goal for video designers, whatever new technology they employ.