A friend of mine who is very interested in remote reality (aka telepresence) already has a HMZ-T1, with which he is quite satisfied, but we were both eager to compare it with my new ST1080. As it turns out, the two devices have different weaknesses, some of which were surprising.
First, the field of view. You’ve seen it mentioned, something along 40° vs 45°, but that doesn’t really convey the difference. Trigonometry tells us it would be a linear difference of nearly 14% in apparent screen size. Marketing numbers, 150″ vs 100″ screens (note how that’s way off from the prior claim). But the reality of it is, the HMZ-T1 has a notably larger field of view – at the apparent cost of a very small sweet spot. You have to adjust the set precisely to get even part of the image sharp, and with the mechanism that locks the optics in steps, at least I cannot get the whole image sharp at once. With the ST1080, this problem nearly only occurs in the vertical placement, and is much milder (although I sometimes get an impression it’s dim instead of out of focus). Anyhow, for a repeatable measurement I took my compact camera and put it against the display unit, and snapped one picture from the ST1080 and one from the HMZ-T1.
As for color, the HMZ-T1 defaults to a more saturated and warmer rendition which it calls natural. Lacking better references, I can’t really disagree with it, but I can say the colors on the ST1080 are usable (although contrast suffers a lot in the sides for dark images). The camera doesn’t render colors from the ST1080 very well since it uses strobed colors, so the metering and exposure both get a rather random sample.
When it comes to signal sources, ostensibly the two devices accept much the same inputs except that the ST1080 extends its 1080p stereo modes with a top-and-bottom full resolution 30Hz mode. In practice, when I tried to make a response test signal in 1080p60, it turns out the HMZ-T1 completely refused to acknowledge any video signal from my work laptop (a Dell E5520 running Xorg with a core i7, Intel graphics). We therefore resorted to video from a camera for reaction speed testing.
This left us with an input that somewhat favored the ST1080 – 1920x1080i at 50 fields per second (25 full frames per second). We didn’t expect it to be a huge difference, but it was. The ST1080 produced no discernible delay in audio, at all. For video, we know the delay is at least a field time (20ms), but did not notice a delay – consistent with the common claim that we start to notice things above about 40ms. The entire resolution was obviously present, as we could see the jagged interlacing artifacts on objects in motion. The HMZ-T1, with its much more advanced video processing including color conversion, image scaling, apparently deinterlacing and a most definite audio delay to keep it in synch with the video, surprised us with a video delay of 90ms more than the ST1080. It might have a gaming mode buried somewhere in its settings, but more than four field times of delay is really uncalled for and was particularly surprising as closer high speed filming had shown the OLED displays do scan like the video signal, unlike the ST1080 which does full-frame updates. This measurement was done by connecting a camera to an HDMI splitter and flashing an LED light on and off into the lens, while filming the two displays using a high speed camera.