Logitech’s MX and Darkfield
Unfortunately, I wasn’t able to test out the Logitech Performance Mouse MX ($100), but based on my prior experience with the form and comfort of the MX line, I’m guessing this new MX is the ergonomic mouse to beat in today’s consumer market. Simply put, I’ve never met a more comfortable mouse. For my hand, its weight and contour for everyday use is unbeatable. Add in the Darkfield technology and it might as well be perfect.
What’s Darkfield? It’s as if Logitech said to Microsoft, “BlueTrack, SchmooTrack. Watch this!” When you read the literature for BlueTrack, the fine print gives you the same news we’ve known about optical and laser mice for years: This mouse works on everything except glass and highly reflective surfaces. Darkfield technology has no problem with such surfaces. In fact, it was made specifically to work on them.
Dark-field illumination is commonly used with scientific microscopes for situations in which the traditional method of shining a light up from below, through a glass slide, and into the magnifying optics can’t yield a decent image because the light overpowers the subject. Dark-field illumination blocks out the direct light and only allows angled light to strike the lens. If there’s nothing on the glass slide, then the scene appears totally dark. Otherwise, light scattered by any objects on the glass gets passed on to the lens.
Logitech’s Darkfield technology uses two lasers to illuminate a surface beneath the mouse at an angle. But unlike a traditional mouse that essentially takes a series of pictures of a surface and examines the pixel changes between the images to determine distance and direction, Logitech is actually taking pictures of dust and other residual matter on top of the surface. When the laser hits glass, most of the light is lost through the transparent material, but any imperfections on the surface of that glass will reflect light back to the sensor and register as a white object on a black background. Darkfield won’t work on a perfectly smooth surface, but in environments outside of science labs, there’s no such thing as a perfectly smooth surface, especially if that environment has kids.
No, Darkfield isn’t central to an ergonomics discussion, but it is pretty cool, and it touches on the rationale of spending less time in contact with your mouse if you have better control over its movement. Given that so many modern environments have glass or highly reflective surfaces (glass tables, countertops, etc.), this technology would seem to be at least somewhat valuable in any ergonomic mouse.