How it Was
Previous Spyder models have utilized a contact design, where the optical system was in direct contact with the screen. Light was columnated by a baffle, evened out with a diffusor, then redirected to a large series of filtered sensors for measuring. This system was optimized over the years by adding a larger aperture, more stable filters, and other improvements; but the overall concept remained similar.
The honeycomb structure of the Spyder5 sensor minimized the influence of scattered light. Disadvantage: The Spyder5 had to lie flat on the display surface and thus required accurate handling.
SpyderX is a complete break with that past. It uses newer, more sensitive sensors, a different color sensing method, but most importantly, it is lens-based. A large optical lens is mounted a distance back from the surface, surrounded by a stepped lens ring to reduce stray light at steep angles. The result looks much like a camera lens.
There are a number of advantages to this lens-based solution. The first is that it allows much more light to enter the optical engine, allowing more accurate measurements, especially at low light levels. And by being non-contact, SpyderX is much less sensitive to being in direct contact to the screen and at an exact angle, so perfect placement of the device is less critical. But the most interesting advantage to this new system is in its relationship to the human eye.
The Big Advantage
Device measurements are useful, but they tend to diverge from human vision, and result in mismatches to how the eye sees. This means that a device that functions more similarly to the human eye will produce less variation from what the eye sees. The result is that calibrating side-by-side displays of different types with SpyderX produces a better visual match than with previous Spyders, reducing or eliminating the need for visual tuning.
The Projector Advantage
The other place where SpyderX stands out is in projector calibration. Using SpyderX Elite to calibrate side-by-side projectors offers improved results, since the lens-based system is superior for viewing the light reflected from projection screens, compared to earlier designs, which were best off in direct contact; something that is not possible with a projection screen.