I have to be very careful how I report this information, so here we go...
Somewhere, at some point of time, someone that works for an unidentified company talked about:
- the bulk of the camera body, especially the vertical grip. The remark was that a certain company had considered a square sensor, so that the user would not need to rotate the body. Shots could be processed later to result in vertical or horizontal final images.
- the fact that a pixel density and efficiency level would be reached in a roughly 6x4.5 sized chip of near 100 MP. When you look at some of the smaller pixel sized cameras, and how they perform, the capability is already there, though perhaps the failure rate has kept them off the market. Anyway, if you scale a roughly 100 MP 6x4.5 chip to nearer 36mm square, then somewhere in the realm of 40MP seems about the upper practical limit.
- MX may just mean Multi Format