People seem to be having a hard time swallowing the idea that Nikon could do well if their upcoming mirrorless camera only packs a 2.7x crop sensor, but Thom Hogan argues that there’s a logical “hole” in the market that Nikon could be the first to fill:
So how much change does it take to make a real difference that gets noticed? The number 1.4 is meaningful in photography in so many ways. Turns out, that something around that number makes a lot of sense for capture size change, too. Each 1.4x change doubles the area of light captured. Hmm, that sounds an awful like a “stop.” [...] So if we were to make cameras about a stop apart, what would we get: a progression close to MF, FX, DX, m4/3, and whatever Nikon calls their 2.7x product.
[...] all this discussion that a 2.7x size choice is irrational is incorrect, IMHO. Having three very different choices with clearly different and increasing performance at each size is on its face a rational decision. If Nikon can deliver a stop+ better performance than the best compact camera but keep the overall size close, that represents a gain to photographers.
Though there does appear to be a “hole” in the sensor size progression of existing cameras in the market, whether anyone actually wants a 2.7x sensor remains to be seen — especially as MFT cameras get smaller and smaller.