I just said sensor size is irrelevant. Take a Sony A900 and a Nex 7. Absolutely the same. I think this is a wonderful era. I am simply going to wait for a cheaper APS 36MP camera. I think 35mm sensors are a historical dead end. APS-C is where it is going to be.
I guess you are just trying to be provocative. Right?
Surely we all know by now that the smaller sensor can only equal the image quality of the larger sensor if the pixels of the smaller sensor are at a later or more advanced stage of development, as is the case in the NEX 7 compared with the A900.
Despite the pixel pitch of the NEX-7 being smaller than that of the A900, its pixels seem to have a significantly higher DR at base ISO, and approximately the same tonal range and color sensitivity as the A900 pixel. The SNR of the A900 pixel at 18% grey is
slightly better, but not by a degree which is significant, so one would expect over all image quality from both sensors to be about the same, with the DR advantage to the NEX-7. One would also expect resolution to be about the same because both sensors have the same number of pixels.
In the case of the smaller-sensored D7000 compared with the full-frame D800, the image quality differences are entirely due to differences in sensor size because pixel quality and pixel size are the same in both cameras.
What do we find? According to DXOMark, SNR at 18% grey is over one stop better in the larger sensor, DR is about 1/2 a stop better, and Color Sensitivity is 1.8 bits better (a difference of 1 bit or greater being significant). Over all resolution (ie, LW/PH) is also better due to the larger sensor being able to accommodate more pixels of the same quality.
If Nikon were to produces an MF sensor about the same size as the IQ180, consisting of D7000 pixels, it would be a 90mp sensor, would have more than another stop better SNR than the D800, another 1/2 a stop better DR, another 1.8 bits or even 2 bits better color sensitivity, and better resolution resulting from its higher pixel count.
All these improvements would be entirely due to the increase in sensor size.
Also, another improvement to look forward to, is a 60mp full-frame sensor from Sony comprised of NEX-7 pixels. Such a camera would also have a 1/2 stop better DR than the NEX-7 and correspondingly better SNR, Color Sensitivity and resolution, due to the increase in sensor size.