I was not talking about technology advances but commercial technology advances. It is easily possible to make a 1.5 litre engine develop 1000bhp. But it is a lot cheaper to develop amd build an 8litre engine to develop 1200bhp.
Wrong methaphor for the subject.
Personally I thisnk the APS-C sensor is coming quickly to the point of commercial technology limitations - ie it becomes cheaper to move to a larger, lower tech sensor to get a bigger improvement.
For sensors the easy (read cheap) way to get more from a sensor is to increase the size - and I believe we are getting close to that point
That's simply not how chip production works. In chip production (and that applies to all kinds of chips, not just image sensors), a bigger area means exponentially higher costs. It's not that important what is actually on the chip.
The price for a chip of a certain size only significantly drops every 5 years or so when the industry is changing to larger wafer sizes. The reason why other chips get cheaper and cheaper is because they get smaller (or you can fit more complex designs into the same space).
Image sensors do not benefit from these effects since their size is fixed.
But even if overall sensor manufacturing costs would be low enough for a rebel-priced FF camera, all other components are more expensive as well: The viewfinder prism, the microlens array, the AA filter and also not to forget that wide-to-standard lenses need quite a bit more glass compared to their APS-C counterparts, thus FF camera systems will always be more expensive than ones with smaller sensors.
Computer technology is ahead of sensor development (in its timeline) - but there hardly been any significant progress in PC 'power' for the last 3 years. The push has been in multi core - ie 2 cores go faster than 1, rather the speed the single core. Even the entry PC's now have a minimum of 2 cores, midrange have 4.
That's because today's quad-core chips fit in the same die size as single-core chips did a few years ago.
So is that why they continued developing the APS-H and even demo'd a 120mps APS-H. I guess that is another myth that is not supported by facts
In my opinion:
- The 120mp APS-H sensor was just a technical exercise (so far there has been no indication that Canon is planning to put it into a product)
- The reason Canon went with APS-H on the 1D for so long was partly because it was the largest size that could imprinted in one shot, as stated in Canon's full-frame white paper
- APS-H was never a mainstream solution for Canon. It was always limited to a single camera model and (unlike APS-C) they never produced a single lens targeted at that crop-factor.