Yup, which is why I'm dubious that the 1Dx will somehow be quite as good as it's being made out to be or that upgrades to the 5D or 7D will somehow double (or substantially increase) the MP while retaining or improving noise and DR.
Unless someone makes a chip with double the Quantum Efficiency of the sensor I don't see any behemoth improvement that suddenly makes everything else look like a POS.
Check out some of the graphs in here, particularly figure 2. We've dicked around with more or less pixels, slightly better QE, slightly better micro-lenses, different pixel gaps, improved read noise, better filters etc.., but the fundamentals have stayed more or less the same. We need a completely new type of sensor next.
http://www.clarkvision.com …rmance.summary/index.html
Well, my take on things is that yes, there is an advantage to having the full frame sensors with the larger pixel wells, a better signal-to-noise ratio, and then the advances of technology have helped make for more efficienat light collection, which benefits not just crop sensors but full frame as well.
Now I do expect the 1DX to be game-changing for Canon because backing off on the megapixels means significantly larger pixel wells over the 5D2 and especially the crops. The word is that the 1DX will have a two stop improvement over the 1D Mk IV which, though not earth-shaking is still a very significant plus.
In my little "project" you can see some actual improvement just going from the 30D and 5D to the 1D3, the advantage of improving technology, since the pixel density of the 1D3 is not "better" than the 5D.
(random thoughts) Apologies!
