My questions came from several observations from the field and PP.
On my street camera, wich has a 12MP aps sensor, if I mount a 35mm top prime, it is like the sensor is not the same and these lenses reveal
the real nature of the equipment. In fact in PP, just working with top lenses gives me more flexibility. IQ is way better, not little, but a lot better.
The overall detail is much much present, so logically, any lens that is not top class is limiting a 12MP sensor resolution power.
Parting from that simple observation, I asked myself if there is a limitation in the other side.
Are these lenses capable of rendering properly the sensor's increased resolution that we see year after year? What's the limit?
Let's take a canon 7D, 18MP. Then the last cheap entry level 550D, 18MP, same lens on both, top quality. I guess IQ will be exactly the same.
What's not clear for me is that one day, in the On line Photographer website, he did test an EP1 with Leica M lenses. To his surprise, he did
not found any increment in IQ between the "cheap" Oly lens and the top Leica M. (Can't find the link any more but it's there).
So the logical conclusion is that the MFT sensor is limiting the real power of the lens. (or maybe an even more exotic conclusion would be that the Oly lens is as good as the Leica M?!?...won't come in that terrain)
So, what's worth investing in a very expensive lens if the
sensor's size is not capable to deserve it to it's full potencial.
And on the contrary, what's worth investing in a top MFD camera if the lenses don't follow and are not capable to deserve the sensor's capability. Do they deserve well your huge resolution sensors?
When sensors will reach more resolution in the future, do you think a new lens design will be necessary?
So my conclusion (but not sure about it) is this: Bigger possible sensor with better possible lens, thinking that the lens is maybe more important than the sensor itself.