There is a difference in sharpness between the formats, which one can predict by looking at any lens' MTF graph. The way this is traditionally reported, lpmm at a given contrast level, sometimes leads to the mistaken impression of a difference in resolution when it really is not. The details are there, the detail contrast is just not as high OOC. lpmm @ MTF50 on FF might equal lpmm @ MTF40 on crop (for example).
At ISOs where sharpening will not negatively impact noise, it's trivial to equalize sharpness, and doing so will generate similar numbers (lpmm for a given contrast) using the same testing software.
- at dxo mark, the great sony 55 CZ lens on A7R or d810 scores 29 MPix. Put it on the A6000 and note it drops to 15 MPix. Yikes - huge loss in resolving line pairs
Again, this is snake oil nonsense. The A6000 is a 24 MP camera, the A7R is a 36 MP camera, and there's no such thing as a lens which causes them to be 29 or 15 MP cameras.
7d or 7d2? SL1 is better than 7d for resolution because Canon has tweaked the 18 mpxl sensor over time.
I doubt there's any human observable difference between Canon's 18 MP sensors in terms of absolute resolution (lpmm) at lower ISOs. I certainly have not noticed this with the original 7D and M. There's possibly a difference in sharpness (AA filter), though that has not stood out to me either. The 18 MP sensors did improve in terms of high ISO performance which can lead to less aggressive NR and more retained detail.
you can put a sony 55 CZ on it, stop down, and get 29 MPix - which blows away anything you can put on the A6000
One of the more annoying aspects of DxO's snake oil use of MPix is that it makes people think there are huge differences where there are not. A debate with a friend resulted in us making 36" prints from RAW files produced with the A7R, A7, 5D3, and 70D. He predicted differences would be obvious between all four, and that the A7 (for example) would "blow away" the 70D. I predicted only the A7R would stand out. We were both surprised. Small differences were human observable in the most challenging areas of the A7R print, but otherwise there was nothing to pick the four prints apart. I will note that this was not SOOC, but we applied processing we would to any image intended for exhibition.
MF digital or stitching...with crop or FF...seems to be required to make a real jump to the human eye in print, and even then the gain is best seen in larger print sizes.