A specially modified 42-megapixel Sony A7R II (conversion by KolariVision) is compared to the 24-megapixel Leica M Typ 240 using Leica’s best M lens, the Leica 50mm f/2 APO-Summicron-M ASPH in order to explore the resolution gains on the 42-megapixel sensor of the modified A7R II.
The A7R II sensor has 75% more pixels, but pixels should not be confused with resolution. The difference in resolving power is 5976 vs 7952 = 1.3X. And that is the best case, assuming the lens is perfect. Resolution gains should be visible but not dramatic, and such gains also demand optimal focus and execution.
The point of interest is just how much extra resolution can be obtained from the 42-megapixel Sony sensor, given that the Kolarivision mod is much improved over a stock Sony A7R II when using Leica M lenses, as shown with 18/28/50mm comparisons.
This is a definitive and thorough examination of just what the potential gains really are. That said, it is incomplete in that field results could turn up with other issues. The analysis shows the best possible results that one could expect.
The answer is presented two ways from f/2 through f/8:
- The A7R II Kolarivision mod downsampled to M240 resolution.
- The M240 resolution and A7R II Kolarivision mod resampled to a common resolution.
This dual analysis gives the fairest view of what the gains can be. Note well that the results with the Leica 50/2 APO are likely the best possible case in favor of the Kolarivision mod; wider angle lenses may fare less well since they do not reach the same level of performance in the outer zones (even at f/8) and/or have much more field curvature (for faster designs).