Shooting the mosaic with its ultra-fine details with (the same lens), I was struck by just how much better the Sony EVF is than the Leica VF-2 on the M240.
The extra resolution of the 36-megapixel Sony A7R means that at 14X there is more to be seen than with the 24-megapixel M240 at 10X.
But it’s about a lot more than sensor resolution: the Leica VF-2 just looks blurry by comparison to the Sony EVF regardless of what it is displaying, and its contrast is inferior. Which means that the ability to discriminate accurate focus is impaired using the Leica VF-2, in all cases.
The Leica VF-2 is 1.4 megapixels; the Sony built-in EVF is a much crisper 2.4-megapixels. With the M240 + VF-2, grout lines between the tiny tiles all but disappear; with the Sony A7R, grout lines pop into focus when the focus is perfect. Still, it’s fair to say that something around 4 megapixels would be even better.
Moreover, my extensive field work with both cameras tells me that the Leica VF-2 resolution can be a source of errors: it often leads to front-focus errors particularly with slower lenses. It just does not have adequate resolution, so one is forced to use focus peaking, which is a poor solution for optimal focus (close but no cigar).
Leica should support a high-res EVF option, even if the CPU in the M240 can only deliver 10 or 15 frames per second refresh rate. The VF-2 offering feels hugely inferior in comparison to current EVF technology, degrading the M experience.