Shootout: Sony A7R vs Sony A7 (Red Barn)
In Guide to Mirrorless is published a comparison of the 36-megapixel Sony A7R to the 24-megapixel Sony A7.
The comparison includes actual pixels from each, and also upsampled and downsampled comparisons to show both how much difference there is, and other relative image quality aspects (e.g., the oversampling and downsampling ideas).
Apertures series from f/2.8 through f/11 at HD and UltraHD sizes are also included.