Re: lens resolution

For theoretical comparison, you're looking at "perfect case" scenarios concerning how many line pairs per millimeter these camera sensors can resolve (real world results may be considerably lower because of the use of low-pass optical filters and Bayer pattern pixel sampling).

For this you're looking at pixel pitch (5.4 for the Epic as far as I could find, and 4.3 for the 7D) and airy disc size (controlled by the lens aperture). Reading charts widely available online, the theoretical maximum resolution at 50% MTF is ~90 lp/mm for the Epic and 116 lp/mm for the 7D.

Lenses, depending on their aperture size (and airy disc size) will resolve varying amounts of detail. The wider the aperture, the more possible resolution although the lens has to fight distortion and optical aberrations.

The 7D has a diffraction limit at f/6.9 (if you took a "perfect lens") which means the sensor will out-resolve the lens at any aperture that is smaller.

The Epic, on the other hand has a diffraction limit around f/16. A perfect lens is out-resolving the Epic sensor for much of the throw of its iris.

It might mean that Canon is trading off some resolution performance for better overall edge performance, distortion control, better resolution across color wavelengths and so forth... or it could be very close, if not match the performance of their L lenses. There aren't any official MTF readings, test chart samples, lp/mm slit test readings for these lenses.