<p>The whole point of having a mirrorless system is so that you can design lenses that aren't a retro-focus design. They should be more like a normal lens. You would still need to increase the light circle, but that should be cheaper than a retro-focus lens.<br> a 35 ƒ1.4 for a mirrorless camera ought to be *cheaper* and better than the same lens for an SLR.</p>