<p>Hey David and Robin,</p>
<p>Sorry to reopen an old thread (wound?) but I thought it would be nice to point out that you're both right, just under different assumptions. Bob once wrote a seminal piece on this topic, and it lives right here on photo.net: <a href="/learn/optics/dofdigital/">Depth of Field and the Small-Sensor Digital Cameras</a></p>
<p>I came to this thread because I have been getting to know the Sony A7s, coming from a 6D and 5D mkIII. I really like the Sony's in-camera crop mode for the compositional reasons that OP Aaron and Marcus point out. Although many Canon EF-S lenses are a danger to the mirror on full frame bodies, there are a few that aren't, and having this crop in Live View would remove a lot of distraction in this setup.</p>
<p>Arguably you can still tear into me for using those lenses on nice bodies.</p>
