As a Canon shooter I have only a marginal interest in what Sony is doing, but the use of an electronic viewfinder and the pellicle mirror is a genuinely interesting development. The advantages that this system brings are plain enough, but my curiosity centres around what compromises have been made to achieve them. It would therefore have been most instructive to have compared the 580 and its non DSLR stablemate to see what, if any, deterioration in IQ and light transmission the new system involves. Putting the two cameras side by side, does the fixed mirror cause any significant light fall off, i.e. do you need to use a wider aperture or longer exposure? Does the insertion of another pair of refractive surfaces damage the image quality? If the answer is that there is no significant deterioration then this would, perhaps, signal the end of DSLRs as we currently know them. Come on AP, let's do some meaningful tests!