This test and "riddle" is really interesting. All four pairs of shots are taken side-by-side near the same time with the same lens with "identical" in-camera setting and Lightroom converted with the same parameters from RAW..
http://forum.xitek.com/showthread.php?threadid=808611
(in Simplified Chinese, Google English Translation Here)
The two Pentax DSLRs under test and comparison are the K-m and the K-x, which uses a 10MP CCD and a 12MP CMOS imager respectively. There are four pairs of shots, downsized and also provided with a cropped pair for each set. The order for using the cameras would not be the same for all the four sets.
How to measurbate and play the game, then? First, you should (be able to) spot the difference(s), if any. Next, you need to judge which pictures are better (if you think so). Finally, you need to decide which picture is produced by which camera per picture set! :-o :-D
Go inspect and see if you could spot the difference(s) and see if you will be correct or not! Your take now!
The answer can be found at the Post #76 down here. But in order not to spoil the fun, you are much encouraged to try your best to see and judge before reading the answer! :-)
Read Also:-
Summary Matrix for Equipment Tests and Reviews (Not further updated anymore! :-()