Normally I prefer to use letter stamps at a 5m distance for testing purposes. Because the patterns repeat over and over, center sharpness and corner sharpness is easier to compare.
At the perforation holes it is easy to see CA. Also distortion is easy to see.
There is still some loss due to shutter shock.
With a sony a57 with electronic first curtain enabled there is no shutter shock at all and it is so sharp, that the printing dots can be seen. Also I see the dots in the focus magnifier of the OM-D as preview, but not in the resulting image.