Just to let you know on my 24" iMac I have the brightness turned down to the lowest level.
I use the Spyder 4 PRO with a few different lighting condition profiles.
Pictures printed on a Canon PRO-10 Printer with Canon Luster paper with Canon Luster profile.
Pictures are spot on.
On a MacBook Pro, I have my monitor on the Middle position. Why the middle? Because the MacBook Pro will go black all the way down. Different monitors.

