Can anyone give their opinion of the sharpest F stop for the following lenses


(assume all other factors are constant)


(all canon lenses)


70-200 f2.8 I L


17- 40 f4 L


24-70 f 2.8 L


50 f 1.4


135 f 2 L


In general my recommendation has been two stops above the widest aperature and kess than f 11


Can anyone be more exact