Here you are

MTF at the center of the field is naturally high, at the edge of field will drop off a lot that is the difficulty.

For this lens with diffraction limited performance, the MTF should be 0.99 at 10lines/mm, 0.98 at 20line/mm and 0.95at 40line/mm all over the field

This lens has MTF 0.69 at the center and 0.49 at the edge for 20L/mm

This lens has MTF 0.42 at the center and 0.19 at the edge for 40L/mm

It's a very good lcommerical ens.