12-21-2016, 11:53 AM
Sorry I understand that it will not work. But maybe I wasn't clear enough. I will go step by step so you can say at which point I start to get lost 
i) when you measure the MTF with the same system that you use to test Nikon 20mm f1.8, the max value you can get is 4000.
ii) for the old setup, the max was 2320.
iii) the measured MTF with the old setup is 2200. it makes 3793 in the new setup.
iv) since the new setup is much more sensitive and precise, the new MTF will more likely be below 3793.
v) in the dx sensors, borders are much closer to the center wrt the ff sensors.
vi) MTF decreases gradually when you go from the center to the border.
vii) therefore as a general fact MTF of the borders will be lower when it is measured with ff sensor.
i) when you measure the MTF with the same system that you use to test Nikon 20mm f1.8, the max value you can get is 4000.
ii) for the old setup, the max was 2320.
iii) the measured MTF with the old setup is 2200. it makes 3793 in the new setup.
iv) since the new setup is much more sensitive and precise, the new MTF will more likely be below 3793.
v) in the dx sensors, borders are much closer to the center wrt the ff sensors.
vi) MTF decreases gradually when you go from the center to the border.
vii) therefore as a general fact MTF of the borders will be lower when it is measured with ff sensor.