There is this method to get MTF directly from bars without the CTF / MTF hassle:

https://www.osapublishing.org/ao/abstract.cfm?uri=ao-34-34-8050

Interesting. Unfortunately is been some years since I had easy access to journals.

The following sequence of points, sampled at Nyquist and derived from a maximal length gf extension field, has the interesting property that it produces 7, nicely spaced frequencies each of the same amplitude. And they have the maximum RMS magnitude relative to peak to peak magnitude. The maximum freq. component is at 7/15 of sample freq. The individual components are 1/15, 2/15, ... 7/15 excluding the DC, fixed offset.

1 1 0 0 0 1 0 0 1 1 0 1 0 1 1 .... repeated

What I like about it is that MTF computations are straightforward and not sensitive to aliasing at all. It does require a good, linear printer and is part of the reason I'm fairly picky about RelCol profile accuracy.

I used the 7 points of MTF from this in a formula to determine imager chip/lens registration flatness for QA purposes in a camera company I was once involved with.