R.G. wrote:
With a crop sensor camera, everything gets proportionately smaller, including the aperture. That applies to APS-C, m4/3, 1" sensor cameras and so on. It's generally accepted that with full frame cameras the onset of diffraction becoming noticeable happens at around f/11. With APS-C sensor cameras it's f/8 and with m4/3 cameras it's f/5.6.
The aperture does not get smaller based on the sensor size. The OP is using the same 180 mm macro. The approximate diameter of the aperture at f8 is 180/8 of 22.5 mm and at f/32 5.625 mm. The difference is that the diffraction is more noticeable on so called cropped sensors because the image is enlarged more to have the same size view or print.