MTF data for the new d.Fine HR-M 2.8/80 lens, this is the 0.2x version.
Source for the MTF data is the d.fine HR-M 0.2x PDF:
https://www.qioptiq-shop.com/out/Graphics/en/00132903_0.pdf
Below are two HR lenses compared, the HR Digaron-S lens (same optics as the inspec.x L HR 4/100) on the left side vs d.fine HR-M 2.8/80 on the other. Both lenses are closed down one stop, 5.6 for the HR Digaron-S and 4.0 for the d.fine HR-M.
The biggest difference between these two are across the frame consistency, the HR Digaron-S is sharper in the center but the HR-M lens is more consistent over the entire field. The HR-M lens curve is flat with little drop off in sharpness, the HR Digaron-S has a sharp central zone but a gradual drop off.
What’s the difference in image quality between a HR (high-resolution) lens and a normal high-end enlarger lens?
The difference is larger than I expected. The d.fine lens is made for a modern large sensor with a fine pixel pitch of 3.5µm. The APO-Rodagon-N has a larger image circle but is designed for much larger 7 µm pixels.