Interesting that the photos supplied by the OP are leading people to conclude the Sigma fp has effectively the same detail or resolution capability as the sdQH.
It doesn’t. Well, probably not. (Because DPR never tested the fp, I substituted Sony A7 III for fp in the following test image, which DPR say has a weak AA filter compared to none for the fp. But a weak AA filter has *very* little effect on resolution compared to the blatant difference we see below.)
I took the DPR test image at ISO 100 for A7III and sdQH (X3F) and processed in the same software (Affinity Photo), roughly matched brightness and WB, and resized to same size (54 MP). Let’s look at a small area of the test image at 200%.
The difference is stark. Is it all in the Sony’s weak AA filter? I very much doubt it.
cheers
[Edit: apparently the Panasonic S5 has a 24 MP full frame sensor and has no AA filter, just like the Sigma fp, so here is its equivalent image. Confirms my point.]