There looks to a one behavior I am seeing with the Sony A1 that makes it a very significant step up from the Sony A7R IV, at least for shooting at higher ISO, and possibly for long exposures (TBD). And you’re not going to see it in “lab test” numbers.
I’ve said a few times now that the A1 files just look better to me. This may be the reason.
I am being non-specific because I want to reproduce it again under better-controlled conditions before I show it. That means waiting until tomorrow afternoon for just the right late-day warm sunlight I want (and to get the darn cat hair off my black fabric background).
Anyway, an ISO 3200 frame is shown below.
UPDATE: I have confirmed exactly what I saw yesterday. But along with variable lighting (fluctuations in intensity and color due to clouds), and the unexpected ruination of some work by a the Voigtlander 65mm f/2 APO-Lanthar (the 65/2 defocusing itself) means I’ll have to finalize the comparison series tomorrow.