Which full-frame mirrorless camera actually delivers superior dynamic range for low‑light street photography – Sony A7R IV vs Nikon Z9?

Been grinding the night streets for weeks, pushing ISO 6400+ on both the A7R IV and the Z9. The Sony claims 15‑stop DR, Nikon boasts 14.5‑stop, but real‑world results? My A7R IV images still have that subtle highlight roll‑off, while the Z9 seems to clip sooner despite the same exposure settings. I’m also using a 35mm f/1.4 lens on both bodies, same sensor‑size crop factor, same post‑process workflow (Capture One, ADOBE Lightroom Classic).

So, which system actually gives you the edge when you’re trying to freeze a neon‑lit alley without losing detail in the shadows? And while we’re at it, any specific firmware tweaks, custom picture profiles, or base ISO tricks that actually make a measurable difference? I’m not interested in generic “buy the newest model” fluff – I want hard data, side‑by‑side comparisons, and maybe a few dissenting voices who think the Sony still wins on DR. Bring your charts, sample RAWs, or even your own night‑shoot anecdotes. Let’s cut the marketing hype and get to the gritty truth.