Double rainbow last night following a rain storm from our balcony in Bridgeport, Connecticut. Too bad it wasn't over a lake or mountain instead. This was with my R5 and 15-35 lens. I don't recall the exact settings but it was pretty open, maybe f3.5, 1/60s and ISO 800 because I was hand holding and had very little time before it vanished.
Wow, that's a fantastic rainbow and sky!!!! Yes, too bad it wasn't over a beautiful landscape or amazing wildlife. Maybe next time!