Well, I have all three formats... 35mm old manual Nikons, brought down two backs, one with velvia 50 in it the other portra. Then a new, for me RB67, MF... with two backs.. Provia 100, and TrX 400, and last not least, a '46', (orphan) 3x4 Anniversary Speed, that I used that night, with Efke 100 in it.

I love the three formats, the 35mm with a macro lens on it for flowers, (also have standard 50mm, and 80-200) the MF which is becoming a mainstay, for landscapes and anything else, and the Speed for B&W.

Ain't life grand.. ;-)
All manual, the Nikons backs do have good meters in them, the rest get an 'ole but goody, Weston Ranger 9 light meter, that I modified to take modern batteries, for a reading when necessary

So what's a little darkness, or light within it, that didn't get exposed correctly. Sounds like photography. ;-)
Will do it again.

Soooooooo ya mentioned earlier in this thread
"I've been wanting to experiment with similar things."
Your close to Bandelier, that faces north doesn't it? Ha a new moon will be rising soon to but some shadows on the ruins, and with the sky above... hmmm...

You just made me an idea, maybe will make that our first stop. ;-)