Last Friday I shot some portraits with Mike Brown. I really love the look the late night gave it. even though I'm using my 550D which isn't great for noise, the images turned out pretty good. I used a flash and a phone light to light a few, but most were just lit by lights we found. It helped having F2.8 on my 100mm as it was a lot brighter than an F4 zoom. I also used a 50mm F1.8 for a few shots.
I really loved the phone shots, but the screen wasn't bright enough, so I used my phone with the torch on facing up to uplight like a screen would. I was a nice work around to see the light cast by a phone, with out upping the ISO and making the lights blown out and the image grainy.
Hope you enjoy!