To everyone cruising through, just wondering if they should use a 5D over a Red for their next night exterior:
The MX sensor has pleasing grain, good color reproduction and low light performance similar to an unadjusted human eye. No blocking. Noise reduction and a subtle colorist can pull incredible information from shadows, truly way more than any realistic scene needs. Work in RedLogFilm and RedColor2.
The 5D and other DSLRs excel in low light stills. Their image processors and codecs are terrible. If you have an exposure at a sub-800 ISO, they can look good--in the right light, without too much motion, where the color cast and softness work for the scene. A Nikon in the right hands is better.
Tungsten light produces more noise on both systems. Sodium vapor and metal hallide (street) lights wreck havoc on 5D codecs, ridiculous shutter speed sometimes fixes this but often not. Supplementing these lights with homemade fixtures, creative DC solutions, or just a little eyelight will work wonders for any guerilla scene.
Stills pulled from motion reveal little about moving grain and compression. Test your location and have a look on your final screen--laptop, TV or projection.