Here's a nice long exposure shot with the Singh Ray Color Combo and Singh Ray 3 stop Reverse GND handheld.
Stunning, the tones and micro contrast are amazing.
I can see how a caffeine induced twitch might have helped you with your "feathering". 
Would you say the color combo effect cannot be replicated in post, or is it more of a convenience slash getting it right in the camera kind of thing?






