My wife and I went to a tango event in town. X-Pro 1 with 35mm F1.4, shot with manual focus (pre-focused on specific spots on the dance floor), 1/60 sec, F4, Auto ISO between 5000 and 6400. Silver Efex Pro 2 Antique Plate preset. Great test of X-Pro's lowlight capture; OVF was really helpful in anticipating action and framing. Fairly extreme cropping on the original JPGs, with still a lot of good detail.