I was in Manchuria this winter and the daytime temperature was minus 35deg C at dawn, rising to a balmy minus 23deg C during the day. Using my Mamiya C330, I found the leaf shutter dragged in the extreme cold. The release mechanism tripped but then the open/shut of the iris was delayed by up to ten or fifteen secs. Fatal for action shots. If I took the lens off the camera and put it in my jacket I could warm it sufficiently to get perhaps a single shot before it was too cold to fire again. And fumbling about changing the lens is no fun in the cold. Anyone else with these problems? I've heard you can use a low temp lubricant, but will it work down to minus 35deg C? Peversely my motordrive Nikon F3 worked flawlessly, though I kept the batteries in my jacket as a precaution. The blind shutter does not seem to be affected by the extreme cold. I am going back in Jan, maybe with a Bronica SQ this time, and a cold weather battery pack. Am I going to have the same problems with the shutter though?