I am out in cold weather with my Canon gear every week-end all winter here in Southern Alberta, and temperatures down to -30 Celsius is not a problem for the gear itself. I find that after 2 hours out in -30 Celsius temperatures, you may have to change out your batteries for a warm set that I carry in a inner pocket near my body. The battery voltage drops in the cold temperatures, much like the batteries in our cars under similar temperatures. The batteries that you remove from your camera will recover and may be used again once they are warmed in a inner pocket. In extreme cold (-40 C), I have used chemical hand warmers (available at sporting good stores) in a pocket of my parka to keep batteries warm. With vehicles, a battery warmer is utilized that is plugged in along with the engine block heater over-night. I had more problems with my film cameras years ago than I do with my DSLR's today when out in the cold. When exiting a warm vehicle at -30 Celsius, allow your cameras to climatize (condensation on the glass to clear) and then your good to go. Do not try to place your camera in your jacket near your body, as this will cause condensation problems. I find that my cameras will function in the cold as long as I want to remain out and about. Again, extra batteries is all thats required.
...the cold fingers problem, I found out a long time ago that my fingers were a much bigger problem to keep functioning than my cameras.
All things being equal (fabrics, thickness, and insulation), mittens are warmer than gloves. Mitts trap body heat by keeping your fingers together and reducing evaporative heat loss. In frigid temperatures, I use a layered mitt system. At one time or another I used mitts with a complete gortex waterproof outer shell. However, because of the stiffness of a complete gortex outer shell, I now use outer mitts with cuffs that have a combination of gortex and goat leather palms that allows me to hold my cameras more sucurely. I also wear mitts with a removable inner layer, as layers dry faster than one heavily insulated piece, and let you swap out wet layers. However, gloves offer better grip and dexterity for using cameras. Therefore, I use a thin (very thin) pair of fleece gloves inside of my mitts. If it is extremelly cold, I will keep my mitts on untill I need the extra dexterity. At that point I drop my mitts which are lanyarded to my wrists and in easy reach when required. My fleece gloves now allow me to use my cameras as easily as without gloves. You want mitts with cuffs, as cuffs keep out snow and insulate the wrist – an area of high heat loss. Look for cuffs that fit snugly but don’t impede circulation.
In real cold conditions, I carry a extra pair of these thin fleece gloves in the inside pocket of my jacket near my body. This ensures I always have warm gloves to swap out when my fingers get really cold from being out of my over-mitts to long. I found that my fingers will warm up quicker this way when I have allowed them to get to cold before putting my mitts back on.
