Alaska: 5D2 or 1D4

[trojdor]

Going from CA to Fairbanks...I don't think you quite grasp the weather difference. As I type this it's 60degF here in Colorado Springs. Wunderground shows a current temp of 9 below zero in Fairbanks. Fairbank's historic lows this date: -41degF.
They're predicting a blistering high of 1 for tomorrow....and this isn't even the cold season yet.
In the summer, AK is an incredibly beautiful state. But there's a saying in AK: "We live for the summer...BOTH weeks of it."   

[Rick Massie]

Typical Vermont Weather Report: "6-42 inches of snow followed by a tropical blast with thundertorms in the afternoon followed by a deep freeze and no sunshine for a month"  Lets just say that it gets cold enough where even the heariest of us won't go out.   

that's the key thing, will you really be outside shooting when the weather gets extreme?  or will you be inside enjoying a 40 and wondering why it's got to be so dark all the time?  any of the 5D series cams should be able to handle things just fine, unless you're planning on dogsledding the Yukon and documenting it.  the main thing that will happen will be your batteries draining really fast.

I followed the Yukon Quest (dogsled race from Whitehorse, Yukon, to Fairbanks Alaska) as the official photographer in 2011, and had only a 5D (original), 30D, and a 20D. I had no issues, and it was -40 to -50 the whole two weeks. It's a matter of taking care of your equipment when moving indoors and outdoors a lot (big ziplocs seem to help!) and making sure your spare batteries are kept warm when not in use. So a 5D should be able to handle it, unless the AF of the 1D series is a must for you. And I actually had better luck with the 30D AF than with the 5D.

Hope this helps!

[verysimplejason]

5D3 + 17-40 + 70-200 + 50mm.  Definitely the lightest combo lens and body you'll find.

[wle]

Put your money on glass and don't worry about the body. 5D2, 5D3, 1D??? won't make much difference. By 'glass' I mean get the fastest you can. 24mm f1.4L would be really nice. 16-35 f2.8 or 28mm f1.8 work too. I say this because you're probably going to want to photo the Aurora.

Want thoughts on cold weather photography from somebody who does quite a bit of it, and does it quite well, scope out -

http://www.expeditionsalaska.com/ramblings/2011/11/21/cold-weather-photography-clothing/

[Don Haines]

I live in Canada and shoot all winter long with temperatures down to -25C where I live and down to -60C when I get sent to the islands for work.... Have used a 60D, 5D2, and 7D in those tempertures with no problems.

Recomendations are:
#1 - spare battery in a warm place
#2 - do NOT put the camera under your coat to keep it warm, the humidity there will end your shooting.
#3 - keep your fingers warm.
#4 - if the shoulder display or rear display get cold enough to stop working, pack it in for the day.
#5 - when outside, carry the camera in a padded bag... the padding adds insulation and slows down heat loss
#6 - before you come in after a good long time in the cold, put your camera and lenses in plastic bags, seal them, and let them warm up for an hour or so inside before you take them out of the bag.... this will solve most of your condensation problems.

second most important, take lots and lots of pictures and make sure they are backed up.
most important, have fun!

[jhaces]

#6 - before you come in after a good long time in the cold, put your camera and lenses in plastic bags, seal them, and let

I'd add silica satchels to the bag; speeds up the process and makes it pretty much foolproof.