There's no ruggedness scale, so we can't say 7 or 8.5..

It's a well built camera, but it is not designed to fall down a mountain..

For that, you need a 1D model, and it will still matter what rocks it hits..

I certainly would not worry about the camera, assuming I could put it into a bag..

There's also a product with armor in it's name; it's a rubber-like "coat" that goes over the camera, with holes so you can still rech the buttons. Around fifty dollars. Buy one of these..

Battery; depends on how many pictures you take, whether you use autofocus for all shots, how often you use the built-in flash. That said, you can get several hundred shots from two batteries with no problem at all..

BAK..

Reasonably rugged but they are designed and made as consumer electronics devices, not to military specifications. With care it should do OK, keep them dry, clean and don't beat them on things. You might want to look to alternative battery possibilites, like an external battery pack, battery grips, etc., which allows for use of a larger, longer lived battery or swapping in AAs. Also, the altitude may result in it being colder so that can impact battery life as well...

Take a look at the Pentax K10D. That camera is actually made to deal with harsh conditions, and isn't a lot more expensive. This should give it a clear advantage, even if the lenses aren't weather sealed yet.http://flickr.com/photos/iskender..

Yes, there can be issues with *any* camera at altitude, and temperature... but the determining factor on batteries will be how many shots will you be taking - at cold, the battery life could be as short as 250-300 shots on a charge (no flash).. your storage might be the larger issue - how many CF cards are you going to carry? also, keeping the camera padded and reasonably warm is more important... (even buried in your pack is better than hanging loose).. in pack, my 350/XT is quite good down to -20C for the occasional shot...

I would suggest at 3 batteries to be able to keep them warm, otherwise, knock yourself out!.

Cheers,S.**My XT IS Full Frame APS-C/FF of course!*****So is my 5D 35mm/FF**..

Canon 400D is the least rugged currently produced DSLR..

Edvinas..

I have a Canon 400D as a backup camera - I wouldn't call it 'rugged'..

The main issue is going to be if you drop it / fall on it / bang it on a rock. Remember that you're going to be climbing a steep, icy mountain - and if you get into a hairy situation your camera will be less important than your instinctive reactions - hence needing a camera capable of taking a knock or two..

Although I'm fully Canon set up - the thing I hear to be good in such situations (without blowing 8 grand on a 1D) is Nikon's D200.

Weather sealed, solid body - sure it'll cost you a bit more than the 400D - but it's a hell of a lot more tough..

As far as your batteries go - I'd agree with the others - take 3 or 4 back-ups, as the cold will drain them way faster. If you buy 3rd party ones they're pretty cheap, so it isn't worth the risk not to have enoughhttp://www.instantphotos.co.nz..

That the 400 is, as has been said, the least rugged dSLR going you can tell when you pick it up the first time. Battery life for the 400 is lower than alternatives because batteries are big and heavy and the 400 has a small one - that is partly why the camera is small and light. An alternative is the Nikon series, especially the D80, but also the D40, which have much bigger batteries. In the D80's case you can get 2700 shots on a single charge. Plus Nikon makes a battery grip that takes 6 AA batteries (nothing similar for the 400, as far as I know). For the D80 Nikon say this gives you 200-300 shots with ordinary alkaline AA and more with NiMH, so you can take 30 AAs (in the bag the porter carries) as back-up.

They may register empty when very cold and need warming up to work: keep a spare battery in a pocket next to your skin...

I just got back from a 8 day festival..

During those 8 days I used more or less 3 batteries. I can't really say if I used 2,3 or 4, since I always used a battery grip with 2 Battteries in it. I used up 2 Batteries completly, the other batch is probably still at 65% full just a guestimate, no way to tell..

Those ~3 charges gave me about 2000 pictures (no flash, autofocus, jpeg). I also had to do some onsite culling, since I only had 8 GB of storage..

Since I was in avery warm location I would advise you to take 4 Batteries, 2 of which you always keep close to you body to keep them warm..

There definately is also a Canon Battery grip, which can take either two Canon Batteries or 6 AAs..

I usually always use 2 Canon Batteries, but it can be very convinient to use the same batteries for your camera and your flash..

As far as ruggedness goes, I would say that the camera can stand being knocked around a bit..

But as soon as I stop taking photos, I would try to put it in some kind of bag / sleeve..

I think of the biggest problems would be the protecting LCD and avoiding dust, moisture and sand. As others have pointed out, the 400D isn't sealed, if you want that you will have to move to the more expensive 1D series or the Nikon D200. I think Pentax also has a sealed entry level DSLR..

Bye,Philip..