5D Mark III operating temperatures at high altitudes

[ddashti]

Is anyone aware of what the operating temperatures would be for a situation where the Mark III would be taken to an elevation of almost 4 km (2.5 mi) and used straight out of the bag?
Example:
July, mountain top, sunrise, 4 km / 2.5 mi above sea level

[opelio]

In the past year I used a Mark II in Norte Grande- Cile at 4700 mt altitude (2-3 degrees) just came out from the heated car. No problems. Nor Nikon D700.

[Drizzt321]

If you're hiking/climbing up, should be just fine since it'll adjust somewhat to the ambient temperature while you're climbing. Unless you're dealing with freezing temperatures, in which case you definitely need to make sure it's at ambient before putting the battery in (need to keep them warm!) and using it.

[hollybush]

Is anyone aware of what the operating temperatures would be for a situation where the Mark III would be taken to an elevation of almost 4 km (2.5 mi) and used straight out of the bag?

I have no idea how the camera would do, but if you mean going straight from sea level by plane or land humans don't do well at all. Google "altitude sickness" and read up on acclimatisation. It can be fatal.

At a rate of altitude increase safe for humans (days), your camera will have time to equalise its temperature with the outside. The pressure, of course, is instantaneously equalised, since your bag is not a pressure vessel. I think we can assume that a 5D Mark III will not explode at 4000m. In fact I'd guess it's been built to handle shipping by air at 10,000m.