If weatherproofing is a big issue, the Pentax K10D (a DSLR) would be worth considering. Expensive but it's the only camera I know that is 'properly' weathersealed. Some compact cameras (Olympus) claim to be weatherproof... but read this review:.
As regards operating temperatures: the manual for my Pentax K100D says that the usable temp range is 0 - 40 degrees C. So your high-temp limit should be OK; I doubt if these temperature limits will vary much between different makes of camera..
I haven't been to the Himalayas myself but I imagine it gets a little below zero! The battery performance will drop off seriously in extreme cold, and the LCD screen may not perform well at either very high or low temps (although this is reversible and it will be OK when you revert to normal temperatures). Probably similar restrictions apply to other cameras... so you will need to keep it wrapped up (in a pocket close to your body?) if you want it to remain usable when it's very cold. or get a pocket handwarmer, powered by some kind of chemical gel in a dispoasble cartridge which can be replaced, and keep one in your camera bag... see.
The tricky parts in the choice are the fact that I will be subjectingthe camera at various points to extremely high humidity, extreme cold(himalayan base camp) and reasonably high temperatures (about 40 degCel)..
My brother's brand new Ricoh R5 survived two whole weeks in Vietnam a few weeks ago before dying from humidity (it came back to life after drying for a week though). Granted, it was extremely wet and hot, and he took no precautions when coming out of air conditioned buildings, but still, that sucks..
Get a waterproof shockproof model if you don't want problems or having to put the camera in a plastic bag all the time...
If weatherproofing is a big issue, the Pentax K10D (a DSLR) would beworth considering. Expensive but it's the only camera I know that is'properly' weathersealed. Some compact cameras (Olympus) claim to beweatherproof... but read this review:.
The cnet review is not a valid weatherproofing review. In fact it seems an insult to their reader's intelligence. Olympus is meeting specific industry standards when it make the claim of weatherproof. Both Pentax and Olympus know the standards well because both manufacturers pay more attention to this market segment than most..
All Olympus Stylus series digital cameras are weatherproofed at least as well as the K10D. Within the Stylus series the SW models are actually waterproof to specific depths and are shock resistant (again to specific standards.).
We have 300 or so Stylus series cameras. We have none used in tropical areas but have had no problems in semi-tropical areas nor in Alaska. We have used the cameras extensively in extremely dusty/extremely hot environments and have had no issues with either dust or heat. The only way they have actually been damaged is by dropping (we don't buy the shock resistant models.).
Pentax also has a line of waterproof P&S cameras - the Optio W series..
If the camera you select uses proprietary rechargeable batteries (all the Styluses)you probably buy several (4?) to cover the periods without access to AC power...
Canon, Nikon, Olympus at least all offer sealed lenses and bodies, as well...
I have a 720SW for the past year that repeatedly gets taken out in cold weather and is immersed in streams for underwater pictures of fish without a problem. Its the only out of the box camera that I know that is JIS certified for waterproof status. The Pentax W series come close.....but techniqually water resistant. The 770 SW is like the 720SW except it's been tested for extremes in temperature - waterproof, shockproof, and "climateproof"...
I can vouch for Olympus, well at least with my old stylus 410. I've had it for a few years and it's seen -20F (yes, really, although battery and LCD suffer) up to 105F, snow, rain, killer humidity, and being dropped + banged around in my pocket. It's never failed me as my side kick for my SLR, and now my DSLR. I would imagine the newer models would be at least the same if not better in that category...
Thank you all for your time and responses, I actually think I am going to get two cameras, the F31d and the 770 SW..
I have now run into my next problem and again there appears to be no definitive answer out there:.
Which Personal Storage Device?.
I have found 3 that appear to take all types of memeory card that I would ever use:.
XD Drive 2 Smart 2300 http://www.vosonic.co.uk/xsdrive2smart/.
StorVision PSC-100 http://www.stor-vision.com/psc100.htm.
I am sure there are more out there that I have not found and so any advice would be welcome..
This is a scary area. All of the devices you reference are based on conventional HDs and are subject to the same reliability issues that would affect a notebook computer HD, maybe more because the case is smaller and therefore more likely to be tossed around..
Specifically your Himalayas segment is troublesome because all conventional HDs have an altitude limitation of about 13,000'. The read/write heads in an HD actually fly on the air currents generate by the spinning disk. The air thins as we go up in altitude and beyond about 13,000' the air's too thin to support the flight of the read/write head. How high is your base camp?.
While devices such as you've listed are convenient they not the most reliable backup/storage devices. You would actually have more assurance of your images surviving your trek if you simply bought lots of the largest capacity memory cards your camera(s) can handle and simply put them away when they are filled..
I haven't done this test on xD or SD cards but I've actually run CF through a full wash cycle, let them dry thoroughly and not lost any images. Before someone asks, no it didn't clean up the noise or the chromatic aberations in the images...