Hello,
Finally a topic I have some experience on.
I will start with cameras and lenses:
I shoot Contax 654 for going on 11 years now. 99% Nature and landscape photography. I know, the Contax is not advertised as weather-sealed, either body or lenses. Nevertheless, with tens of thousands of shots, I have never had a failure. The following are examples of conditions that I have shot in, multiple times (not just once):
Yellowstone in January and February. Blowing snow. Temperatures down to -25F (that's right, F). Steam in geyser areas turning immediately to frost on the body. Moonlight long exposures of up to 20 minutes at temps from -10 to -25 F.
Alaska for 3 months. Cool weather and rainy drizzle falling on camera body. Salty spray shooting from boats.
Death Valley. Heat, blowing sand. Temps up to 90F.
Arizona desert cactus bloom. Fine dust, temperatures up to 115F.
Florida various times year round. Very high humidity (95% plus) going in and out of air conditioning. Salt spray.
These are just the extremes. Many days/weeks/months of typical mountain/desert/river/red rock/coastal shooting in humidity, heat, moisture, fog that most would consider more moderate or normal conditions.
I can tell you, the Contax 645 is probably the most solid, tank-like, durable, reliable and easy to use system out there. Of course, I take reasonable precautions to protect my gear from the elements (umbrellas, putting it right back in the case, dry packs, heat packs in the winter, and such) but I must admit that my gear has been drizzled on, snowed on, sand-blown on, and similar. I also religiously clean it at the end of each day and make sure it is totally dry.
Have no fear, this system can take what you dish out. Still, I wouldn't shoot it in open rainfall or direct water splashing, but that would eliminate, maybe, .01% of its capability (and you can get EWA marine bag cases that allow this type of shooting as well).
The new Leica advertises complete weather sealing and it looks like the real deal. But, let me see, for the price of the Leica body and one lens you can buy an ENTIRE Contax system with body, vertical grip, NINE Carl Zeiss lenses (from 35mm to 350mm APO including what is still regarded by many as the finest 120mm 1/1 Makro ever made and 80mm f2 one of the fastest MF lenses ever), various finders, a flash, and probably still have $9K to put to a digital back. Plus, use Hasselblad lenses with an adapter.
As for digital backs for heavy outdoor use, Phase One is the best choice. Their durability videos and their reputation for durability speak for themselves. They have no fan louvers or other easy ways for the elements to penetrate into the back and can handle any temperature range you throw at them. Also, if you are a landscaper I assume you want long exposures from time to time and Phase is the only game at all for exposures of 1-2 HOURS. There is no contest as other backs seem to pride themselves if they can go 1-2 MINUTES.
I say this as a person dreaming to afford a p45+ one day, and I would put my hard-earned money there.
The new Pentax 645 D is also advertised as weather-sealed but is still a long ways off from offering a complete system and won't be available for many months.
If you need something now, I would get on ebay or KEH and put together a Contax 645 with the lenses you need, and then get any of the Phase One "plus" series of backs (the plus designates the long exposure ones).
Hope this helps,
Guy
