That's all well and good when the conditions are under your control. In June I was at the Tiputini research station in Yasuni, Ecuador. It is the biotically most diverse location known on the earth. It is, not surprisingly, extremely rich with photographic opportunities, though it may be destroyed very soon because Ecuador has chosen to allow oil and gas exploration nearby.
The forest has 10 species of monkeys (including the world's smallest) that absolutely refuse to stick to any schedule not set by the sun. There is no hot water, a few hours of electricity are generated at the station every day, but outside those hours and away from that spot, the conditions are set by the amazon. In the week I spent there this year, we did not see a single person from the outside world--no plane flew over, no boat passed on the river. It's that remote.
One quickly gets used to putting on the sweat-soaked socks from the day before, because fresh socks will be sweat-soaked within an hour anyway. When you hang your socks up, they don't dry because the humidity hovers constantly near 100% (when it isn't raining outright). As a wonderful consolation, the sweat on the socks attracts an amazing diversity of butterflies in search of salt. It's charming, and gross, all at the same time.
All electronics are stored in a dehumidified building, because any electronics that are not hermetically sealed would fail within days otherwise, but that solution isn't great for optics since glass has a high specific heat, and therefore takes a long time to warm up. When taken into the forest cold, lenses fog instantly. One can warm the front elements in a few minutes, but internal elements are another matter. And the danger of internal condensation killing a lens is substantial.
I never had internal fogging with my Canon L lenses, despite years of rainforest work, because they didn't breath. On the down side, they weren't sealed against rain so I missed a lot of shots while my fancy glass sat in dry bags.
In June I spent ten minutes watching a pair of tyras (giant, social, climbing weasels) attacking a sloth. I was no more than 20 feet from the branch on which this was happening. My Canon gear was back at the station because I wasn't expecting to see anything special, and the weather was not good. It was a once in a lifetime observation. No pictures. Had I moved to Pentax WR equipment before my trip, I would have had it on me and you would be looking at pictures of an event that, to my knowledge, no one has ever documented before. Of course Pentax puts me in a quandary they may not even be thinking of, even as they are thinking 'we are building equipment perfect for rainforest conditions'. The DA* 300 doesn't breath, but it would have been the wrong lens for the tyras. Too damn close. Too much reach. But the DA* 60-250, which would have been optically ideal, is the same price as the 300, and very likely to end up destroyed by internal condensation and/or fungus, in my semi-expert opinion.
I am not wealthy by first world standards, but I am extremely privileged in terms of what I get to witness. I love documenting it, but I have no choice but to do so in disgusting socks--the conditions in which this these creatures remain are inhospitable to people and technology by nature. Like everyone else at the field station, I complain about the socks with a broad smile on my face. I will not, however, smile about a lost lens or three, especially when the solution is well known and involves a generally more robust and desirable design.
I moved to Pentax to solve the rain problem. When I return to Ecuador, I plan to have my camera out and ready, irrespective of the weather. But I can see that vapor breathing lenses are their own kind of liability. Internal zoom and focus are features. Everybody knows it. That's is why the reviews here have a symbol to alert us when a lens has them (just like WR). Those features come at a cost. What I am saying can be summed up in one sentence that is simply true:
If Pentax wishes to design DSLR equipment that will attract photographers that shoot in conditions that DSLRs from Canon and Nikon can not tolerate, then internal zoom and focus should be high priorities on WR and DA* lenses.
Bret
