How do weather-sealing levels differ between DSLR bodies, and are there any official ratings?

Question

I understand that higher-end DSLRs are often described as having better weather sealing than entry-level models, and similarly for some premium lenses. What I’m trying to find is whether there is any objective, published way to compare that sealing between camera tiers or models.

For example, is there any quantitative difference published for bodies such as Canon’s xxD, 7D, 5D, and 1D lines? Do manufacturers provide IP ratings or any other formal standard for dust or moisture resistance, or is “better sealing” mostly a matter of more gaskets and tighter joints in more places?

I’m looking for official guidance rather than anecdotal reports, especially for use in rain, dust, cold, or similar harsh conditions.

user496 · Accepted Answer

I'm not aware of any specific claims for immersion, rain or dust resistance made for any SLRs. I've not read every warranty, but if there was even one that covered water damage I'd be surprised.

Weather sealing is typically a combination of high-tolerance, tight-fitting joints and gaskets. "Better" sealing essentially consists of more sealing in more places.

The closest thing I know of to objective data are renderings of weather sealing locations (courtesy dpreview.com):

5DmkII:

_{(source: img-dpreview.com)}

Nikon D700

_{(source: img-dpreview.com)}

As an aside, an interesting (though apocryphal) trick from the first Gulf War to keep dust off of cameras and film was to store them immersed them in water - the catch being you needed an a camera like the Nikonos, which is rated to something like 60m depth.