As the camera meter is looking through the lens, and hence also the filter, you can meter as normal.

There are some recognised standards for waterproof cameras and there it gets very specific, but for DSLR lenses it's new territory.

I'd translate the two paragraphs as: DA* lenses are dust proof and water resistant, but not waterproof. So, we've seen what can be done in the desert on YouTube, but the norm would be no actual immersion in water but a high level of sealing against rain and water.

WR lenses have a simplified version of the same technology and are not dust proof, but will resist bad weather conditions such as rain.

It indicates to me clearly enough what I would and wouldn't do with these lenses, and so far no problems have ensued.

It's probably the right starting price for the type of lens and the superior manufacturing quality. It will fall with time.

As a lens it clearly has its own character, not perfect lab results, but capable of outstanding performance when stopped down. How this makes it perform when wide open remains to be seen.

With all lenses, they can have practical uses that make a lab test superfluous in many ways. Hence the imperfect but very nice 18-135mm WR.

I can't afford £850 for this, so it makes it academic at the moment.

Samsung also make sensors, as we know, and there may well be others.

The 645D is a Kodak sensor I think?

That's a fair point Russ. It's better in one sense to under-state an item, then the buyer will find it exceeds their expectations. If it's the other way round, or perhaps we like something ourselves and get carried away then disappointment results.

It's because the balance has been shifted strongly in favour of the buyer, except it doesn't work that way.

In a similar fashion, when postage rates are capped the starting price has to go up...nobody wins.

It's more than imply and pretty specific in the lens instruction manual.

Hope that helps!

I'm not sure that "forced on" and "at the whim of" are really how it works. It's equally so for all manufacturers. It's just continued development, which we expect. Otherwise, we might still have 6MP DSLRs. Improving those was an aim of all camera manufacturers, not something that was forced on them by sensor manufacturers, surely?

The 135-380mm could be what I'm looking for. I'm moving towards wildlife photography and the extra reach would be very handy.

Good stuff Ken, I'll look forward to seeing your film sometime.

Glad it helped!