That's as I understand it.

Personally, I use only Lightroom, and hence, I haven't had any such issues . . . yet.

This should explain. If not, just Google for "sidecar or camera raw database".

That occured to me too, but when I checked at the time, it was charged and ready to fire.

Japan is not local to me.

Get real. Just how many of the users here do you you think can afford a 645D, a crop of lenses to go with it, and the return air fair to go and fetch one?

The only member here that I know has one lives in Japan, so when it breaks he can get it repaired relatively easily. The same would not be true if we followed your suggestion of flying to Japan and bringing one back to UK.

OK guys, "wrong" was perhaps the "wrong" word.

Would you feel better if I had written "set the WB to an inappropriate value for the prevailing lighting conditions"? EG: WB set to tungsten and shooting under daylight flourescent lighting.

I did mean "wrong" actually, not creative

FWIW I have my WB set to daylight too, unless I'm using flash. In which case the camera automatically changes it to flash.

Tent looks OK, either lighting method will work fine.

Good point, well presented, but surely the mating surfaces of the mount, I mean the bayonet part, determine the proximity of the lens & camera surfaces and the seal just squishes a bit.

OK, next question. If you do clean your contacts, what do you use?

WD40, switch cleaner, solvent, acetone, IPA (not the beer kind), dry cloth, tissue?

Impossible to say yet David. My issue was with the 16-50mm, I don't recall the same thing happening with my 50-135mm and no unfamiliar noises occured wither.

At home in a test environment after cleaning, it works perfectly.

It's not until a real scenario presents itself that I'll know if it's fixed or not, albeit temporarily until it happens again.

I think in the light of this experience, I'll clean my lens & camera mounts beforehand rather than suffer a similar frustration again. At least I'll know that the contacts are clean and then if it happens again, something else must be the cause.

I should add that I didn't leave the mounts wet after cleaning, I wiped them with a dry cloth afterwards. I also doubt that the weather seals on modern equipment are made of rubber, more probably neoprene, which is resistant to the effects of sea water, acids, alkalis, & lubricants.

Good point about the lubrication of the seals. If they are lubed at all it would only affect the outer edge of the camera mount though, not the electrical contact area, but you could well be right.

Anybody here on good terms with somebody at Pentax ( Chris@SRS specifically ) to ask the question?