I'm a genius
Yeah, that’s right. I am. I was lying in bed a few minutes ago, trying to sleep (desperately, since I have to be up at 6am to go on another tour), my mind racing trying to figure out what in the hell happened to my professional series lens. How in the world did that one end up with water in it, and not my other cheaper one.
Then it dawned on me — in the professional series lenses, there are a bunch of weather seals. Water shouldn’t get into that at all. But on the day that I was out shooting photos around the pool with it in my bag, it just happened to be insanely hot, like 35 or 36C. What I’m guessing happened is that the metal, due to heating, expanded enough to make the air-tight seals no longer air-tight. In that configuration, bits of water in my bag etc probably evaporated and entered my L series lens while it was still hot. However, immediately afterwards, I took it into my air conditioned room and set it on the table. The quick cooling probably allowed the metal and the seals to go back to normal faster than the water vapour could leave the lens. Now I have a lens with a bunch of water in it, but in a configuration where the seals are now air tight again.
My other non L-series lens doesn’t have this problem since there are no air tight seals on it — water is free to come and go into/out of it at any time. I’ve had the problem lens near the A/C unit for two days now, and the water hasn’t budged at all. It now makes sense to me because the water can’t possibly leave the lens since it’s currently air tight.
So, if I’m right, the solution is rather simple — I just have to take the lens out into the extreme heat again tomorrow, and let the seals re-expand and the water evaporate. As long as I don’t super cool it like last time when I get back (I’ll just leave it outdoors so the temperature gradually falls on it), I think it will work. Let’s just hope for a super hot day tomorrow!