So, a colleague of mine lent me a lens about a year ago to use on a trip to Puerto Rico. I used the lens on the trip and returned it. He just used the lens for the first time since then and said that there's a lot of condensation in the lens and hopes that I will pay for the repair. I wanted to get some feedback about how fair people think that may be. Some additional notes: -the lens is an older, currently discontinued, non-weather sealed Canon L-series lens, so it was probably purchased some time between 1993 and 2002. -the offer was to let me borrow the lens for free, which was obviously generous -when he lent me the lens, it was stored in a neoprene lens sleeve, but it had no caps on it (front or back). He hadn't used the lens in years at that point. So I bought caps for the lens before taking it on the trip. -I used the lens near and on a beach in a resort, but at no time did the lens get wet or anywhere near spray -The lens owner moved in the last year, and discovered the condensation recently after taking the lens out after arriving on a trip to Europe. -I wouldn't say that the lens seemed tack sharp when I used it. Obviously that may be my technique, but it probably wasn't in perfect condition after 10-15 years of use by a former professional photographer. Two questions: 1) Do you think I have complete, shared, or no responsibility to pay for the repairs? He wants to send the lens to Canon upon return to the U.S. 2) What should he do while still on vacation to minimize damage to the lens? I've seen suggestions of silica gel, drying on a radiator, and other ideas looking around on the internet. Anyone have success with any of these?