[daacon]

I was in Mexico recently with all my gear (in my sig below) I used the Tamron18-250 more than the others , but I did make a point to shoot with every lens, cause I dragged'em all down there ! Anyway to the question.

It was around 25 - 35 Celsius (77 -95 F) most of the time and not too humid (for being on the coast). The mornings were more humid than the days. The AC in the room was set around 21 - 22 Celsius (68 - 71).

The last few days I noticed when I first put on the Tamron18-250 there was condensation inside the lens affecting the picture. At first I thought crap it is done for. The first day I just kept it in the bag. The second day I checked again outside after the camera sat in the AC all evening same thing. Later that day (it was drier by then) I checked and the condensation was gone. Lens was spotless with no visible affect to picture IQ. None of other lens appeared affected by the weather and were fine (maybe one day the DA12-24 had a little hard to remember) I do know the 105 sigma, Bigma and Fisheye were always fine.

So do you think there is seal that is gone somewhere ? Is this a normal occurrence for such a climate change ? Should I get the lens looked at and repaired ? Has not happened since I have been back home mind you it is still winter here - snow on the ground, any moisture at this point is still in solid form ! Anyone else experiences this ?

[Canada_Rockies]

I was in Mexico recently with all my gear (in my sig below) I used the Tamron18-250 more than the others , but I did make a point to shoot with every lens, cause I dragged'em all down there ! Anyway to the question.

It was around 25 - 35 Celsius (77 -95 F) most of the time and not too humid (for being on the coast). The mornings were more humid than the days. The AC in the room was set around 21 - 22 Celsius (68 - 71).

The last few days I noticed when I first put on the Tamron18-250 there was condensation inside the lens affecting the picture. At first I thought crap it is done for. The first day I just kept it in the bag. The second day I checked again outside after the camera sat in the AC all evening same thing. Later that day (it was drier by then) I checked and the condensation was gone. Lens was spotless with no visible affect to picture IQ. None of other lens appeared affected by the weather and were fine (maybe one day the DA12-24 had a little hard to remember) I do know the 105 sigma, Bigma and Fisheye were always fine.

So do you think there is seal that is gone somewhere ? Is this a normal occurrence for such a climate change ? Should I get the lens looked at and repaired ? Has not happened since I have been back home mind you it is still winter here - snow on the ground, any moisture at this point is still in solid form ! Anyone else experiences this ?

The Tamron is not a sealed lens. The way to prevent condensation when going from cold to hot is to put the gear in a baggie until the condesation is gone from the baggie.

[daacon]

The Tamron is not a sealed lens. The way to prevent condensation when going from cold to hot is to put the gear in a baggie until the condesation is gone from the baggie.

Sorry I should have been more specific I realize it is not a weather sealed lens like a da* . It was not really hot to cold 22 degrees C to maybe 25 - 30 C, and it was the only lens that had this as an issue. I was just wondering if maybe there was a crack or something anyway moot point I think until I get into a tropical climate again haha.

[benplaut]

Don't worry too much about it... we have these problems regularly in the hotter parts of the world, never seen it do any damage.

[Peter Zack]

The baggie idea is a good one Dave if you are ever in similar conditions. But the issue is most likely the AC. the AC unit sucks all the moisture out of the air and cools the lens down some. So the second it hits the hotter outside, humid air the moisture is collecting on the glass. Then you zoom the lens and that warm, humid air gets sucked inside. The lenses that extend to zoom, need air to fill the increased space so they aren't that tight. To avoid this, weather sealed lenses are all internal zoom/focus mostly.

[daacon]

Thanks for the replies all , it makes sense - this was my first tropical visit with the gear - good to know it is expected. Thanks again.