[Frank29]

Ok, so I was doing some deep bush landscape photography yesterday, and put my Pentax FA 100-300 zoom in my pocket near a creek, bent over, and flipped it into the water. Didn't notice it for about 10 seconds then scooped up the floating lens. Took it home, shook it all out, left it on a heat register all day to blow warm air over it. Then used a blow dryer to dry it out as best as possible. Problem is - there is significant beaded water between at least the outermost lens and the one beneath that.

I am going to try to remove the outer lens and dry these two out, but am quite leery to get into it. But it I don't, it's pretty much useless anyway. I highly doubt a dessicant will pull all this water out, because it must have seeped in around the lens thread.

Any thoughts or other ideas? Any expertise on lens disassembly I can tap into? (This is the F4.7 to 5.8 silver plastic 100-300 zoom lens)

Frank

[tvdtvdtvd]

Put the lens in a box filled with rice and keep in a dry place. That will pull the water out, but you will still likely be left with
mineral deposits, (water spots), after the water has evaporated.

[TwoUptons]

I haven’t had a 100-300 in a while, but I think you can get into the front with a lens spanner...

Of course that means you’ll need a lens spanner...

Mine’s paid for itself and then some.

-Eric

[UncleVanya]

I wonder, given the relatively inexpensive cost of the lens id it would be better to just replace it. Dirt may have migrated in, and over time even if it works it may degrade in the future. Otherwise dismantle and wash with distilled water, dry and reassemble.

[microlight]

Sorry to hear this; this kind of thing is always a gut-wrenching experience.

[normhead]

When my FA 50 macro suffered a singular fate, I simply removed the back plate and put it in in front of a hair drier far enough away so the the air was a bit cooled. I also did the same with my Tamron 90. Both lenses still work flawlessly, but, I bought a WR DFA 100 macro, to replace both lenses when around water.

[arqjaviergarcia]

Well I don't know about water, but I have a pentax A 50mm f2, had it in a drawer forgoten, when I found it was fungus inside lens, so look for a tutorial of how clean it, that was a long process learning, but at the end I did it, now it is working with some loses in coating but still good enough.
Maybe was easier get another, but this was a gift from my father, so .....

[Not a Number]

I would have rinsed it out with distilled water before drying it out. This would have flushed out most of the minerals that cause water spots.

When I dropped my MP3 player into the dishwater, I opened it up (with the aid of a guitar pick) removed the battery, rinsed it out with distilled water in put it in a plastic bag with a closet dehumidifier pack for a week). It's been 2-3 years since that happened and all the switches and the display work correctly.

[Kozlok]

When you put it in the rice put something under the mount end so the front element is lowest. That way if you have a mineral deposit it’s on the easiest to clean end

[Frank29]

Well, I made an attempt at repair of the lens, but unfortunately what I now have is a zip lock bag full of parts.... I got a proper pin spanner off amazon, and got the outer ring of the front element off, but could not loosen the outer element for the life of me. So I thought, well it's basically worthless anyway, so I proceeded to dismantle the back end. Mistake - when I took the first plate off, 4 or 5 little electrical contacts and springs flew out at me, and I new I was in trouble. I went a little deeper, and eventually started twisting things and got the front barrel off with a twist and pull (which might have worked, had I done that first!) Anyway, here are a few photos of the remaining mess. Now I'm going telephoto lens shopping, I guess....

[VSTAR]

I can only imagine the sound that came out of your mouth once it was completely disassembled ! Especially since a used one on ebay is $70-80 !!!
If you do not get it back together....file under learning session. Someone sold me a 17-28 once....went to the trouble of having them post on ebay so we could make the transaction. Got it...and the aperture blade was stuck. Turned out owner had loaned it out in the past and never checked it before selling it. I took it apart...not as much as your 100-300. Told my wife to please not enter the room. After much prayer...got it straightened out and back together. And now 2 years later the aperture blade is stuck again!

[MotoRider]

You had a go with nothing really to lose, I've sent a lens away for cleaning as I know my ability to do these type of things is pretty poor. The normal outcome is to go shopping afterwards.

[UncleVanya]

Well, I made an attempt at repair of the lens, but unfortunately what I now have is a zip lock bag full of parts.... I got a proper pin spanner off amazon, and got the outer ring of the front element off, but could not loosen the outer element for the life of me. So I thought, well it's basically worthless anyway, so I proceeded to dismantle the back end. Mistake - when I took the first plate off, 4 or 5 little electrical contacts and springs flew out at me, and I new I was in trouble. I went a little deeper, and eventually started twisting things and got the front barrel off with a twist and pull (which might have worked, had I done that first!) Anyway, here are a few photos of the remaining mess. Now I'm going telephoto lens shopping, I guess....

Offer your parts to those who might want them. The springs and contacts are often needed to replace lost ones.

[Frank29]

Sure, if anybody want this lens (bag of lens parts) for parts, they just have to pay the shipping and it's their's!

[Grippy]

Well done for having a crack at it, now you've got a good excuse to buy a new bigger lens