Hello all,

I have a very nice AOI UCL-05 LF +6 diopter (the old model), which I use a lot as it's way sharper than the Inon UCL-165 I used before.

However, some faint traces have appeared, and seem to be inside the unit. I first noticed them underwater.
I'm guessing this means something is failing, maybe the retaining ring?

Can anything be done in this situation? It's an old model, and I'm now in Japan so sending it back to a dealer seems to be difficult.

Thanks!

Ben

All of these diopters would be sealed using o-rings I would guess, so it's possible a minute amount of water has entered - probably just a trace amount. If it's water vapor condensing then it should go away if you warm up the diopter a little. Of course it will come back when it cools off but it proves it is likely to be water vapour.

Regardless I think taking it apart and replacing o-rings would be required. You would need a tool to remove the retaining ring and be able to source replacement o-rings to fix it.

I am afraid they might be assembled in a dry air or nitrogen glove box otherwise you would always have condensation.