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.

9 hours ago, Chris Ross said:

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.

Thanks Chris - I haven't tried warming it up a little, but will to see if it evolves.
Servicing might prove difficult for this model I think.

2 hours ago, Davide DB said:

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

Yes that's what I'm afraid of. Not sure if it's actually possible to fix such an issue. I wrote to AOI, we'll see what they say.

I had a dual pane exterior window in my flat lose its integrity some years ago. I didn’t bother with it for years as the condensation dried and calcified. When I finally took it apart, after I tired of looking through fogged glass, it was too late to save.

12 hours ago, bghazzal said:

Thanks Chris - I haven't tried warming it up a little, but will to see if it evolves.
Servicing might prove difficult for this model I think.

Yes that's what I'm afraid of. Not sure if it's actually possible to fix such an issue. I wrote to AOI, we'll see what they say.

Warming up won't cure it, just prove that it is condensed water.

On the topic of avoiding fogging you can refer to a dew point calculator. For example at 15°C and 60% humidity the dew point is 7°C. so working in conditions like that should have a good chance of avoiding fogging unless you dive in the cold waters. You could probably achieve this in an air conditioned room with the AC maxxed out and you could also place the components in a small tub purged with air from a scuba tank (very low humidity) for assembly. Here is a link to a calculator:

Omni Calculator

Dew Point Calculator

Check out the dew point calculator to calculate the highest temperature at which water vapor condenses.

Thanks for that - at the moment the traces do not seem to vary with temperature - we're currently around 22°C on land 23° in the water and humidity at around 50 to 60%.
What I tried to do is leave the lens in a ziplock bag for 24hours with some powerful dessicants, to see if it might affect condensation but nothing happened. Traces are still visible unfortunately.

1 hour ago, bghazzal said:

Thanks for that - at the moment the traces do not seem to vary with temperature - we're currently around 22°C on land 23° in the water and humidity at around 50 to 60%.
What I tried to do is leave the lens in a ziplock bag for 24hours with some powerful dessicants, to see if it might affect condensation but nothing happened. Traces are still visible unfortunately.

You would need to warm it to maybe 40° to see if it disappears, it is sealed inside and the outside humidity should have no influence. It could also for example be components in the o-rings which have leached into the air space, not too different to the way cars used to develop a film inside the windscreen due to plasticisers evaporating from the dashboard.

To be clear also, the point of the dewpoint calculation is to seal inside air that is dry enough it won't condense when diving. If the dewpoint is 7°C then you need to take it into water at least that cold to cause condensation and that should disappear when it warms up to room temperature.

I just tried warming it - interestingly enough the traces didn't change, but this did make a central condensation point appear (but seem to be more on the bottom of the lens?), which then disappeared when I cooled the lens.

However the main traces didn't bulge...
Not sure what to make of this... 🤔

Edited 23 hours ago23 hr by bghazzal

Probably the coolest point of the lens, the vapor re-distributed once it could condense somehere colder, likely the alumnium which would possibly cool faster than the glass.

I think it shows there is a trace of water in there- which would be salt water and has perhaps left a light water mark. In any case likely unusable?? If that's the case, little to lose from attempting a repair I think. You would probably need to pull apart to measure o-rings to replace.

The current specs say it's 3 group 4 element lens, which means one of the lenses is a cemented doublet quite likely so an additional possibility is breakdown of the cement, possibly caused by water entry. If you do pull it apart be sure to properly label everything so it goes back in the right order and right way up. You will need something like this to remove the retaining ring:

lens tool

I'm not sure how the seals work in these types of lenses, they might have o-ring on top pressed in by the retaining ring or is it might be like the way front elements of flat ports are sealed. Only way to find out is to remove the retaining ring.

1 hour ago, Chris Ross said:

Probably the coolest point of the lens, the vapor re-distributed once it could condense somehere colder, likely the alumnium which would possibly cool faster than the glass.

I think it shows there is a trace of water in there- which would be salt water and has perhaps left a light water mark. In any case likely unusable?? If that's the case, little to lose from attempting a repair I think. You would probably need to pull apart to measure o-rings to replace.

The current specs say it's 3 group 4 element lens, which means one of the lenses is a cemented doublet quite likely so an additional possibility is breakdown of the cement, possibly caused by water entry. If you do pull it apart be sure to properly label everything so it goes back in the right order and right way up. You will need something like this to remove the retaining ring:

lens tool

I'm not sure how the seals work in these types of lenses, they might have o-ring on top pressed in by the retaining ring or is it might be like the way front elements of flat ports are sealed. Only way to find out is to remove the retaining ring.

Thanks, it's a little odd - there are no traces I can see other than the ones I posted above, but yes, I agree that that condensation must be coming from somewhere.
At the moment the lens is still useable - the traces are not yet visible on the footage, so I'll keep using it see how it evolves.



I'm waiting to see what AOI has to say about this as well, maybe they'll know what's going on based on construction specs, and if anything can be done to save it.

The foggy mystery deepens...

AOI responded

We are unable to identify "UCL-05 LF +6 diopter" within the AOI product line. After further review, it appears this may be a product from another brand, Fantasea.

Since we are not familiar with Fantasea’s products, we recommend contacting them directly for assistance:

Fantasea

1124 Fir Ave., Blaine, WA 98230, United States

Telephone: +1 (989) 785-0540

Email: [email protected]

Which is a little odd since it is branded AOI, with a reference to their current website...

On the otherhand, Fantasea.com does not exist, so I very much doubt my email will be going anywhere...

Maybe this diopter is a ghost, and fogging its way back to the world of spirits, where the air waits 👻

Anyway, I think we're on our own here 😅

Edited 19 hours ago19 hr by bghazzal

29 minutes ago, bghazzal said:

The foggy mystery deepens...

AOI responded

We are unable to identify "UCL-05 LF +6 diopter" within the AOI product line. After further review, it appears this may be a product from another brand, Fantasea.

Since we are not familiar with Fantasea’s products, we recommend contacting them directly for assistance:

Fantasea

1124 Fir Ave., Blaine, WA 98230, United States

Telephone: +1 (989) 785-0540

Email: [email protected]

Which is a little odd since it is branded AOI, with a reference to their current website...

Seems like AOI manufactured those for Fantasea (from https://underwater.com.au/shop/ucl-05lf-macro-lens-67mm.html)

Fantasea  UCL-05LF +6 Macro Lens - cat # 5115 - AOI lens UCL-05L

UCL-05LF (made by AOI under code UCL-05L)

Edited 18 hours ago18 hr by Yorkie88
AOI not API

1 hour ago, Yorkie88 said:

Seems like AOI manufactured those for Fantasea (from https://underwater.com.au/shop/ucl-05lf-macro-lens-67mm.html)

Fantasea  UCL-05LF +6 Macro Lens - cat # 5115 - AOI lens UCL-05L

UCL-05LF (made by AOI under code UCL-05L)

Yes thanks - it seems to be that - Fantasea was probably a US distributor - anyway they don't seem to exist anymore.
The AOI branded lens I have seems to be identical to the AOI UCL-05L, which is the predecessor to the current AOI UCL-05N
Here is the 2023 AOI website listing:


which seems to be identical to my lens:
Uploading Attachment...

Edited 16 hours ago16 hr by bghazzal

I would at least send them pictures and see if they still try to deny it.