Hi, 

Attached you find a video Which shows that I can not open the 35.5 n120 to n100 adapter Anymore.

The problem is, I can’t get the cam / Lens out if I cannot open this because it’s not going over n100!

it’s stuck!

Do you have any trick?

Also, the screws with the Allan key were kind of stuck, and I can’t open from outside…

Camera and Lens are trapped inside :-/

It’s the special 8-15mm with 2x TC combo - zoom ring / big lens blocking from release…

First time something like this happened…

greetings 

Michael 

So the lens is too big to fit through the N100 port is what you are saying? Is it a port or extension on front? Assuming it must be a port which you can't take off to access the lens. If it's an extension of course you can remove the port from the extension then release the lens and extract body then take off the adapter/extension. I thought an extension went with the 8-15 setup?

If the hex in the allen head is still sound, you could try some penetrating oil dripped from above and leave it to do its work for 24 hours and try again? It seems to me it should be the safety lock release as inside it just turns a cam to raise up a blocking piece that prevents rotation and removing that cover should allow you access to allow that tab to turn.

3 minutes ago, Chris Ross said:

So the lens is too big to fit through the N100 port is what you are saying? Is it a port or extension on front? Assuming it must be a port which you can't take off to access the lens. If it's an extension of course you can remove the port from the extension then release the lens and extract body then take off the adapter/extension. I thought an extension went with the 8-15 setup?

If the hex in the allen head is still sound, you could try some penetrating oil dripped from above and leave it to do its work for 24 hours and try again? It seems to me it should be the safety lock release as inside it just turns a cam to raise up a blocking piece that prevents rotation and removing that cover should allow you access to allow that tab to turn.

Hi, thx so far ! It’s:

Sony A1 plus Sony 2xTC plus Metabones plus 8-15 canon. Nauticam housing, 30mm n100 extension plus 35.5 n120/n100 adapter plus 30mm n120 extension.

I try WD40 to help the Allen key.

My camera shop told me to try warm water…

Every other recommendation is highly appreciated!

Edited August 31Aug 31 by Michi

WD40 is pretty marginal as a penetrating oil. My favorite is Kroil, although others like PB Blaster, etc.

6 hours ago, SwiftFF5 said:

WD40 is pretty marginal as a penetrating oil. My favorite is Kroil, although others like PB Blaster, etc.

Thx. But I am at the end of the world and even WD40 is luxury but I will give it a try!

10 hours ago, Michi said:

Hi, thx so far ! It’s:

Sony A1 plus Sony 2xTC plus Metabones plus 8-15 canon. Nauticam housing, 30mm n100 extension plus 35.5 n120/n100 adapter plus 30mm n120 extension.

If I'm reading correctly it's N100 extension, adapter, N120 extension, port. Problem is with N100-N120 adapter.

So can you remove port from port from 30mm N120 extension? This should be possible. If you can do this remove the port. Then use lens release button to remove lens then remove body, then remove combined N100 extension and N100-N120 adapter. You might be able to move the locking mechanism from inside then.

22 minutes ago, Chris Ross said:

If I'm reading correctly it's N100 extension, adapter, N120 extension, port. Problem is with N100-N120 adapter.

So can you remove port from port from 30mm N120 extension? This should be possible. If you can do this remove the port. Then use lens release button to remove lens then remove body, then remove combined N100 extension and N100-N120 adapter. You might be able to move the locking mechanism from inside then.

I was able to fix the problem overnight with WD-40— I was able to get the yellow marked screws out, open the lock mechanism! I had to shake the whole case, and then it finally popped open by rotating at the same time!!! As you can see in the second picture, there’s no other way to access it. I’ll make sure to always have the right Allen key and some oil on hand from now on. The Nauticam set of keys doesn’t quite fit the N100 on the N120. Better to get something that works 100 percent! This issue was really the worst problem with a whole set up which affected everything… Best regards and thanks to everyone for the help :-))

Wow, well done, Michael. Scary moment. I hope the rest of the trip goes well!

On 9/1/2026 at 1:11 AM, Michi said:

I was able to fix the problem overnight with WD-40— I was able to get the yellow marked screws out, open the lock mechanism! I had to shake the whole case, and then it finally popped open by rotating at the same time!!! As you can see in the second picture, there’s no other way to access it. I’ll make sure to always have the right Allen key and some oil on hand from now on. The Nauticam set of keys doesn’t quite fit the N100 on the N120. Better to get something that works 100 percent! This issue was really the worst problem with a whole set up which affected everything… Best regards and thanks to everyone for the help :-))

The right tools will always help. But prevention is even better. Looking at you housing in the photos it seems to me there's deposits on there, in the video you posted and with the surface between the ports/adapters.

I would suggest a good long soak after any diving session. Also recommend applying some grease to your screws holding on the lock mechanism. Should make them easier to remove. Does the mechanism rotate freely now? It should rotate quite easily- if it is stiff perhaps it needs service, there will an o-ring on the shaft of the control that unlocks the port and the shafted should be lubricated.

If the lock is sticky I'd recommend rotating the ports slightly, mine doesn't want to lock or unlock if they are fully rotated together but instead need to be slightly backed off.

On 9/2/2026 at 10:25 AM, Grantmac said:

If the lock is sticky I'd recommend rotating the ports slightly, mine doesn't want to lock or unlock if they are fully rotated together but instead need to be slightly backed off.

Thx for the advice! So you just rotate them a bit in direction of the line (away from Circle) and try to unlock again?

On 9/2/2026 at 10:17 AM, Chris Ross said:

The right tools will always help. But prevention is even better. Looking at you housing in the photos it seems to me there's deposits on there, in the video you posted and with the surface between the ports/adapters.

I would suggest a good long soak after any diving session. Also recommend applying some grease to your screws holding on the lock mechanism. Should make them easier to remove. Does the mechanism rotate freely now? It should rotate quite easily- if it is stiff perhaps it needs service, there will an o-ring on the shaft of the control that unlocks the port and the shafted should be lubricated.

Thx for the advice! Yes, now like before… rotate without any scratching Sound etc. I do a lot of muck and The sand and salt creeps in everywhere! I am also in a lot of destinations where I can not let it soak… : Small fishing boats / villages and no 24/7 water Infrastructure with Water supply… amazing diving but no rinse tanks! And after those Trips I let it soak for several days and try to really take good care with warm Water and cleaning… but in our case before with This incident: I was having it after every dive day for 10 min in a tank in around 30 cm depth… very very Strange… I will send the 35.5 to a Service inspection and let everyone know what they say because this can cause a really big Drama for every user … I can Imagine people can’t Pack properly for flights etc when not able to Open… Next Post will be some photos after all negative at least some positive…

Edited September 9Sep 9 by Michi

On 9/1/2026 at 3:48 PM, TimG said:

Wow, well done, Michael. Scary moment. I hope the rest of the trip goes well!

Thx a lot. I really appreciate the help and thoughts from everyone!!! Here We go with the first four photos from the wide angle / fisheye Workshop - after retutning yesterday ( I will post a few more in the other Forum) with 8-15 with 2xTC …

1 hour ago, Michi said:

Thx for the advice! So you just rotate them a bit in direction of the line (away from Circle) and try to unlock again?

Try it both ways, mine is very clear when it lines up correctly and it's not 100% on the mark.

Also a cloth soaked in hot water should help if you don't have a lot of water available.

29 minutes ago, Grantmac said:

Try it both ways, mine is very clear when it lines up correctly and it's not 100% on the mark.

Also a cloth soaked in hot water should help if you don't have a lot of water available.

Thx! Cloth is an interesting idea! I will give it a try…

A good substitute for Kroil is a 50/50 mix of automatic transmission fluid and acetone. I have also used alcohol in place of acetone with moderate success.

You can certainly travel with a small tube of penetrating oil, and having been in some very remote locations (where fresh water was in short supply) I now will communicate with the dive resort or homestay ahead of the time to ask if they can order (or store) an extra 5 gallon (or 18.9 liter) jug of water just for my use. I always offer to pay for this...

In Sulawesi the water will cost about $2 USD, and a new jug (if they charge you for it) will be $6 USD. I have offered resorts or home stays $20 USD to have a jug just for my use (for camera gear) - I haven't had a problem getting this (although sometimes I've had to wait a day or two to get it after arriving).

There are several collapsable rinse buckets you can get (that can double as containers for your camera rig in small boats). No issues traveling with one of these.

3 hours ago, OneYellowTang said:

There are several collapsable rinse buckets you can get (that can double as containers for your camera rig in small boats). No issues traveling with one of these.

I always travel with a (now) Kraken was (Cinebags) Grouper XL as a portable rinse tank. During the journey is carries lots of my gear in the cabin. A bit pricey but they are excellent travel bags and rinse tanks.