I'm glad to find this post because I have been looking for a place to give my review of the Nauticam NAU-17216 and the optional TTL converter. I apologize for the length of this post but before anyone spends their money I'd like them to hear about the issues I've had, which I consider to be very serious.
First I would like to mention that I am very new to underwater photography. I previously owned a Sealife camera so this is my first serious camera for underwater use.
The controls on the housing feel very solid and after shooting 38 dives in the Philippines I can say I really think Nauticam did a great job with most parts of the housing. I love the leak detector.
There are two issues that I have had just with the optional TTL converter. It was very difficult to install. For the money that the housing and converter cost, the fit of the converter is terrible. The plastic circuit board is not shaped properly, so it does not sit flush into the housing. As a result, when you try to install the screws for the converter, they will not reach because they are too short. To be honest, even after modification (I had to sand the edges of the converter with a nail file to get it to fit) it still is not installed to my satisfaction.
The second issue with the TTL converter is that once it fits into the housing, and you try to secure the converter with the screws provided by Nauticam, if you tighten the screws, at all, one of the two LED lights will fail to light. I had this issue with two different converters. The first converter had an issue with the left LED lighting. The second had a problem with the LED on the right side.
The interesting thing is that the converter will fail to light on one side while in the housing, but when you remove it from the housing, both LEDs fire correctly. This leads me to believe that the problem is that even after sanding, the circuit board is still too wide and as a result there is a very small gap between the converter and housing and when you install the screws it applies a slight pressure to the circuit board which disrupts the circuitry somehow. This is just my best guess.
However, I must say that once the converter was finally installed and I actually got it functioning properly it works well.
The second issue I have had is with the locking mechanism on the housing. A lever on the outside of the housing rotates a disk with slots inside the housing which appears to apply pressure to the side of companion slots from whatever port or extension ring you are using. It's hard to describe in words but this doesn't really lock anything to the housing. It just increases the pressure required to dislodge whatever is inserted.
A much better solution would be if the slots for the port or extension sat deeper into the housing so the locking ring could rotate fully in front of each slot and actually lock the port or extension securely to the housing.
Why am I going through the trouble of writing this out? Because when you install a 230mm glass dome port, you need to be very careful when you pick it up. After using that port several times, I started feeling more comfortable with it. After "securely" inserting and locking the ($2k) glass dome in place, I picked it up to carry it across the room and after 3 steps, the glass dome fell out of the housing and went crashing onto a tile floor on the first night of a month long diving trip. Pieces went flying. I was in the Philippines when it happened so there was no hope of immediate repair.
Luckily what broke were just the 15 or so (plastic) plastic screws which hold the plastic hood to the back of the glass dome. Thank you to Keith from Sea Explorers in Malapascua, Philippines for figuring that out. You saved my trip. So, don't trust the lock. Even when it looks secure.
To Nauticam's credit, if it wasn't for the excellent leak detector and vacuum valve that they have in the housing I never would have tried the glass dome after the fall. Even in just an empty housing. So kudos to Nauticam on the leak detector and vacuum valve.
All in all, after spending close to $15k between housing, accessories, camera and lenses, I'm less that thrilled about my Nauticam housing secondary to the TTL converter and Port Locking Ring.
I think I would check to see if Seacam has a housing. The cost difference between my Sealife camera and my Nauticam setup are substantial (close to 20x the cost) but the difference in quality of pictures is substantial. Maybe it would be worth a little extra to get a Seacam housing?
I welcome any thoughts.