One thing I meant to say yesterday was to always be careful when lenses end up very close to the glass - I’ve seen a few times problems when the housing compresses underwater (more port sections - more o-rings - more compression), the port then pushes the lens and camera back in the housing enough that the push buttons on the back of the housing start activating.

1 hour ago, Alex_Mustard said:

One thing I meant to say yesterday was to always be careful when lenses end up very close to the glass - I’ve seen a few times problems when the housing compresses underwater (more port sections - more o-rings - more compression), the port then pushes the lens and camera back in the housing enough that the push buttons on the back of the housing start activating.

Good advice, Alex. In fact, the shortest option is really tight (basically the space of a business card), so I’m a bit worried about it. Anyway, I also tried the 97mm + 20mm combo and it's fine — there’s no vignetting with the close-up lens (SMC-1) mounted on the flip. So this is probably the best option: fewer extension rings, less bulky setup... (until the proper port will be available)

I suppose I should chime in here. I've had several requests for 3D printed extensions, so I recently went ahead and designed/tested an N100 version. I made the prototype 17.4mm, as I believe that is the reported length difference between the Sony 90mm and 100mm lenses (if anyone knows for sure the ideal length for the extension for the 100mm, please let me know). It's simple to do other lengths as well (it might be tough to do shorter than 15-16mm with the current design, though). It has a bayonet but not a port lock, though that shouldn't be an issue if you use a vacuum system. I tested it to over 100m.

Obviously, a 3D printed plastic extension is not nearly as nice as an aluminum one from Nauticam, but I just thought I'd let people know about this option - especially for people wanting a non-standard length or to save a little money. I'm hesitant to mention price because I don't want to flaunt the forum's rules on self promotion/advertising, but I also know that's one of the first things anyone who's interested is going to want to know. So I'll just say that I'm thinking in the neighborhood of $100 plus shipping, but if the moderators want to remove that (or any of this), please feel free.

That looks really nice Isaac! Given what Nauticam is charging for extensions these days that is extremely reasonable.

Edited 13 hours ago13 hr by Dave_Hicks

2 hours ago, Isaac Szabo said:

I suppose I should chime in here. I've had several requests for 3D printed extensions, so I recently went ahead and designed/tested an N100 version. I made the prototype 17.4mm, as I believe that is the reported length difference between the Sony 90mm and 100mm lenses (if anyone knows for sure the ideal length for the extension for the 100mm, please let me know). It's simple to do other lengths as well (it might be tough to do shorter than 15-16mm with the current design, though). It has a bayonet but not a port lock, though that shouldn't be an issue if you use a vacuum system. I tested it to over 100m.

Obviously, a 3D printed plastic extension is not nearly as nice as an aluminum one from Nauticam, but I just thought I'd let people know about this option - especially for people wanting a non-standard length or to save a little money. I'm hesitant to mention price because I don't want to flaunt the forum's rules on self promotion/advertising, but I also know that's one of the first things anyone who's interested is going to want to know. So I'll just say that I'm thinking in the neighborhood of $100 plus shipping, but if the moderators want to remove that (or any of this), please feel free.

Hi Isaac, really a nice try with 3D printing. Can you share more details about the material you were using, PETG or Nylon?

I'm in the market for a n85 16mm, I'm curious about material too.