Folks,

I have two N85 Nauticam domes (4.33” & 6”) I would like to use on my Marelux housing for testing various smaller diameter travel lenses.  I have browsed around on the Marelux and Nauticam sites to see what extension adapters can be assembled to achieve this.  I believe it is possible, but would involve many pieces and be prohibitively expensive for testing.  Does anyone have any guidance on a different approach, or if there is a custom solution for a 5” Marelux to N85 Nauticam adapter possible?

Here’s an example Frankenstein option:

Marelux housing (5”)+ Marelux 31701 Extension ring 20 (Adapter for Nauticam ports) $200 + Nauticam N120 to N100 25mm adapter $360 + Nauticam 36741 N100 to N85 20MM adapter $420 + (4.33” or 6” N85 Nauticam domes I already have)

Thank you.

In principle I think it would be an easy adapter to make, an alumium disc about 6-8mm thick On the OD a lip at the top OD about 135mm stepping down to 125mm. In the middle an 85mm hole. The only tricky part working out how to mate with lugs on the housing and the dome ports and index them so that the port stays vertical and the dome shade is correctly aligned. You could potentially forego the lugs and rely on the vacuum to hold the pieces in places- just rotate the dome to the correct position. The pressure force acting to hold a 125mm (5") dome in place with 200 mbar vacuum is about 55 pounds.

If it was just for testing you could have a tab you could install from inside the housing to lock it in place if you wanted extra security. If it works out and you want to keep using then you could make lug rings you could bolt on the adapter later, similar to way Nauticam adds the rings to their ports. all this of course assumes you have access to a machine shop to do the need turning and machining.

7 hours ago, JayceeB said:

Does anyone have any guidance on a different approach, or if there is a custom solution for a 5” Marelux to N85 Nauticam adapter possible?

Another option: Try contact Saga. They have a lot of Frankenstein adapters on their site and I know for sure they make custom ports/adapters.

Marelux offers a 17mm N100 to Marelux port adapter for the WWL-1B and Nauticam has an N100 to N85 20mm port adapter which would theoretically work it you need more than 37mm of extension. This is an expensive solution v. just selling your ports and adding a

the Marelux 140mm fisheye port.

You may just want to ask which of the small lenses you intend to test have been used by others in the Marelux system.

SAGAdive.com may also be able to make a custom adapter bit at what cost.

Edited September 26Sep 26 by Phil Rudin

16 hours ago, Chris Ross said:

In principle I think it would be an easy adapter to make, an alumium disc about 6-8mm thick On the OD a lip at the top OD about 135mm stepping down to 125mm. In the middle an 85mm hole. The only tricky part working out how to mate with lugs on the housing and the dome ports and index them so that the port stays vertical and the dome shade is correctly aligned. You could potentially forego the lugs and rely on the vacuum to hold the pieces in places- just rotate the dome to the correct position. The pressure force acting to hold a 125mm (5") dome in place with 200 mbar vacuum is about 55 pounds.

If it was just for testing you could have a tab you could install from inside the housing to lock it in place if you wanted extra security. If it works out and you want to keep using then you could make lug rings you could bolt on the adapter later, similar to way Nauticam adds the rings to their ports. all this of course assumes you have access to a machine shop to do the need turning and machining.

Thank you for your DIY idea. I don't have access to a machine shop, but this approach gets me thinking in a different direction.

12 hours ago, Davide DB said:

ry contact Saga. They have a lot of Frankenstein adapters on their site

Looking now. Thank you for the resource. I was not aware Saga offered adapters.

1 hour ago, Phil Rudin said:

Marelux offers a 17mm N100 to Marelux port adapter for the WWL-1B and Nauticam has an N100 to N85 20mm port adapter which would theoretically work it you need more than 37mm of extension. This is an expensive solution v. just selling your ports and adding a

the Marelux 140mm fisheye port.

You may just want to ask which of the small lenses you intend to test have been used by others in the Marelux system.

Thank you for your response. I can't seem to find the 17mm adapter on the Marelux.co site though. I already have the 140mm fisheye port which I've tested with the Canon RF 50mm f1.8 with a +4 diopter. The results were pretty good, even with a cheap diopter. I have a better quality B&W diopter on order to see if that improves the sharpness. The acrylic 4.33" dome is even smaller then the 140mm dome and a fraction of the weight. The 50mm just clears the N85 diameter of the 4.33. I was looking at this as a light weight travel option. I have no idea how it will turn out, but I already had the 4.33" dome, so thought I would see if it was possible.

1 hour ago, JayceeB said:

Thank you for your response. I can't seem to find the 17mm adapter on the Marelux.co site though. I already have the 140mm fisheye port which I've tested with the Canon RF 50mm f1.8 with a +4 diopter. The results were pretty good, even with a cheap diopter. I have a better quality B&W diopter on order to see if that improves the sharpness. The acrylic 4.33" dome is even smaller then the 140mm dome and a fraction of the weight. The 50mm just clears the N85 diameter of the 4.33. I was looking at this as a light weight travel option. I have no idea how it will turn out, but I already had the 4.33" dome, so thought I would see if it was possible.

I don't see the RF 50mm F/1.8 listed on the Marelux or Nauticam port charts only the RF 50mm F/1.2 on Marelux behind a 67mm flat port. How are you using the 140mm port with an extension or direct mounted? Could you perhaps improve sharpness with better dome placement? You also may want to consider that looking through a five inch opening prevents vignetting while looking through 85mm's with extensions/port adapter may result in vignetting. The best case Sanrio for a five inch to 85mm adapter would I suspect push the port out at least 20 to 25mm.

15 minutes ago, Phil Rudin said:

I don't see the RF 50mm F/1.8 listed on the Marelux or Nauticam port charts only the RF 50mm F/1.2 on Marelux behind a 67mm flat port. How are you using the 140mm port with an extension or direct mounted? Could you perhaps improve sharpness with better dome placement? You also may want to consider that looking through a five inch opening prevents vignetting while looking through 85mm's with extensions/port adapter may result in vignetting. The best case Sanrio for a five inch to 85mm adapter would I suspect push the port out at least 20 to 25mm.

I tried the RF 50mm F1.8 on my own after contacting Marelux. They mentioned it should work with the 140mm mounted directly although they had not specifically tested this configuration. I did not test any additional extensions to improve sharpness, but I could (with my limited extension quiver)

I did not consider the risk of vignetting when pushing the N85 out further due to extensions. Thanks for pointing that out. I'll try estimating by holding the dome manually out in front of the lens to get a ballpark idea.

By the way the N100 to MX 17mm is available at Marelux, it was spicificley designer for the WWL-1B at the request of a client.

It worked well and adds a bit of extra AOV v. the Nauticam 45mm port recommended with Sony 28-60mm zoom. I tested both.

I will be selling the 17mm adapter since I have moved on to the Marelux Aquista 120 & 100. The WWL-1B went down the road over a year ago.

Have you considered the 50mm behind a flat port?

I initially considered the 50mm behind a flat port. I tried my RF 100 macro port to see if that would work, but there was severe vignetting. Given I was in test mode, I wasn't ready to purchase any additional macro or extension ports.

I think the port placement for the 50mm lens going to be less critical than a wide angle lens, so if it works in the 140mm dome maybe stop there?. On the topic of ports, not sure if you already have the Marelux N120 adapter, the Nauticam N120 4.33" dome may be a good solution if you do, relatively expensive new, but second hand might an option?