Finally catching up on Underwater Photography Show episodes and got to the one about curved ports for wider macro shots.

In the comments, @Alex_Mustard mentions using the Sony 50mm with the Nauticam 4" port and a custom 16mm port extension.

Unfortunately the one he mentions has been discontinued. There is a N85 version available which should still work with the 50mm macro, but Nauticam's N100 to N85 adapter (which would have been perfect as its 20mm) has also been discontinued.

Are there any other options other than going fully custom?

5 hours ago, shokwaav said:

Finally catching up on Underwater Photography Show episodes and got to the one about curved ports for wider macro shots.

In the comments, @Alex_Mustard mentions using the Sony 50mm with the Nauticam 4" port and a custom 16mm port extension.

Unfortunately the one he mentions has been discontinued. There is a N85 version available which should still work with the 50mm macro, but Nauticam's N100 to N85 adapter (which would have been perfect as its 20mm) has also been discontinued.

Are there any other options other than going fully custom?

I believe you can still get the port but they are special order.

Have a look on UWVisions (Nauticam UK distributor) run by Dr Alex Tattershall and he maybe able to help.

I am looking at doing the exact same thing 👍

I have been testing the Sony 50 macro with a "curved port" (aka a dome port) using my A7RV and A7CR with the Nauticam N120 140mm dome. I estimated the EP at 43mm at infinity and 45mm at 1:4 (behind the dome it will be always focusing close because of the virtual image).

With a 25mm adapter (= extension), I calculated the alignment is almost perfect.

Land tests extol the IQ of the 50 macro, and criticise the slow AF. However, almost all available tests are using older Sony cameras, and there seems to be some improvement with the latest bodies.

There is no need to get the port mentioned, although it may be easier to light close-ups because of the small size. On the other hand, I have not seen a figure for the radius of this port, so we have no starting point to calculate the correct extension to best align the optical centre and the lens EP - and I believe you should always try to align a dome and lens as best you can.

I have posted results in other threads, but to recap:

Good:

Improvement in IQ (overall sharpness right across the image) is astonishing.

Not so good:

There are AF issues when using AFC with tracking and medium spot (my preferred setup for all my photography), presumably because of the 10 year old lens' primitive AF motor (compared to the latest zooms). The AF adjustments required when tracking focus on the VI are minute. But it is doable - if you give the camera a little extra time to "decide" it is in focus before you take the photo. You will still get the occasional failure - but nothing as bad as trying to use the MFO with Sony 90 with AFC and tracking - see the older MFO thread.

Next step is to go backwards and test AFS and AFC without tracking, and see how that compares. I would rather not, but I suppose it will be OK for subjects which are centre frame.

Even so, for general use I wouldn't go back to a flat port for this lens (only for the 90 - which I haven't got to work well behind a dome).

Minor update: I tested the 50 + 140 dome this morning in 3m viz, overcast and under a jetty, no focus light (must be worst case scenario).

Results:

Out of 28 images, there were about 5 focus fails. Subjects included seastars, a 30mm goby, and 40mm mid water fish (bullseyes).

I tried in order, all with medium spot: AFS, AFC no tracking, AFC tracking, AFS.

I found neither AFC setting was much good in the very dime light, depending on the subject contrast. If anything, AFC + tracking worked a little better than AFC no tracking.

However AFS worked quite well considering, although I would prefer not to centre the focus point (the eye for a fish) if I didn't have to (I'm not keen on focus and recompose with singe point AF).

I guess with my unpleasant MFO + 90 experience, with hindsight I should have tried AFS. However, that's not going to happen now.

In any case, shooting the 50 behind the dome cures the aberrations, so no need for MFO with normal focal length macro lenses...

For anyone thinking of buying a Sony 50, I suggest you try it out in a dim part of your camera store first, and see if it meets your needs. Or buy a used one so you can flog it if you don't like it, without losing money.

As for me, it's a keeper with the dome and some care with focusing. It's my go to rig if I want compact; otherwise it's the 20-70 with 180 dome.

There is a reference in the above video to the "curved port" macro style not necessarily suiting arty photos where you want to isolate the subject. Well, I'll take overall sharpness over fake bokeh any time. If I want shallow DOF, I'll open the aperture.

It's ironic really, when we don't worry about soft corners with macro, but we obsess over sharp corners with WA lenses!

On the subject of using a curved port for macro, clearly the port shown in the video is nowhere near correctly positioned at the centre of curvature and this is discussed in the video. The narrow angle of view of the Macro lens means the aberration from incorrect positioning as light towards the edge of the field is refracted is much smaller.

Clearly the mentioned port is going to be the easiest to use if you can get it special order. You would get similar results using something like the 4.33"dome port and appropriate extensions, but maybe not so easy to use? You would however need to buy one of the expensive N100-N120 converters as the dome is not available in N100. On the Nauticam #36471 n100-n85, the Nauticam website shows it in stock, though Backscatter says its discontinued.

1 hour ago, Chris Ross said:

On the subject of using a curved port for macro, clearly the port shown in the video is nowhere near correctly positioned at the centre of curvature and this is discussed in the video. The narrow angle of view of the Macro lens means the aberration from incorrect positioning as light towards the edge of the field is refracted is much smaller.

Clearly the mentioned port is going to be the easiest to use if you can get it special order. You would get similar results using something like the 4.33"dome port and appropriate extensions, but maybe not so easy to use? You would however need to buy one of the expensive N100-N120 converters as the dome is not available in N100. On the Nauticam #36471 n100-n85, the Nauticam website shows it in stock, though Backscatter says its discontinued.

Which curved port would be suitable for our Pana-Leica 45mm?

2 hours ago, Davide DB said:

Which curved port would be suitable for our Pana-Leica 45mm?

Probably the #36137 N85 4"wide angle dome port which they sell for the Olympus 9-18, 12-50 and Olympus/Panasonic 14-42 lenses. Seems like it is about as long as the flat port they sell for the Olympus 14-42 II lens. and 10mm longer the Pany 45 flat port.

1 hour ago, Chris Ross said:

Probably the #36137 N85 4"wide angle dome port which they sell for the Olympus 9-18, 12-50 and Olympus/Panasonic 14-42 lenses. Seems like it is about as long as the flat port they sell for the Olympus 14-42 II lens. and 10mm longer the Pany 45 flat port.

For video, I don't notice any issues with the edges, but it's a shame it's so expensive just to even try it out.

Edit: according to Alex, it's something more related to the Pana 30mm lens.

Edited May 23May 23 by Davide DB

6 hours ago, Chris Ross said:

On the Nauticam #36471 n100-n85, the Nauticam website shows it in stock, though Backscatter says its discontinued.

I tried ordering it directly from Nauticam who told me it was discontinued.

I managed to find two online stores who still have it in stock, and ordered from one, still waiting for it to get delivered. Then I'll try it with the #36137 4"dome port and see how well it works.

1 minute ago, shokwaav said:

I tried ordering it directly from Nauticam who told me it was discontinued.

I managed to find two online stores who still have it in stock, and ordered from one, still waiting for it to get delivered. Then I'll try it with the #36137 4"dome port and see how well it works.

Sounds great, though it's annoying a lot of these adapters etc. are being discontinued.

53 minutes ago, shokwaav said:

I tried ordering it directly from Nauticam who told me it was discontinued.

I managed to find two online stores who still have it in stock, and ordered from one, still waiting for it to get delivered. Then I'll try it with the #36137 4"dome port and see how well it works.

I found one used (as new) here in Italy at 295€ or best offer.

Maybe after the Alex's video they will choose to produce them again

38 minutes ago, Davide DB said:

Maybe after the Alex's video they will choose to produce them again

Well from my limited emails with Nauticam, they were very insistent that the N85 4" inch port was incompatible with the Sony 50mm 2.8 macro lens, and proceeded to suggest their recommendations from their port chart.

22 hours ago, Chris Ross said:

On the subject of using a curved port for macro, clearly the port shown in the video is nowhere near correctly positioned at the centre of curvature and this is discussed in the video. The narrow angle of view of the Macro lens means the aberration from incorrect positioning as light towards the edge of the field is refracted is much smaller.

Clearly the mentioned port is going to be the easiest to use if you can get it special order.

I agree that there is flexibility in aligning the lens EP and dome optical centre, but that's not a reason not to try. The video could have given us the radius of the "curved port" so we could draw our own conclusions - but it didn't.

By all means buy the special port, but why not first try your favourite macro lens with whatever "dome" you already have?

An advantage of the 140 dome is it can be used with many other lenses. Eg. the 140 + 25mm extension works fine with the Sigma 24 and 17. So I can go from macro to wide with no port change. Or I can add extensions if I want to use a lens with a longer EP like a zoom.

On 5/24/2025 at 12:52 PM, dentrock said:

I agree that there is flexibility in aligning the lens EP and dome optical centre, but that's not a reason not to try. The video could have given us the radius of the "curved port" so we could draw our own conclusions - but it didn't.

By all means buy the special port, but why not first try your favourite macro lens with whatever "dome" you already have?

An advantage of the 140 dome is it can be used with many other lenses. Eg. the 140 + 25mm extension works fine with the Sigma 24 and 17. So I can go from macro to wide with no port change. Or I can add extensions if I want to use a lens with a longer EP like a zoom.

Agree that there is no harm trying out existing domes you may have, however it also places the lens further from your subject, reducing available working distance and magnification, which is why I think the 4" macro port is favoured. It depends on what your targets are if this will present a problem or not.

My #36137 N85 4"wide angle dome port finally came in and big disappointment for Sony shooters - the 50mm macro can't fit in the N85 opening. Annoyingly, that's quite a bit of money down the drain.

EDIT: actually on closer inspection, I only need maybe less than a millimeter extra diameter for it to fit.... I'm wondering if I could widen it with something like a dremel...

Edited July 2Jul 2 by shokwaav

19 minutes ago, shokwaav said:

My #36137 N85 4"wide angle dome port finally came in and big disappointment for Sony shooters - the 50mm macro can't fit in the N85 opening. Annoyingly, that's quite a bit of money down the drain.

Could you use the N85-N120 adapter, and the Zen DP100 dome? So you can put the dome on after the lens gets put on from the front with the camera in the housing.

That's what I shoot with my Tokina and I'm guessing my 50mm Zeiss touit would also fit. I should try that.

18 minutes ago, Lewis88 said:

Could you use the N85-N120 adapter, and the Zen DP100 dome? So you can put the dome on after the lens gets put on from the front with the camera in the housing.

I'm actually on a N100 system, but I'm using the N85 4"wide angle port as Nauticam no longer make it in the N100 version.

On even further inspection, there's I think the focus ring is just a bit too wide, and there's also a small bump on the lens which is preventing the lens from going in.

You can see the little nub just underneath the label about the minimum focus distance.

Couple of things:

The Zeiss 50mm Touit is a better lens for APS-C than Sony 50 macro. Faster focusing, but you need A6400 or newer to get the best out of it. Make sure you get the updated firmware thru Zeiss (FOC) if you have the original V1. Otherwise it won't work properly with flash.

It also has internal focus and is narrower so will easy fit inside N85 accessories, so better in every way. Buy used (too expensive new).

Second point: I opened up a 36125 N85 port by approx 0.5mm to fit a Samyang 12mm. I used a cheap rotary sanding attachment in a drill press (has flip up bits of sanding paper, so good for sanding inside a tube). I packed the inside of the dome first with a rag. When finished, wash the dome carefully. Don't wipe with tissues!

41 minutes ago, dentrock said:

Second point: I opened up a 36125 N85 port by approx 0.5mm to fit a Samyang 12mm. I used a cheap rotary sanding attachment in a drill press (has flip up bits of sanding paper, so good for sanding inside a tube). I packed the inside of the dome first with a rag. When finished, wash the dome carefully. Don't wipe with tissues!

I'm considering doing either this, or taking apart the lens and removing the focus ring. Not sure which would be the easier solution!

On 5/26/2025 at 5:43 PM, Chris Ross said:

Agree that there is no harm trying out existing domes you may have, however it also places the lens further from your subject, reducing available working distance and magnification, which is why I think the 4" macro port is favoured. It depends on what your targets are if this will present a problem or not.

Out of curiosity, I compared the mounted dimensions of my 140 "curved port" + 25mm adapter, with as far as I can work out from the photos, the dimensions of the originally suggested N100 4" port #37122, plus the suggested 16mm extension.

There is nothing in it, meaning the 140 is just as compact (if not more so) than the 4" rig. Plus the 140 may be slightly easier to light (i.e. getting the strobes correctly positioned) for extreme close-ups, and it doesn't place the lens further from the subject (appears to be slightly closer).

So no need to chase the 4" port for normal FOV macro (say, 35 to 60mm).