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 5 hours ago5 hr 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.