Adventurer

Wow, that's actually great news! .. for me as a user / potential buyer to finally see some quick competition catching up. We need more companies to break the Nauticam uw lens monopoly. If it's coming at a reasonable price, I'll probably order one from Hydronalin.

It's very ironic that you start to discuss about corner sharpness performance of a lens that does not project corners at all to the sensor 🤣 😂 ... But I am 100% with WASO and would love to see some RAW files with that lens + WWL-C.

After some research I found Nauticam was the only company to make an Nikonos V Adapter so far. There seem to be 3 iterations of it: N-85 / APS-C: # 3601 the first Nikonos 15mm Adapter, was made for SONY NEX-5 N-100 / FULL FRAME: Version One # 37201 N-100 / FULL FRAME: Version Two # 37202 ( which is described in this PDF manual ) Version One is reffered to, to be working with Sony A7 on some Nauticam dealer websites, whereas version two is supposed to be working with A7II onwards. The official Nauticam page says A7II / A9 / A7RIII / A7RIV / a2020 / A7C as of January 2026. It would support the different flange distances measures by some Nauticam Sony owners and explain why there are two versions and why some owners hat to modify their camera tray to get the lens working sharply. Does anybody know more detailed differences between the Version One and Two for FullFrame N100 ? I have attached images of all three variations below.

Thanks so much for the detailed breakdown, Alex — that’s exactly the kind of reality check people rarely hear, and it’s incredibly helpful. This line especially jumped out at me: I suspect that “15% zone” is the part most photographers are most curious about — not because we want loopholes, but because it’s where the work becomes visibly transformative while still being completely legitimate. And it’s also where a lot of the confusion (and insecurity) tends to live. Also, there are images where “noticeable processing” isn’t just optional polish, but part of what makes the photograph possible at all — provided it’s within the rules and properly declared. Things like HDR, stitches, and panoramas come to mind. A great example is the kind of wreck panorama work Tobi has produced in past years. That sort of result simply doesn’t happen without deliberate, skilled post work (and usually a pile of source frames). Which leads me to a cheeky follow-up wish: if Tobi is literally with you right now as an interview guest for the show, could you grab him before he flies back to Germany and persuade him to do a “behind the curtain” walkthrough of one of those stitched wreck panoramas? Seeing the RAWs/source frames and how the final panorama is assembled (and then what the contest-specific “acceptable limits” look like around that) would be absolutely gold. For example, something along these lines is exactly the kind of image that would make people go “wait… how is this allowed?” and then learn something genuinely useful: And good luck (and strong coffee) for the UPY 2026 RAW-check marathon — hoping for zero surprises and maximum honesty from everyone entering. Warmly, a grateful viewer

Dear Alex and Matthew, I just watched this episode and wanted to send a proper thank you (and also file a formal complaint, because you’ve made me feel oddly relaxed about competition submissions): The Underwater Photography Show - How We Process Our Underwater Photos: Seriously—thank you. You tackled the RAW-check topic in a way that didn’t feel like a courtroom drama, but also didn’t hide behind “trust us, it’s fine.” For the first time in a long time, a chunk of my contest anxiety quietly left the building. 🫠 For context: I’ve definitely done the two classic, equally ridiculous things that happen when confidence is low and the “invisible line” is unclear. On one end, I’ve submitted images almost untouched because I thought, “well, at least nobody can accuse me of anything.” Genius move - like entering a cooking contest with raw potatoes. On the other end, I’ve also gone full mad scientist in post because the line in my head kept moving, and I didn’t know what a jury would still consider reasonable. Your episode didn’t just explain the why; it cleared the fog. Now, since you’ve already built a perfectly good stage and proven you can talk about sensitive stuff without setting the internet on fire, I have a wish episode request-selfish, yes, but I suspect a lot of underwater photographers would binge it immediately. Could you do a special where a few brave souls (say, 3-6 volunteer UPY winners or past finalists) show their unprocessed RAW, then the final, and walk through what they actually did? Not in a “hand over the sacred secrets” way - more in a “here’s what a real, jury-safe workflow looks like when it’s done by someone who knows what they’re doing” way. Something that turns the abstract “how much editing is acceptable?” into concrete, visible examples. And if you ever feel like going full premium content: a second episode concept I’d call “Winners & Sinners” (said with love). Imagine one to three extremely confident underwater photographers volunteering for a constructive post-mortem with Alex in juror mode: why something failed the RAW check, or why the RAW check might have pushed it off the top spot. Done with full consent, with a genuinely educational tone, and with the kind of humour and care you two already bring - so it’s never a public shaming exercise, just a rare look behind the curtain. Alex, timing-wise, this might be a perfect one to record fairly soon while your judging impressions are still fresh. But to avoid any weirdness, speculation, or accidental comment-section chaos, you could feature images from earlier UPY years rather than the most recent winners - so nobody turns it into “this is about this year’s results,” and it stays purely about learning. I know it’s sensitive territory. But that’s exactly why it would be so valuable. The uncertainty is what makes people do silly things - like submitting totally unprocessed files out of fear, or editing until the pixels start writing resignation letters. A calm, example-based, behind-the-scenes look - done in your style - be wildly helpful and genuinely inspiring. Anyway: thank you again for the episode. You didn’t just explain RAW checks - you cured a little bit of the underwater photography community’s collective overthinking. Which, if you ask me, deserves at least a small trophy and a dramatic stingray fanfare. Warmly, a grateful viewer

Thank you, but can you confirm that you are using a Nikonos III Version 15mm lens in the same adapter as the Nikonos V 15mm ? I am in doubt that this is possible. I had to put the project aside in frustration, for the following reasons: The Nikon Z Mount has a Flange Distance of 16mm, the Canon RF Mount has a Flange Distance of 20mm, and the Sony E Mount has a Flange Distance of 18mm. Sony E Mount = 18 mm Nikon Z Mount = 16 mm ( -2mm ) Canon RF Mount = 20 mm ( +2 mm ) A Nauticam Full Frame Nikonos Adapter exists for Sony N100 Nauticam Sony (N100) Flange Distance = 28 mm * Marelux Canon Flange Distance = 51 mm ( + 23 mm ) * Nauticam Sony N100 flange distance has strangely been reported with 3 different measurements (by owners) in this forum: 28 mm, 27mm and 26mm . Hence, for getting a Sony N100 Nikonos adapter to work inside a Marelux Canon housing it would need to move 25mm, or even 28mm inwards, depending what customer measurement you trust. This seems nearly impossible with the knobs on the side, as the Nikonos II 15mm lens has a diameter to aperture + focus knob of 132 mm. Furthermore my flange distance Google research / Wikipedia Germany claims that: Wiki Nikonos Flange = 28.00 mm vs. Google AI pulls of = 46.50 mm ..but I measured the following flange on my Nikonos III camera * * I put the camera in B (bulb mode) and pressed the shutter to really reach down to film plane behind the shutter with a calliper lower silver contact: 32 mm upper silver lip: 39 mm ( + 7 mm ) not matching any of the two web-researched infos above. Can anybody confirm that the Nikonos II cameras flange distance is different from Nikonos V series ?

No, you should definitely not accept that and keep in mind what Alex said: I think several of us here, especially Alex and Matthew have experienced more than 2K or high definition in their digital underwater photos, even when taking pictures behind a dome port. It highly depends on your prudeness with port positioning and and dome size selection. .. maybe you can pass him a visit at look at the humongous amount of Nikonos glass he is hoarding 🤪 ( https://achtel.com/nikonos-lenses/ ) which makes me pack my bags and want to move to Australia, instantly! *Alex and Matthew own the "holy grail" (adapted Nikonos RS13 Fisheye) and a (hopefully well positioned) 8-15 fisheyes behind domes and may comment / judge their personal perceived resolution advantage. Alex on top may also compare it to his Ivanoff Zeiss 20mm experience and the Nikonos V 15mm lens on a full frame.

Well it turns out, that this is very unlikely to be a problem when searching the sharpest knives (lenses) for underwater imaging. As @Chris Ross 's linked blog post and @Alex_Mustard 's Admiral Achtel's thoughs brought up the optical Nyquist limit I dove a little deeper into the physics and technical aspects behind it. For Chris's concern,... if we look at MTF50 charts only, not MTF10/MTF20, the results are indeed quite comparable with a potential offset between 0% and -15%. We can keep this in the corner of our head. IMPORTANT: the Nyquist limit is raging against Diffraction Airy disc limit. Diffraction kicks in earlier then Nyquist limit, forcing you to use more conservative F-Stops. But it is very handy to know what might define the true optical theoretical ceiling with various full frame cameras in 2026. For example my Canon R6 II will most likely not resolve lenses that excel beyond 83.33 lp/mm - and your Canon R5 II or Sony A1 II will most likely not suck out much more than that, as you will kill IQ earlier with diffraction. I compiled the following handy table for your reference:

Unfortunately we are drifting away in this thread with a lot of speculation, hairsplitting and nothing new brought to the table by some contributors. This was not what I wanted in the topic opener. I want lens pitches ( „potentials“ ) which we can explore and test AND quantifiable (lp/mm and LW/PH) to get an idea where they possibly stand. These of course have to be ranked in separate lists for each camera brand bayonet and are not cross comparable. It‘s also problematic if you compare testing website source A with website B or have to compare underwater or topside values. But you have to start somewhere to get a vague idea on what’s possible. Also I think it‘s important to relate to something you know. Many of us have the EF 8-15 (or an RF100) and can therefore relate to how pixelpeeping a 54 lp/mm (or 86,5 lp/mm) candidate looks like.

Thanks for this Link! Surprisingly, this puts the “legendary” Nikonos V / UW-Nikkor 15mm at about 51.9 lp/mm, i.e. below the RF 100mm and closer to EF 8–15mm land performance — and here’s why: 1) The test is not full frame (crop factor first, and it also explains the reduced underwater FOV) The Wetpixel/Achtel measurements were done on a RED EPIC MYSTERIUM-X (Super-35) recorded in 5K 2:1 (5120×2560). In that mode the active imaging area is roughly 27.65 × 13.83 mm, which is about a 1.40× diagonal crop compared to 36×24 mm full frame. That crop factor directly explains why the underwater diagonal FOV quoted for the Nikonos 15mm looks “reduced”: the UW-Nikkor 15mm is specified around ~94° diagonal underwater, and applying ~1.40× crop gives roughly ~75°, consistent with the ~74° figure discussed in this context. So this is primarily a format/crop effect, not the lens “getting narrower” underwater. 2) Why an “edge” Imatest ROI on this setup is not a full-frame corner If Imatest samples an edge/ROI near the edge of the RED frame, that location maps to about 1 / 1.40 ≈ 0.71 of the full-frame image radius. In other words: it corresponds to mid-to-outer field on full frame, not an extreme 36×24 corner. So the Imatest result should not be interpreted as “full-frame corner performance.” 3) The lp/mm number is a derived value (LW/PH → lp/mm conversion) Imatest reports MTF50 in LW/PH (line widths per picture height). To convert to lp/mm on the sensor plane: lp/mm = (LW/PH) / (2 × picture height in mm) For RED 5K 2:1, picture height is ~13.83 mm. With the reported MTF50 ≈ 1434 LW/PH: lp/mm = 1434 / (2 × 13.83) = 1434 / 27.66 ≈ 51.9 lp/mm Bottom line: the widely quoted ~51.9 lp/mm is a converted sensor-plane MTF50 number on a cropped Super-35 capture, and the sampled field position is closer to mid/outer field than a true full-frame corner. As the values I initially posted for comparison were also center / near center based performance values in lp/mm we can use this for comparison. We should however honor the high open aperture resolution performance of the Nikonos V 15mm while keeping the dismal flexibility and manual focussing required underwater in mind when judging the practicability.

If you look at the entrance pupil position, of the Canon EF 8-15 everybody in this forum who used and tested the small Nauticam and Marelux (approx 140 diameter) dome is suffering from a mis-positioned lens. Both these domes are not full spheres. They are missing a tiny bit and the ball is not exactly cut in half. Due to that it‘s recommended to shoot them at minimum F16 or smaller aperture values. If you want to max out the IQ and archive „superposition“ you have to die the death of vignetting and combine it with a 2.0x TC and in most cases you will also have to remove the sunshade of the dome underwater and use it from approx 18mm to 20mm focal length onwards. With my MARELUX and small dome this wil require 85mm of extension rings. Vignetting disappears from 18mm onwards.

Welcome, Tia — two quick thoughts that may help: There’s a must-read thread on corner sharpness with the Canon 8–15 fisheye. The author questions the Nauticam port chart and also ran extensive Nauticam port tests. It includes a simple “at home” position test you can do to confirm whether the lens is sitting at the correct position in the dome: https://waterpixels.net/forums/topic/1438-testing-nauticam-n120-port-extension-for-140mm-and-180mm-domes-with-wide-angle-lenses/ Even if everything is set up correctly, you can still run into depth-of-field limitations underwater (similar to what you’re seeing on land). Your sample image might be a good example of that. Former forum member Interceptor121 has a very good write-up on this, and he repeatedly notes that placing your focus point closer to the corners of the frame can help improve corner sharpness: https://interceptor121.com/2023/03/18/canon-8-15mm-with-kenko-1-4-teleconverter/

Nope - or did you mean it the other way round and this was a typo? I guess you fell in the common trap that prices in the EU are only allowed to be advertised incl. VAT, while online advertised prices in the USA excl. VAT.

Definitely buy yourself the EF-RF Adapter from Canon. There is so much you want to transfer into your new system! For example the Canon EF8-15 a very important valuable lens. You may even easily cross over from Nauticam to Marelux, as they offer Nauticam port adapters.

„The dial“ is also available on your Marelux housing. It will be your Aperture, Shutter Speed or ISO dial, depending on your R6M2 configuration. The arrow keys do the same thing as they do, when you push the touchpad of your camera when not installed in the housing 😉