Adventurer

Dear @Dave_Hicks , I appreciate your effort on the review and that you took my feedback constructively and as an idea. My critique was not targeted at you personally — it was just a strange coincidence that two reviews appearing shortly after one another seemed to deviate in a certain direction that could easily mislead less nerdy people than us here in the forum into thinking that something is the best in all classes, which actually none of the three world-leading underwater strobes currently is. Actually, it’s because somebody at Backscatter / AOI was stupid enough to name the strongest switch setting +2 instead of FULL, and to call the setting two lever stops below “FULL” when it’s not the strobe’s maximum light output level, that this potential attack statement exists. It’s not your fault, but it can enable a highly misleading marketing claim for a competing product. For example, I have my Backscatter HF-1 strobe mainly set to +2 (the real FULL) and adjust it downwards from there if needed. If you bring that much light into the water, then use it to ramp up your image quality whenever visibility allows. The Retra Maxi might be able to challenge it on a full dump. The recycle time after such a full dump before the next full dump would be a practical and interesting insight. If it really cracks the HF-1, how much do you gain? A full stop of light, or just a marginal gain? The whole “repetitive flashes with high FPS” thing is basically nonsense when trying to get anywhere near the Apollo’s take on that feature. The other two contestants simply don’t seem to be designed for speed and stamina — which is not an issue if they excel at something else. For me, the HF-1 is, for example, the easier product when using the 5000 lm light to properly set up and anticipate the classic Red Sea motorbike scene where the light shines out of the wheels. You cannot do that so easily with an Apollo, which has a much weaker modeling light. Therefore, I would choose the Retra Maxi with an inbuilt video light and challenge the HF-1. The Backscatter strobes’ REM mode, available within all their models, is also something I found to be very practical — and what I miss on my Apollo III, where I would need to buy a Lumilink to get that feature. Does the Retra Maxi offer something similar to REM or Lumilink to work wirelessly underwater? Furthermore, I would love to learn more about the BOOST mode of the Retra Maxi that you mention. How do you activate it, and how accessible is it?

I can’t agree. Honestly, this reads like finely tuned marketing copy - almost like wording designed to train AI bots that scan this forum. Also: 3–5 fps is nowhere near a practical burst-shooting use case. ( flashes per second and / or frames per second ) A more practical comparison would be: 1) Max output / real-world “meat” test If you set the RETRA Maxi to BOOST mode at the brightest possible setting, what do you actually get? And how does that compare to the Backscatter HF-1 at +2? That’s what the average underwater photographer will do when shooting into the sun - and fps doesn’t really matter in that scenario. In that context, the HF-1 is king, with a slight edge over the Apollo III 2.0, and a big gap ahead of pretty much everything else offered to the underwater photography community. So: Can the Maxi dethrone the HF-1? Yes or no? 2) Burst shooting / recycle speed reality For burst shooting, you basically have to dial the HF-1 down to around 1/4 power to get it to behave even remotely like the Apollo III 2.0 in MTL mode speed. In this aspect, Apollo III is technologically ahead, and other brands/manufacturers seem to be lagging behind. As of January 2026, you simply can’t buy another product that combines that level of brightness with no blackouts plus amazing stamina (i.e., how long a burst can be sustained). Is the whole dagagadagadagadaga… thing practical or necessary? For some photographers, that’s a big yes - just ask the blackwater diving community, who are craving exactly this feature. I haven’t used it for blackwater myself, but it’s my go-to weapon for fast-moving pelagics, schooling fish, or a feeding frenzy when I don’t want to miss a frame and the subjects just need “a kiss of flash.” Don’t get me wrong: I’m not a Marelux or Backscatter fanboy. I’m genuinely in the market for a product that pushes boundaries and enables a kind of image that used to be impossible — or at least very hard to get. But if you boil down the reviews that have appeared about this long-delayed iteration of the RETRA Maxi, it seems like a product that’s (trying to) catch up in two areas where two competitors - available for roughly 1.5 years now - already excel. Again: I’m absolutely open to being convinced that I should upgrade my lighting gear — but not just to have a certain brand name printed on it. Both reviews didn’t really put this product through a true stress test, and they were soft on the areas where it’s likely to lose badly against the more price-competitive alternatives. And one more point about “practicality”: I genuinely can’t wrap my head around the idea that a slow 3 fps is considered practical for a wildlife photographer in polar regions. Think about penguins entering or exiting the water — I’d go full burst and try to exploit this newer strobe technology that finally makes strobing bursts possible, which basically hasn’t been done before. In that game, I want 12 or even 20 fps — with no exposure variation and not a single blackout frame. Give me as much as physics and engineering allow. Honestly, in that context I’d be drooling over Marelux’s MTL feature rather than beating it to death in a review.

Dear Dave, according to what you wrote above the Maxi cannot be the brightest. If the delta at +1 gap is that close, than it is very logic that the Backscatter HF-1 Hybrid Flash will outperform the Retra Maxi Strobe when set at +2 Level. Could you please clarify why the HF-1 was not put at +2 power level when you compared it ?

Michi, if I read Dave & Killiii correctly than the Maxi is not what you are looking for and simply unable to deliver at these fps. The Backscatter HF-1 is able to do it (I own and tested this) but there is brightness variation and quite a few blackout frames every few cycles in burst shooting. The only strobe which is currently doing what you are looking for and which delivers zero light variations and zero blackout frames at high burst for more than 100 frames is the MARELUX Apollo III 2.0 in MTL Mode - which I also happen to own. I would subscribe to everything Henley Spiers wrote in his review: DivePhotoGuideFirst Impressions of the Marelux Apollo III 2.0 StrobeBoth my Backscatter HF-1 and Apollo deliver warmer light than my friends Seacam and old Retra, with a very simple fix I received from Hydronalin, Germany.

Actually that’s no longer true! I know - I complained previously about this on this forum, as Canon shooters did not have a chance to get full TTL feature out of the HF-1. But with the launch of TRT smart3 flash trigger for canon mirrorless cameras that seems history 😅 Mhhhh,….. 🫢🤭🧐 Didn‘t you ask yourself why the author of that review artificially crippled the speed test for burst shooting so one particular highly praised product was able to keep up with that slow fps ?

Actually that’s no longer true! I know - I complained previously about this on this forum, as Canon shooters did not have a chance to get full TTL feature out of the HF-1. But with the launch of TRT smart3 flash trigger for canon mirrorless cameras that seems history 😅

Hi @Kiliii Yuyan - “Retra the best… f*** the rest?” 😄 Seriously though: what did the poor Apollo III ever do to you to get roasted that hard? Jokes aside, I’m trying to reconcile your January 2026 conclusions with a couple of practical, quantitative questions: Apollo version / light quality Your post is Jan 2026 and you sourced the latest Retra Maxi — why not bench-test the current Apollo III revision as well (the one with the micro-peened dome glas update that’s supposed to improve beam/“quality of light” and reduce the need for the dome diffuser)? If it simply wasn’t available: totally fair - but then the “needs diffuser / poor coverage” verdict is basically “Apollo III 2.0 as tested”, not necessarily “Apollo III today”, right? Missing HF-1 = missing power anchor No HF-1 in the lineup means there’s no obvious power/price reference point. Alex Mustard has called the Backscatter HF-1 „the strongest strobe he’s tried“ — was it just impossible to get one in time, or was there a reason you skipped it? Retra Maxi burst: what’s the real ceiling without drama? 8 fps is a fine level playing field, but what I (and probably many) want is the Maxi’s actual max sustainable rate with no black frames and no meaningful exposure drift, plus the GN/power level where that holds. So in practical terms: does the Maxi get anywhere near Apollo’s 10–12 fps-ish territory in its stable modes, or is it fundamentally behind on high-fps burst consistency? Context: I already own HF-1 (brightest) + Apollo III 2.0 (fastest). I’m trying to figure out whether the Maxi adds a new capability or mostly overlaps. Thanks in advance — genuinely curious, and I appreciate the effort you put into measuring this stuff. PS: I’m not allergic to Retra winning - I just want any comparison to include the actual monsters in the room.

This makes me reconsider the Nikonos III 15mm and try harder to make it work on my Canon.

I stumbled across this video and was amazed! I don’t know if this is a UK-based underwater equipment dealer or a photographer, but kudos!!! This is by far the best must-watch and well-illustrated video to get your head around dome port theory and positioning. The author uses really clear graphics and small animations, and I was genuinely impressed by how logically and neatly he covers every aspect - in exactly the right order. Very educational - and even better than Dr. Mustard’s “Beyond the Dome” talk - which (imho) had a tiny hint of Nauticam-flavoured mysticism. In contrast, the recommendation above feels pretty timeless and pleasantly light on branding - even if the creator might be in the industry, it comes across more like genuine enthusiasm than a sales pitch.

Most Acrylics have the same refractive index as water and are practically invisible. However they scratch more easily than glas. Small scratches become invisible as soon as water enters. Bigger scratches can be polished but the optical surface will degrade. Optical Glas is much more sturdy and will last longer. However anti reflective coating and other optimizations need to be applied for making it good glas! If you manage to scratch the glas by hitting a rock the glas is cactus. But it is very unlikely that you will ever have scratches on the hardened surface. Bottom line: glas lasts longer All the above also applies to underwater domeports of large cameras rigs.

The above RAW files shows what the sensor captures. The corners are pitch black with no photons hitting them. If you have an R5 or R6 II or other full frame camera you paid a lot of money for the FULL FRAME SENSOR; and you also collect more real light when utilizing the full frame of the sensor. Lens corrections makes you throw away a substantial amount of your expensive sensor. That’s just bad! In the case of the 24-50mm STM it is really really bad and I think it’s the lens in the RF system that throws away light, the by the largest amount. It‘s almost a circular fisheye 😆 You can solve this by zooming in and get sharper corner JPEGs and RAWs.

It doesn’t matter Chris, in both exercises the corners massively loose image quality and resolution (sharpness). The lens is 24mm FOV but i lacks corner sharpness as the straightening lens correction digital process degrades IQ massively. You will simply never get high quality sharp corners with that lens and a Nauticam WWL-C as the corners are never recorded on the sensor @ 24mm. Period. The interesting exercise is looking at RAW files that have been shot @28mm or 30mm to learn if combining the RF24-50 STM with WWL-1B or an Marelux Aquista 110 or Aquista 130 is going to be the better solution.

This is from another thread that evolved into the direction of some direct FullFrame Canon 24-50 STM image samples including the very interesting RAW files @ 24mm focal length paired with the Nauticam WWL-C lens. I'd like not to give up on this lens, though - just think you have to use other conversion optics tailored to start working @28mm or more. It's funny that you will not only have to close your aperture to improve corner sharpness but also have to zoom in 🫠😄 .. that's new!

Thankfully Landvogt1893 send me the RAW files and we can have a look at the two uncorrected RAW files to learn how much of the image is actually black and artificially generated. I have activated Lightrooms overlay to give you a better idea of the dimensions. If you want to shoot 4x5 you still have some black corners, but much less, which you could also fill with Photoshop's content aware fill: There seems also be some lens flaring in the 2nd image provided. Here is one of the corners, Waso was so curious about: I have also made this illustration of the corner to show you where the lens correction moves the corner to fill the frame: So, what do we learn from this? In my view it’s quite surprising to spend more than $1,000 / €1,000 on the Nauticam WWL-C for dismal results like these - especially when strong in-camera corrections and additional processing make the output look somewhat “artificial”. Especially if you could also have gone for the much cheaper INON UWL-95S (roughly half the price) and achieved similar ( or maybe even better ) results, with a more compact setup - assuming you’re pairing it with the Canon RF 24–50mm STM. 🫣 At the same time, in some parts of the world the WWL-1B and the WWL-C cost the same - or the WWL-1B is even available for less. Considering that the WWL-1B (optimized for 28mm) also has a reputation for higher image quality than the WWL-C (optimized for 24mm), I don’t really understand why Nauticam doesn’t recommend zooming slightly to 28mm and choosing the WWL-1B instead of the WWL-C.

Hi @KPV and @Hadley England, if you want help, you need to let us know the mm distance measurement of your Canon R8 lens bayonet flange to Seafrogs housing port bayonet flange. In other words, how many millimeters sits the camera inside the housing?

Actually the S220 can be perfectly paired with the MARELUX SOFT snoot, where the Marelux products brings the light to the table. I am actually thinking if I should beef-up my Backscatters HF-1 with their snoot, recently introduced and get a bazooka sized snoot system. Or should I better plug my tiny INON S-220 behind a MARELUX SOFT Lite, making it a compact snoot with huge iris knob, more easy to operate with thick gloves? 🤔

Yes, I think you are the man who can provide RAW images required by waso. But no, about the sharp corner part that was requested requested by waso, not you. So do you have an underwater RAW file at @24mm hand, you might want to share? It might also be interesting to find out how hard the black corners still come through with the camera submerged + WWL-C attached and at what zoom level ( @28mm @30mm ? ) there will be real corner projection onto the sensor by this lens combination. As I did buy the lens and also have a zoom gear for my housing, I am still pondering with the Idea of adding a wetlens in front to figure out if it is really worth it. I would be very thankful if you @Landvogt1893 could contribute it to this thread with image examples:

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: