All Activity

I share all of my designs and will post the Retra knobs soon. I am going to complete the set with a Power Level knob and will share them after a few more test dives. Can anyone share the height and diameter of the Pro Max knobs? I want to know if they are the same. Some of the older Retra models have smaller knobs.

I have the HF-1 and the Atom and will make those comparisons. Thanks for sharing your ideas for evaluating these similar strobes.

Hi and thanks for the welcome, @humu9679 !!!

PRICE DROP: £1850 + shipping

Does anyone have any experience with waterproof colour checkers? I'm looking for something that is accurate to industry standards (i.e. 'Macbeth' colorchecker, later manufactured by X-Rite, then Calibrite) but I have concerns about waterproof options. Keldan offer an X-Rite checker that is encased in resin (this one), but it is possibly too small for my intended use and I'm worried that the resin may interfere with the colour space. I've also only found it at £165.00. A company called gwbcolourcard offer a waterproof card for £27.99, but I've seen claims that they're not very accurate to the colour space due to the way they are printed rather than using solid pigments like the industry standards. Does anyone know about the accuracy of cheaper waterproof alternatives or the Keldan checker that uses resin? Alternatively, has anyone tried taking an accurate colour chart and laminating it yourself? Unfortunately I can't just go for a 'close enough' approach for colour correction because I'm looking into computer vision applications that will require accuracy. Any information would be much appreciated. Thanks, Henry

First, let me thank heartfelt all the testers, who do this thankless task of thoroughly testing and comparing strobes - so that we consumers have a clearer picture before acquiring the expensive equipment... Just my uninvolved remarks on strobe comparison: I fully agree that in any comparison with the new Retra Maxi, the HF-1 is very important to include. This is the reference strobe that Maxi was made to compete with... Another important strobe to compare with is the recent Retra top strobe (I think it is called the MaxII), since this is the strobe that top UW-photographers rate as the very best ones with respect to quality of the light (even distribution and color temperature). Not a direct competitor of Maxi or HF-1, but one would like to know what one is giving up, when acquiring the power models... Maybe also the new AOI P1 strobes is a strong competitor, it seems to be something in the middle between HF-1 and Retra Maxi (some people here wrote that the backscatter strobes are made by AOI; indeed the chassis looks very similar, but it has a circular tube like the maxi)... (I think that comparison of the Maxi with e.g. Z330 or even MF-3 does not make much sense - these strobes are in different niches)

???? N5 connectors/cables are yes, bulky, very bulky. However TTL is way much reliable and acurate... And in 30 years of UW Photography, i never ever had a single problem with N5 cables or bulkhead.... which is not the case with Fiber optic cables. Yet, i am using fiber optic cable today. With th exception of my Subtronic strobes... (that i use with 14mm or Fisheye lens)... without TTL. Funny

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.

Hi Dave, would you share the 3D/CAD files of the knobs. I also sometimes mix up the power and mode knob due to almost same design (only length is differnt). I was thinking to design a clip-on knop. But if your design solves also the "salt problem"👍😃. To be honest, I hadn't figured out the salt problem until today. Will later remove a knop on my strobe to get an idea how much salt stuck there. Br Markus

I've also got a N85 65mm port. Purchased incorrect port, never seen water.

This is an as new EMWL setup. It has been in the water a grand total of 3 times. It was not for me. All pieces are as new, no marks anywhere. Set includes (listed prices are new prices in USD without tax or shipping): Focus unit 1 for Nikon ($1,700) Relay Lens ($2,200) 130mm Objective ($2,100) 100mm Objecte ($1,700) Strobe Mount ($330) Total new is US$8,030 Will sell at over 25% off US$5,999 includes postage. Pay by PayPal I will cover fees. Will work with buyer to help with any duties.

This is a complete ready to go professional level underwater camera setup. Includes housing, camera, ports, lenses, torch, strobe and more. AU$12,500 / ~US$8,500 / Euro 7,300) The Nikon D850 is the last of the great DSLR cameras, still focuses quicker and more accurately than most modern mirrorless cameras. The housing and ports are SeaCam, still the Rolls Royces of Housings. This includes everything you need to just hit the water for both wide angle and macro photography and video. The step up includes (prices next to items are new price in Euro not selling price): SeaCam D850 Housing (5750) SeaCam Super Dome (2245) SeaCam Wide Port (1010) SeaCam Macro Port (~400) SeaCam 50mm Ext (325) SeaCam 25mm Ext (285) SeaCam 180 Sportsfinder (1750) SeaCam GPRO Finder (430) SeaCam Close-up Wet Diopter (~400) SeaCam Focus Gear for 105 Macto (265) SeaCam Zoom Gear for Tokina 10 - 17 (265) Nikon D850 (2900) Nikon AF 16 - 35 F4 (1200) Nikon AF 105 ED Macro (900) Tokina 10 - 17 Lens (~600) Sola 3200LM Wide Angle Torch (400) Retra Flash Pro (Only ~1,000 shots) (1100) Retra Flash Booster (200) Retra Fibre Optic Trigger (150) Fibre Optic Cables (~200) 2 x Strobe Arms (~200) 3 x clamps (~200) New this setup would be 21,000 Euro. Everything is in perfect working order. The glass on all lenses, ports and viewfinder is unmarked. The housing looks almost unused. The camera has a few marks from use but perfect working order. Lenses look almost new. Setting a realistic price: AU$12,500 (approx US$8,500 / E7,300) Pay by PayPal for protection. I will cover international postage and work with you for any import duties. Prefer to sell as a package, but will discuss different options.

Likely won't work if your strobe is like this one. Zero gap under the knob and i use a powerful electric blower after a some hours in the sink. The knob ought to have a little space to drain, even if a small hole or slot at the bottom. There is a considerable hollow under the knob that retains a CC or two of water.

Firstly thanks to Dave and Kiliii for the comprehensive reviews. On the question of salt, it seems to me it is very difficult to get rid of this salt in crevices etc. Just soaking won't do it, there's very little driving force to exchange fresh and salt water. On my previous Z240 strobes I would find salt crystals between in the space between the o-ring and the edge of the cap. Capillary forces hold the water in there and even after a 2hour soak or longer there's still salt there. If I change the batteries I can taste it, if I don't salt crystals eventually form. This is a problem on any small crevice, the gap between the two halves of the housing, buttons and control knobs, below caps like vacuum caps etc. At least with housing buttons you can press the button a few times to get salt water to leave, you can turn the knobs - but this doesn't do a lot I don't think. I have taken to blasting each control with with a blower bulb ( I use a Giotto rocket blower, surprisingly effective) , you can get a squirt of water out on all the housing buttons. I have Retra pure strobes, I aim the the nozzle at the base of each knob and the light button and blast till no more water comes out. I've just ordered a rechargeable air duster which I'll try out after next dive.

Aloha and welcome Wahrmut!

UWTechnics External TTL Converter for Sony installation in M24 hole on Sea&Sea MDX-aU housings:

Price lowered to $1550

Great review Kiliii! I think we are in sync on a lot of the details. I especially appreciate that the strobes you are comparing to are completely different than what I am using. I have Retra Maxi, Backscatter HF-1, Backscatter Atom. I don't have a Retra Pro Max-II, and I think that is an important point of comparison. Retra Maxi Control Ergonomics: I'll add one note here on the Retra ergonomics. The responsiveness and precision of the Retra Maxi controls are superb. Better than the Backscatter strobes for sure. The HF-1 power level knob is a crime against cold water divers. The Atom is better in that it's not simple round knob but a flat paddle, allowing your fingers to feel the position. However, it is smaller than I would like. While the Retra Maxi control precision is excellent, I don't like that the Mode Switch and Power Level look identical to each other. The power level is longer, but I found it hard to discern which was which. This is exacerbated when the strobes are in different orientations, resulting in mirrored positions. As seen below. I often shoot with one strobe up and one out on long arms. I can't see the backs of the strobes when in an inward position and my fingers have to do the all the work. Both control knobs fell the same resulting in mistakes that screw up settings. I love to customize the gear I use, so I addressed this with a custom made Retra Maxi mode switch knob. I find this design works a lot better for my style of shooting. It also fixes another issue with the Retra Knobs - salt deposits. The Retra knobs are completely flush to the back of the strobe and they have a internal voids that retain water. Even after a long soak and air blow dry, I will find salt encrusting the base of the knobs a day or two later. My design is essentially solid and leaves about a 1mm gap from the base, allowing the trapped salt water to be flushed out. I will probably make a custom Power Level knob that looks identical to the stock knob but leaves a gap to allow proper flushing of the salt deposits. (If you look closely, you can see salt around the base of Retra's power level knob even after I wiped most of it off)

Thanks for pointing this out. Excellent clip, as is his Part 2 on domes.

The awful Nikonos connector system (and cords generally) vs modern (wet) fibre optic systems...

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.

Hi everyone, I just did a pretty extensive review of the Retra Maxis compared to several other top of the line strobes, using quantitative methods in a studio. I reckon it's a good counterpart to Dave's review in the field here. https://blog.kiliii.com/underwater-strobe-shootout-marelux-apollo-iii-2-0-retra-maxi-seacam-160d-retra-pro-ii/ All of Dave's findings are echoed in my results as well, although I did come up with some big surprises when I did my controlled tests. The Retra Maxi is essentially a burst-shooting beast with a vastly better light quality than the Marelux Apollo III. And it does it at high power. Take a look!

Hi Michael, Thanx!!! Mehr und mehr ex-uwpixler... 😁 Hi @Landvogt1893 !

Hello and welcome :)