Adventurer

@Chris Ross it depresses me how you communicate here in public, obviously just for writing the 180 degree counter argument to what I contributed here. How should I have missed the point? Can we please leave personal grudge aside? I am obviously going to loose this against a person with moderator status who seems to own this forum. My point and remark was, that in the promotional write-up from the ikelite blog, there are nice images, yes. But the underwater photographer Steve Miller has obviously cropped and processed his shots. Just a few are still in 3:2 - so he may have cropped where the sharpness is splendid, to make the images look nice. A lot of the photos have also extremely darkened corners. It makes the images look interesting but gives full frame users no clue, how many pixels they have to throw away of each shot to get a sharp piece. And the curvature IS NOT 80mm behind the entrance pupil on the 8" ikelite dome. An extension of approx 43mm will get you to the NPP of the Canon EF 8-15 fisheye lens. As I have done some more chessfield testing in the bathtub yesterday, I can tell you that also the Fisheye is not invincible when it comes to dome abuse and mis-positioning. Have a read here:

Well with the frequency at which new products enter the market this year your current converter might already be outdated once it arrives from Taiwan with you and you are drooling at the next new strobe that just was announced. So online updating would be highly appreciated over importing and exporting physical goods which will easily eat up $100++ for one round trip shipment.

I am totally with you, Isaac. But as the original intention of this thread was to build an excel sheet that readers might take for granted I would suggest to abandon that mission. The case illustrates: You simply do not know how accurate your volunteering data donors are at measuring and reading the results.

Quite evil post @Barmaglot ?!?! Have you had bad experience with them or are you even affiliated with an INON competitor ? That you can pull off guide numbers beyond 40 out of compact 4xAA design has been successfully demonstrated by Canon EX Speedlites more than a decade ago. Canon 580EX II had GN = 58 Design has further progressed to shrink size and level up to GN60 in compact designs, this is @ 200mm focal length, with Canon Speedlite EL-1 though. But looking at the available water cooling and INONs advanced experience in underwater reflector design, crossing the GN40 barrier in year 2025 sounds quite archivable to me; even if you have to deliver a wider beam.

KickAss question 👌 - RETRA UWT shows that it should be possible to communicate with your underwater lighting product via Bluetooth in the 21st century. Turtle TRT at least delivers updates and configurations via USB connections and Apples App Store. Wireless Update Distribution would save us all from a lot of headaches a shipping cost frustration. 🙏

Friends told me which have seen the prototype on a trade show that INON is heading to be part of the beyond Guide Number 40 club with that strobe. In fact way beyond: aiming at the GN44 / GN45 region. All this while maintaining the 4x Eneloop design and small size and weight of a Z330 body. This would be very travel friendly and amazing advance in electronics efficiency. 😎 exiting times!

Well, a +4 diopter should not break the bank and also add less than 30 gramms to your travel weight. As long as you do plan on doing splits (over under shots) the diopter will make your lens AF much faster, as the virtual image never appears at infinity when the dome is dipped in water. It will pull the AF to a working area that is more likely to happen underwater. Having said that, you may also improve your RF 14-35 with a minor diopter when working behind more compact domes.

No, we certainly do not agree to this. I have not seen an an led torch which was able to out-compete strobes (even when they are in HSS mode). And I have seen and used 20.000 lumen video lights validated in an Ulbricht sphere.

Reviving these old findings, as I have done some Fisheye +1.4TC and +2.0TC tests today. Quint essence: if your NPP aligment is not 100% prudent you will struggle hard to get a decent thin water line. In fact you might constantly fail to get a decent over under split shot, just because of the NPP mispositioning. We previsouly concluded that if you go wider than 20mm focal length the pincussion distortion get's pretty annoying and is hard to deal with as most of us tend to tilt the camera up and down for their underwater compositions. Another thing to consider is the hyper-focal distance, to maximize sharpness of above water and below water scenes. On full frame sensors this will quickly force you to ditch diffraction concerns and set F22. On 20mm focal length you might even want more. In the Canon RF lineup there are actually not many wide angle lenses which will allow this. Most of them have F22 as a maximum. Basically you have two roads to go: add a TC 1.4x or 2.0x to the Canon EF 8-15mm Fisheye and enjoy beeing able to set your lens to 21mm focal + enjoy F32. OR stay native in the RF mount and enjoy 5.5 stops OIS + IBIS and an ultra light weight and affordable lens, the: Canon RF 15-30mm F4.5-6.3 IS STM which has also proven to be sharper behind domes than it's more heavy and pricy siblings from Canon's L line. The latter ones however will not allow you more than F22 -> so here comes the real charming fact about the grey STM wide angle zoom: it does F32 @ 30mm focal length. At the highly desired 20mm focal length it will give you F25. As I was also asked about the alignment tests with the charts above, I may have a more easy simplyfied wording for you all: If the stuff underwater looks bigger than what's on the surface, you lens is very likely to be positioned too close to the dome and you will need to buy more extension rings from your housing maker dealer. Very often these may be as many lenghty extensions as you can afford before you hit tunnel vision from the port system.

Well that does not match Phil's picture posted above. And while it makes sense, that diffent camera brands (Nikon Z, Sony E, Canon RF) have different flange to housing distances and therefore different port charts, it would not make too much sense, if Sony E Mount Camera Model X has different flange distance than model Y and Z. In that case camera X, Y and Z would need new different port charts. I think the source of 4mm gap: 43mm (measured by Phil) versus 39.1 (measured by @Isaac Szabo customer and confirmed by Marelux engineering) might have a more simple explanation. @Phil Rudin, could you be so kind and have a look if there is a blank space at the beginning of your ruler, that you have put onto the cameras flange? This is something we could not see in the two images provided.

Yes, the MFD of 30cm is too high. You will need a dome diameter of approx 52cm for it. What you can do as a solution is to put a +4 diopter on the lens to improve the focus on the virtual image. The lens entrance pupils sits approx 3.3cm too far inside the housing for optimal position of the entrance pupil behind the dome. Hydronalin in Germany has a solution for making affordable INON Glas domes work for that lens and the RF 35mm, if the +4 diopter does not do the job for you.

@Pavel Kolpakov as you are an expert on HSS as I have read here: https://wetpixel.com/articles/fundamentals-of-ttl-strobe-control-by-pavel-kolpakov/P3 Does this old statement from you, when there was mainly just the RETRA strobe supporting HSS, still hold: „For uniform illumination of the frame with such a shutter operation, the flash should be a long sequence of short flashes with a repetition rate of about 30 kilohertz, firing all the time while the open shutter slit moves along the window. The total burn time of these flashes is about five times longer than that of a mono-flash, while its intensity is noticeably lower. It is customary to regulate the power of the HSS flash by changing the frequency of these pulses.“ As you explicitly market „no HSS banding“ for your upcoming strobes. Were there strobes which showed this on some occasions? Do the current HSS capable strobes act differently? Meaning mainly: 1.) RETRA 2.) Marelux Apollo III 2.0 3.) Backscatter HF-1 Hybrid Strobe 4.) Marelux Apollo S Backscatter writes in their manual that in HSS mode the strobe power dial does not have any function and the HF-1 will fire HSS always in same strength. Contrary Marelux seems to allow adjustments in M-HSS mode. Does your 30 kHz and five times longer duration statement from 2021 still apply to the HSS strobes mentioned above and your upcoming strobe?

Well,.. HSS implementation seems to differ quite a bit depending on the strobes used. If you consult the Backscatter HF-1 manual, it says that the HSS mode always delivers same power output. This also means the picture will darken with increased shutter speeds heading towards 1/8000. Contrary to Marelux Apollo III 2.0 when in M-HSS mode you can use the strength dial and influence something.

Yes Klaus, actually that is an experience I have had for many years. There can be backscatter in video clips but actually is not as strong as the strobe. And while you mention that: In a really dirty conditioned water, when I take two shots and I manually ramp up my strobes. The backscatter discs may very often appear larger when you fire at them with more strobe power.

I think we can rule out the particle movement thing (left to right etc.) as things happen so ultra-fast, when getting strobed. Maybe electron rotation will do it's cause but not bigger molecules moving through the frame.

Congratulations. The specs read truly unbelievable and too good to be true. Especially the 120 fps above somehow contradict to the 0.8 sec recycle time two lines earlier. They would require 1/120 sec -> 0,0083 sec recycle time. 😵‍💫 😵‍💫 🤯 that's 100x times faster then the recycling speed after a full dump. I am sure all this will somehow make sense, but maybe you can elaborate a little and "demystify" this claim.

Chris there is a threshold when different matter (objects) in this universe start to reflect. https://www.researchgate.net/publication/367009373_Threshold_When_Does_a_Reflection_Become_Noticeable When there is water column between subject and light source -> this energy absorbing effect might be amplified.

Four new strobes on the horizon with unpredictable future in highly increased competition and shrinking markets.

🫣 YAFS ..suicidal tendencies among various market participants.

What do you think about this suggestion?

If you have nothing factual to contribute moderating could sometimes just mean reading, Chris. The port chart of manufacturer X does not help users of brand Y or Z. RomiK showed pretty well that EF 8-15mm is not invincible against raping it behind the wrong domes in wrong distances. Dreifish showed in this thread that the Nauticam port chart is far away from decent and prudent control pays off. Dreifish and I demonstrated multiple times with fisheyes and rectilinear lenses that every milimeter matters and very often can easily improve your IQ at almost no additional costs. If your housing brand does not offer extension rings in min. 5mm steps you should consider changing brands or buying ports and extension rings from third party port-makers.

I would not draw any conclusions from the cited article as there is not a single photo in it which wasn't cropped and heavily processed. 😁

As I already explained and illustrated in picture before, the accessory is not the issue. Even when the uw-technics TTL trigger (that's the accessory you refer to) in my housing is removed you are unable to put your trigger on top of the camera. The structural element which holds the cameras upper side in place and prevents it from misaligning with heavy lenses in the housing blocks your TRT trigger box hot shoe. The turtle trigger cannot be mounted as a non-mobie version in MX-R6II housings, please accept that. Please start offering mobie versions for all of your products.