Adventurer

Interesting! Could you clarify which of the two has more DOF ? Or better rank all three optical options, with best DOF from 1. 2. 3. top down?

Canon Rumors still insists: Canon RumorsCanon EOS R7 Mark II Coming Soon? - Canon RumorsCanon is preparing to announce the EOS R7 Mark II and new lenses in the coming months. We expect more stellar products in 2026.

You should bring up the Insta360 AcePro2 on your radar. It‘s slightly more capable than the GoPro and the Osmo with the out of the box footage. Personally I use Insta360 AcePro (version1) as a small secondary cam and that one already smokes the other cams around. Due to the larger sensor and leica optics of the insta you already notice slight performance differences in the underwater optics. I have tested AOI, Backscatter and INON underwater action cam optics and found the INON image quality to be slightly superior than the others. There was also a thread here somewhere on the forums seconding my personal impressions about the superiority of the INON action camera optics.

Have you tried frame rates below 10 fps and above single shot mode ? That way you can rule out the general issue coming from camera or trigger. As you can see in the Henley Spiers strobe comparison photos: at 7 fps already the 2nd frame gets pretty dark and the RETRA is struggling at more open apertures.

I just recalled that Henley Spiers has shown the RETRA fast recycle time performance in his review: https://www.divephotoguide.com/underwater-photography-special-features/article/first-impressions-marelux-apollo-iii-2-0-strobe It‘s showing a lot of struggle at 7fps. The Marelux strobe smokes the oneUW and RETRA in this discipline.

10fps are done at easy with Marelux strobes at full power in their ultra-fast MTL mode. But you have to use them in MTL and with fibre optic cable (not Lumilink) to squeeze out the maximum repetitive performance. They are currently leading the fast recycle time without blackout frame technology in underwater strobes. Here on the forum is a pretty dismal measurement of mx strobe strength by dreifish though - something I could not agree to when comparing it 1to1 to my Backscatter HF-1. I can only assume the Apollo tested by Dreifish must have been a monday model or malfunctioning pre-production unit. On any AA eneloop powered strobe you will struggle to get fast recycle times near 8 - 12fps. You need a strobe which utilizes 18650 or 21700 high current discharge cells. Otherwise the capacitors cannot fill back up at the speed you desire.

Not an Ivanoff Optic but a Rebikoff Underwater correction port will also create a somewhat „virtual image“ similar to a dome. Contrary to dome port the corrective effect can already be seen in air, but the image is not improved in air.

Chris we have to stay sorted here, so everybody is on the same page and not mixing things up. There is no such thing as a sole Ivanoff optic working standalone and making your underwater image better. There is just Rebikoff-Ivanoff Optics, where the Ivanoff Element does Step two of the optical correction. Contrary to sole Ivanoff Optics, the Rebikoff corrector port can have a positive effect with increased IQ when used alone, simila but still different to a dome port. The Rebikoff corrector port will look very similar to a flat port when viewed from the outside, mounted on a housing. So for everybody going first time into this, there is: Flat Ports Domeports Rebikoff uw correction Ports Rebikoff-Ivanoff uw correction Ports

I would like to give everybody an update about my time and shooting experience with the above optic. Overall resumé : I am in deep love! The setup I am shooting with the Canon RF24-105 STM is a dream combination, filling the flexibility gap between my 8-15 Fisheye and the 100mm macro lens. Beeing able to shoot substantially wide dent Sharp reef scenes and fish portraits on a single dive with a full frame mirrorless system is amazing. However I would like to put some terms straight that may have been coined wrongly by the Keyword „Ivanoff Optik“ inspired by our dear Dr. Alex Mustard and who got me started researching and exploring this road. Alex was in fact shooting a Ivanoff-Rebikoff optic with 20mm fixed focal lengths, which is internet keyword wise sometimes just referred to as Ivanoff-corrector Port oder Ivanoff-Optic, leaving out the credits for Mr. Dimitri Rebikoff. During diving deeper into the topic, I found that I am actually shooting a Rebikoff optic, which goes without the correcting inner collection lens presented in their later introduced Ivanoff-Rebikoff design (sometimes referenced as IR design). All three approaches have their caviats. And as you have just read 3 instead of two, yes Rebikoff fronts glas uw correctors Ivanoff-Rebikoff corrector ports Dome ports ..share some commonalities in what’s possible concerning their optical limits. Most importantly the entrance pupil position problem cannot be thrown overboard with any of the above design. Furthermore they also benefit all from the same factors defined by the hosted dry air lens inside of them. The Ivanoff-Rebikoff design and Domeport have in common that they will extremely benefit from lenses that do not very much move the entrance pupil, most commonly found with fixed focal length. This explains also why Alex‘s IR-corrector port works splendid with a certain 20mm lens and created dismal results when trying to apply „the cure“ to other lenses. While everyone of you can easily work on optimal dome port position, you will very much likely fail in computing and manufacturing the exact Ivanoff Element for an Rebikoff-Ivanoff underwater corrector port and your lens; for the sake of beeing extremely costly. My suggestion for everyone is, if you are into exploring paths offside your dome port try to find large 2nd hand Rebikoff underwater corrector ports and start approximations with lenses from your camera brand, Nikon Z, Canon RF or Sony E-Mount. The latest UD elements and other 21st century master technology may help you to luck into a system that outperforms other optical underwater solutions you dived. For some extended reading about Rebikoff and Ivanoff .. their work and later collaboration I recommend these articles: https://blueexplorermag.com/2023/10/28/illuminate-the-abyss-the-innovative-inventions-of-dimitri-rebikoff-coloured-the-underwater-world/ https://spie.org/news/photonics-focus/julyaugust-2023/dimitri-rebikoff-pioneer-of-underwater-photography https://frogmanmuseum.free.fr/html/camerasandvideosrebikoffen.htm https://www.collection-appareils.fr/x/html/camera-5074-Alpa_U-Phot.html

I totally agree to your impression and did not understand why Seacam picked this particular difficult focal length to run their tests and first Ivanoff-Element (the part that screws onto the lens). It‘s worthwhile mentioning that a Rebikoff-Ivanoff optic will not be designed for zoom flexibility and you run into similar entrance pupil positioning issues as with wide angle zoom optics behind a dome port. The Ivanoff-Element is the part that will make your system afocal again and tries to get rid of chromatic abberations etc. The optical designers of the Ivanoff Element will have to make compromises in optimally correcting it for different zoom positions. When the lens is off these positions the underwater photographer will have to sacrifice IQ. As with Domeports and Watercontact Optics finding the right „Symbiosis lens designs“ from the topside lense choice will keep playing the critical role.

Nope. It‘s complete as it is and delivering dent sharp underwater images. All required optical elements are included in the main module. There is Ivanoff style and Ivanoff Rebikov designs, plus multiple variations derived from this principle.

Tales from the YAFS* corner… (YAFS = Yet Another Fu…. erhm Fabulous Strobe) BACKSCATTER announced the Atom Flash: Backscatter.comBackscatter Atom Flash Underwater Strobe AF-1Backscatter Atom Flash Underwater Strobe AF-1: With an underwater guide number of ƒ28, the Atom Flash packs serious flash power for its size, lighting everything from the biggest wide-angle scenes to

Are you sure ? It's heavily marketed everywhere! I still hope that the combination of Electronic Shutter + FullFrame Res will allow you to have X-Sync of 1/320s That would explain the above exeptions.

If people are on a limited budget or have limited luggage the INON S-220 is the goto strobe ! If you can crank up the ISO of your camera a little you can compensate, not bringing a large gun such as the HF-1 or Apollo III 2.0.

The new x-sync speed is a real treat and makes me consider it as another camera body next to R6II. The additional megapixel count raises the attractiveness even more.

I did quite a while ago in this forum. It is very funny how similar it looks to the new Seacam solution. However it‘s noteworthy that I can use mine without a 2nd component on the lens: Thread name: Ivanoff Style underwater corrector port on a Canon Marelux MX-R6II

What an irony 🫢🤣 I am diving my Ivanoff Optic now for 6 month at a fraction of the costs and with more corner sharpness I observe in the sample images on the Seacam page and in the teaser. But I am sure Seacam users will buy this anyway. Glad to see some general progress and competition in the underwater optics field again.

Found it 🤦‍♂️ https://waterpixels.net/forums/topic/2417-list-of-underwater-monitors/?&do=getNewComment

Thanks Davide, for the amazing compilation! Do you mind adding a column to show the monitors resolution. The nits values are nice but an important information might also, if they do 720HD, 1080HD or even 4K.

Somebody tried to make a recent underwater monitor market comparision table, but I do seem to find it anymore in the forums? 🤔

I have the impression, this is just a slight perspective shift resulting from two different photos taken. Putting myself in Canon's product management shoes, I would try to utilise the same body tooling + parts when the design change and upgrades are all internal. So I conclude the camera body is very likely to fit in all existing R6 II underwater housings in the market. Let's wait and see for the confirmation.

The today freshly announced Canon R6 Mark III might fit in R6 II underwater housings and natevily offers now X-Sync speed of 1/320 putting it close to this charming Sony A1 feature 🤩 https://m.dpreview.com/reviews/canon-eos-r6-iii-initial-review Flash sync speed 1/320 sec

I think the above image by @Dave_Hicks already answers your question.

Though I am very happy with the HF-1 in that particular point I do agree with you, Dave. To what manual power setting do you reduce the HF-1 to archive 30fps? When I set my Backscatter HF1 to 1/4 power setting it will hardly do 8 - 10 fps with many blackout frames or dark frame variance. In that discipline 1st price goes to Apollo III 2.0 which is slightly stronger in full MTL mode and will have zero blackout frames and no variance in light output.

The HF-1 is the most powerful of the named strobes. Also it will shrink your battery handling substantially down. I refer to just two batteries per strobe and having to change/recharge these every 2 - 1.5 diving days. As you may guess from the above, I am a happy HF-1 user and owner. If recycle time is an issue consider the Marelux Apollo III, the latest version is about as bright as HF-1 in Full mode (not +1 or +2) and will deliver more fps without variance or blackout frames. As a Sony owner you might clearly lean into HF-1.