Chris Ross

I don't know enough about optics to give a 100% accurate explanation on the ability of some lenses to work well in small domes. However the basic premise seems quite straight forward which is the ability of the lens to render the curved virtual image and have it all sharp and in focus across a flat sensor plane. We have seen that some close focusing lenses do a particularly good job at this. Certainly a lens being able to focus close it seems helps in this situation, but as I understand things most WA lenses don't have a perfectly flat focal plane and rely somewhat upon depth of field to render images sharp across the sensor plane. I notice that the newer Sony lenses are particularly good in smaller domes, while it seems the RF 15-35 isn't as good even though it focuses close. The amount of curvature of the focal plane may interact with the curved virtual images in ways that are more or less beneficial. A lens may have a flat field at infinity and develop field curvature as it focuses closer and the direction of curvature can reverse as well. The shape of the focal surface can be found on Photons to Photos optical bench. For zooms it is only available at infinity, some primes allow you to adjust focus and observe how it impacts the shape of the focal plane. If you look at optical diagrams for the lens elements you can see that the zooms within a given manufacturer have similar layouts. If you compare the Sony 16-35 f2.8 GMII to the Canon equivalent the lens element layout if quite different and seems to be different to earlier Sony 16-35 zooms. On the issue of microcontrast, you could of course test that by taking shots with the 140mm dome a little closer. Not sure why it would be less in the 140mm dome.

It depends - is the 55mm adapter one that was sold as allowing use of adapted Canon EF lenses with Fuji? If I recall correctly the last line of the port chart used to include an adapter designed for this purpose and the Nauticam gear would mate up to the Zoom knob on the adapter. If not you would need to work out the correct extension to use.

In theory it should work just as well as the Tokina 10-17 on any other APS-C body, so same zoom range and image quality. The only variable that is unique to the Fuji- Tokina 10-17 combination is how well the adapter plays with with the Fuji cameras. You could search around to see how the AF works with various adapters on land based applications. Metabones publishes known limitations for their adapters. https://www.metabones.com/products/details/MB_EF-X-BT1

The specs say it's 7.2V so it must be either 2 or 4 cells.

The magnification obtained with the 5T is not as high as typical wet diopters like the Nauticam SMC-1 which achieve something around 2x magnification. It will get you something like 1.3x on a 105mm macro lens. Also it means you can't shoot larger things that you find as the lens no longer focuses to infinity, being able to take the diopter off UW is the bige benefit of thaw wet lenses.

Can't help with the extension required. However I suspect the screws are really not needed when you have a vacuum. If you have the reported 200 mBar vacuum on the housing the the closing force is around 22kg. The extension ring if push and turn and it's not going to come apart with that type of closing force. I see the Type II ring is now offered, it's still push and turn but has an internal lock.

I would say it depends on what you want to do with it for 90% of your shots with it to some extent. If you're mainly doing splits you'll benefit from the bigger domes, but if it's occasional splits, you want to travel with it and do CFWA then you might want a different compromise. The 230mm dome is a big beast and difficult to travel with, the 8.5" a bit more manageable. Neither are ideal for CFWA due to their size. If the 230mm/8.5"dome is too big for you maybe adapting a different dome might be a good option, something in the 7-8"range Nauticam recommend the 140mm dome as most optimum as it's the only one in their line up that allows you position the Entrance pupil correctly at the dome centre of curvature. It's fairly good for CFWA and great for reef scenics, but a little small for doing splits easily. The other domes can't do this as they are not full hemispheres. Doesn't mean they won't work, just not optimum, the corners maybe not as good and the angle of view changes a little, however many people would be happy with them. You don't want the 180mm as it's quite a small sphere segment and you need to have the lens well forward of the optimum position. Finally if you want to use the 8mm end of the lens you need a removable dome shade.

That's not how it works, the W-hr for each battery is additive. The amp-hr capacity remains the same, but it is the same amps at a higher voltage which is more energy. For AA Eneloop total capacity is 1.2 x 2.55 x 8 = 24.8 W-hr for AA lithium it is 1.5 x 2.2 x 8 = 26.4 W-hr The new battery pack is possibly using 4 x 18650 cells of 2770 mAhr capacity in 2 parallel two series arrangement. Comparing to other battery packs it looks better value for sure, but 4 x 18650 would be at most $US80 retail price so it's quite a bit more than 4 loose cells, which is why people are complaining. I agree with Dave Hicks though, if others can make a strobe using 2 x 21700 cells it would seem to be a good solution as long as people buy good quality protected cells.

So if you are after a 200mm dome port you could look at this S&S dome: https://www.backscatter.com/Sea-Sea-DX-200-AR-Underwater-Dome-Port Can be used on Nauticam N120 by changing out the rear lug ring. Confirm with the dealer before buying that you can still source the lug rings (and that S&S still have them as a bolt on piece). Likewise you should be able to adapt Isotta ports. Finding the lug ring for sale might be a an issue though Backscatter mark them discontinued. I see now though they have a 20mm Nauticam to S&S extension ring: https://fotografit.eu/products/36-nauticam---dslr-ext-rings/420-sea-amp-sea-to-nauticam-extension-ring-20/

I didn't realise that's how Sony hotshoes were connected until recently. When I first saw it I thought it was a problem waiting to happen. Pavel has said he thinks it's not a strong design and a google search found a few complaints about it as well. One approach might be to order a spare hotshoe for triggers with separate hotshoes. On land you can potentially deal with any problem by jiggling and re-seating plus land flashes have a clamping mechanism that jams the contacts into the hotshoe. Maybe Sony triggers need a similar arrangement?

I came across this post showing the underside of the trigger: I would be looking carefully at those two pins you can see on the underside checking they are clean and making good contact. Maybe try some contact cleaner?

Sounds like you have done all of the tests I can think of. I would suggest messaging Balage, the owner of Turtle, he's on the forums: https://waterpixels.net/profile/267-turtle-balage/?wr=eyJhcHAiOiJmb3J1bXMiLCJtb2R1bGUiOiJmb3J1bXMtY29tbWVudCIsImlkXzEiOjUxOSwiaWRfMiI6MTI3M30=

Are both strobes doing it? this tends to indicate a cause outside of the strobes. It would be odd for both to develop the same fault at the same time.

Can't help you with the intermittent issues related to your shutter button, though I suspect some of the problems associated with Sony hot shoes is the interface design they have with those tiny little contacts. Compared to the traditional flash hotshoes getting poor contact through those pins is not the least bit surprising. The fact that it can wriggle back and forth in the hotshoe would be my first target, I had a mini flash unit fail to work from that cause due to lost contact. I would suggest experimenting with the hotshoe cable a bit. You might be able to pad it out or even jam a toothpick in next to the hotshoe plate to prevent the insert from moving. You say it is a Nauticam trigger - that is manual Only I would guess? Does it have the small pins across the front or does it just use the centre contact?

Welcome aboard Zane, good to see another Aussie joining up - you're Australia based now?

You need to look at the top view as well to see how controls line up there, the critical ones being on/off switch and the control dials. I found the camera decision page and they had top view comparisons, I cut out the R5 and overlaid it on top of the R6 II at 50% opacity: Perfect alignment is not possible so I lined up the lens mounts which is how they would go into the housing, It looks pretty close on first view but the R5 has the on-off switch where the R6 II has a movie/stills switch and they don't line up, while the R6 has a mode dial where the R5 has a top LCD. the rear control dial is also a little out of alignment. For the camera controls to work reliably the dials/buttons need to be aligned to sub millimetre precision and this is only rarely the case between different models. This seems like enough to render the R5 very difficult to use in the housing even if you could live without rear mode dials and on/off switch. null

The other solution for the 14-30 and 15-30 might be zooming in a little bit? Can you zoom in enough to use the 50mm extension without vignetting?

If the magnet won't activate the switch then it likely needs replacing. I assume you've tried swapping with a known working magnet and swapped the magnet out from the bad strobe to another one to prove it's not the magnet. If this is the case there's nothing else you could do externally and you'll need to find a repair agent. It should be a relatively simple repair too replace the switch for a service agent.

It does hold the vacuum, I know it's pricey, but it's cheaper than the Dive and See bulkhead I was looking at which is $US390. the short USB cable is also a good idea.

I agree these solutions are what I call kludges, they work but have a range of caveats. For example going for a macro wide solution for APS-C forces you into a 60mm macro lens which is not ideal. If you are on Sony APS-C the short macro don't work so well. The Nauticam solution on the MWL sounds good but you are at f14-16. Even the FCP produces good image but has very restricted depth of filed in CFWA situations. The most straight forward solution is the WWL/WACP and it works seamlessly on Nauticam but doesn't give you a full frame fisheye option. A zoom fisheye in a dome really doesn't have any of these issues, the only problem is having to adapt a zoom gear on Nauticam. If a camera manufacturer introduced a 10-20 APS-C of 15-30mm full frame zoom fisheye lens it would be the ideal solution. For the moment you only get this with cameras that can use a Tokina 10-17 or with m43 where you can adapt the Canon 8-15.

Not that I'm aware of, it's an extremely simple part though. You can use the the Nauticam gear directly on the tokina 10-17 mounted with a Metabones speed booster as for some reason the 34.7mm N85-N120 was designed to mount EF lens in combination with the speed booster which is thinner than 1.0x glassless smart adapter. The Tokina is a good solution but it doesn't have the zoom range and becomes a 7-12 mm lens with the 0.7x speed booster. IMO it's worth finding somewhere that can print you one for the extra zoom range of the 8-15 lens.

Yes It's the Nauticam system and the standard arrangement is as follows: 140mm N120 dome 35mm N120 extension N85-N120 34.7mm adapter Nauticam zoom gear 3D printed adapter for zoom gear to position correctly the zoom knob on the adapter Then an 8-15 lens and a metabones smart adapter (not the speed booster) The zoom knob on the adapter is a bit coggy doesn't feel the same as the zoom gear on the body. I'm going to try getting a zoom gear printed for the housing zoom control, there's not a lot of room for it but would be better zoom I think it it will work. I ran out of time before a recent rip to give it a try. The USB-C bulkhead is nice - but only works for OM-1 for battery charging, it can be used to download from other cameras. It's a Nauticam one, be sure to get the specific M28-M16 adapter as it won't fit through the original part number adapter. I'm going to do a mini-write up on it. Here's a sample from Kimbe Bay in PNG (New Britain)

I'm not sure how a quote of my response to your post about WACP and other wetlenses managed to make it's way over here to your intro post - but the post quoted above is all about the field of view obtained with a WACP vs an 8-15 with 1.4x.

The Tokina 10-17 was in fact indirectly on the old Sony N85 port chart, the final entry was an N85-N120 adapter with zoom knob that matched to the Nauticam zoom gears so that you could use any EF lens on a Metabones adapter. With that system the Nauticam zoom gears for the Canon lens would mate up to the Zoom knob and be controlled from there. The latest port chart omits this option Similarly on that question around EF macro lenses yes you could but you may not want to. The Metabones generally provides acceptable performance on wide angles but macro lenses at high magnfications are less likely to work well. I ended up upgrading to an OM-1 for other reasons and now have an adapted Canon 8-15 working on that system and it gives me full frame fisheye through to about the field of a 28mm full frame lens so combining a Full frame fisheye, a 7-14mm lens and the wider end of a WWL into one package. SO I have an FCP equivalent package (zoom range- wise) for a small fraction of the price of an FCP and without the CFWA narrow DOF restriction. Zooming in the get your framing is a better option than cropping IMO. I shot this system in PNG recently and I bought the USB-C bulkhead which meant I left the camera/lens in the housing the whole trip and download images and charged the battery through the USB-C connector.

To understand things better I feel it is better to look at the horizontal field provided by the various lens options, the reason being that with barrel distortion the corners get stretched proportionally more. For example looking at the diagonal field of the WACP/WWL or 130 deg you might think it matches a 10mm rectilinear lens. However if you look at the horizontal field which tends to define what you can frame with that lens it is quite close to what you would get with a 14mm rectilinear lens. From what I can tell the barrel distortion of the WACP is somewhat similar to what you would see with a fisheye zoomed into the same field. The distortion lessens as you zoom in more. That is not say it is interchangeable with a 14mm lens for a number of reasons including close focusing of the WACP and lack of the fisheye impact bringing subjects forward in the rectilinear. The coverage provided by the WWL is something like that from a 13/14mm - 33mm rectilinear lens, just a bit wider than a 16-35mm. The horizontal coverage is around 111-58 degrees. The 8-15 fisheye with a 1.4x covers full frame fisheye with 144 deg wide frame zooming into about 100 degrees or in rectilinear terms the same horizontal field coverage as fisheye to about a 16mm lens. As to which to choose, it's going to be the one that matches your preferred subjects, if you need reach for subjects that don't approach too closely it's likely to be the WACP. If you like the fisheye impact on reef scenics and CFWA ten perhaps the 8-15 with 1.4x.