Chris Ross

I use the neoprene bag that came with the MFO3 to protect mine during shore entries. Cinch down the cord on the cloure to keep it on. Take it off in the water and clip it off and reapply during the safety stop. Just don't let go of it as it will float away. An alternative might be a beer cooler used to keep bottled beer cold while drinking, probably widely available. You might find one around the right size. The advantage for me is it keeps the lens wet till I can soak it in fresh water after the dive. You could probably do something similar for your macro port.

It looks like the turtle manual talks to the camera as it says it automatically switches to HSS if the SS goes over max sync speed, which you would need to configure to 1/250 in the trigger, the default seems to be 1/160. You would also need to confirm the HSS will work with your Retras as it doesn't mention strobe compatability on the website. Your alternative is the Nauticam trigger which doesn't register with the camera and will sync to 1/400 without HSS. This will give you more flash power at 1/400 than a HSS trigger will deliver. It a purely manual trigger. It should be able to rear curtain sync as well as this is set in the camera and I can set it in my camera without a flash attached. I'm pretty sure it will fit, it mentions it is OM-1 compatible.

Quiet a few people here use the Canon fisheye with Metabones adapter, it's well established solution as Sony does not have a native fisheye. On the topic of 16-35, some reach is helpful however I really don't think you want to be using a big dome when chasing whales. If you look at the WACP and 28-60 and the horizontal field of view - which shows approximately how big a subject will fit in the frame, it goes from about the field of a 13-14mm lens through about the the reach of a 29mm lens, so it terms of horizontal field it is like a 14-29mm lens and compare this to a 16-35 mm lens it's more or less the same, but with better corners of the frame in the WACP and better ability to shoot wider apertures. The combination of a Canon 8-15 and a Sony/metabones on the other hand goes from a 180° diagonal fisheye with about 144° horizontal field of view through to a 28mm rectilinear lens, it's about equivalent to a 7-28mm rectilinear lens if you could get one. It's reported to have equivalent sharpness to a WACP/Sony 28-60 setup. I would suggest the 28-35mm range won't be too useful for whales, at that focal length to fit in the frame a whale would be on the deg of visibility. This post is a good one on the Sony 2x/metabones/140mm dome combination: I have an OM-1 with Canon 8-15 on metabones and that is what I would be taking if going to shoot whales.

I believe you are talking about different lenses. @dentrock is talking about the Sony 16-25, you are talking about the 16-35 II. I think the issue with the 230mm dome is living with it for travel, the size and weight when diving with it, including the drag when trying to swim with it.This is as much or more of a concern than the expense. With whales you are jumping off a boat and swimming around trying to get in position - a 230mm dome is not going to make that easy. you are also asking about flare, and mentioned problems with your ikelite port with reflections - these are different issues and causes. Acrylic ports are known to cause reflection issues and glass domes are less prone to this. Unless you are going for artistic effects flare is probably best dealt with by planning to be dropped on the sunny side of the whales and good operators will try to achieve this. If I were doing it I'd want to be using a fisheye lens, they work well in small ports and are quite sharp, you do need to pay attention to corners as they can be easy to include stray fins and other distractions on the edge of the frame. The WACP will certainly work, it's just not quite as wide.

Yes that's right, one of our members here, Wolfgang ( @Architeuthis ) uses the 8-15 with the Sony 2x and likes the setup. The downside is it's not as sharp as the bare lens, but if I recall it is about as sharp as a WACP-C, there's a thread on here about using this setup. You mount Sony 2x on body, then Metabones then the 8-15. Very flexible. I use an OM-1 in combination with a Canon 8-15, with the crop factor there is no teleconverter and I get the same zoom range.

So you are saying pressing the AF point button outside the housing activates display off, but inside the housing it won't work, but other functions assigned to that button work inside the housing? Maybe there is a eye detection function in the camera viewfinder and inside the housing it thinks there is an eye at the viewfinder and won't activate the function, because it thinks you are still using the viewfinder? You could test by covering the eye sensor to see if it stops activation outside the housing?

Fair enough, though I would add that ports for Isotta seem to be a quite a bit cheaper and particularly extension rings when you look at the prices for the type II rings from Nauticam - that's a long term cost if you add more lenses later. The Canon 8-15 with metabones and Sony 2x is also a fine option, about as good a quality as WACP-C according to posts on here and combines a 180° diagonal fisheye, the field of a 14-28 rectilinear and the wider end of the WACP. You can use it behind a Nauticam 140mm dome among other options such as Nauticam 4.33"acrylic dome and even the tiny Zen 100mm dome (at the cost of some corner performance). In Isotta you don't need the N100-N120 adapter and you could use it with the 4.5"glass dome.

The adapter is basically an extension tube with different bayonets on each end, so has no impact apart from adding some extension. As long as you can get the right extension length It's no different to using a native Isotta port. The difference you do need to consider is that the Nikon DSLR Tokina 10-17 doesn't work on the Z50 as it has screw drive AF. The solution is to either adapt a Canon version 10-17 or to use the Nikon 8-15 on a FTZ adapter.

I would suggest you try polishing with cerium oxide others have reported it works, you would just need to sure the materials used when polishing have no grit in them- you need to get optical grade material, this link talks about it: Polishing vs Regular Grade Cerium Oxide: How To Choose?Discover the essential guide to choosing the right grade of cerium oxide for your polishing needs. Learn the differences between Polishing and Regular Grade cerium oxide, including insights on purity,

My concern would be the rushed decision. You are coming from Ikelite so nothing will carry over. Do you want to go with Nauticam? Isotta will be somewhat cheaper but you would have to wait for the A7RVI to appear, in particular their ports and extension rings are quite a bit cheaper. To use a WACP-C based on prices from UW camera store the housing zoom ring and adapter come to 3873 euro with Isotta and 4550 euro in Nauticam. You would need to add the WACP port, lens, camera etc to that total The Isotta housing will be more compact and uses B120 ports while the Nauticam is N100 and requires the pricey N100-N120 adapter for many lens combinations. Isotta have published a port chart for using Nauticam wet lenses on their housings here: https://www.backscatter.com/images/article/content/Port-Charts/Isotta-port-chart-Nauticam-Lenses.pdf Your other option in this regard might be a WWL with the 28-60, somewhat cheaper to purchase and reported to have very similar optical quality. You could do this in Isotta as well.

No port system, it's a fixed port and it allows you use the 16-50 kit lens or apparently the 50mm macro fits, but it has pretty short working distance. If it were me, I wouldný want to use the CMC to get just 0.9x with little to no working distance. You can take decent pics, but it's a kludge solution compared to a real macro lens.

I haven't used them but I find the idea of the Nauticam systems using only a kit lens with either a diopter or WWL somewhat limiting. In general the the WWL is sharp and provides good to great images by all reports, however the width of the frame is about that of a 14mm rectilinear lens, the barrel distortion gives a 130° diagonal, which seems like a 10mm lens, but with barrel distortion the corners are stretched the consequence being is the horizon frame field is about that of 13-14mm rectilinear. Macro is another story, you can add diopters and get near macro magnification but working distance is very limited. the 16-50 with CMC-1 gives you 0.9x at 45mm working distance. Compare that to the 105mm Z lens which gives 1:1 with about 120-130mm working distance. The 16-50/CMC-1 only focuses between 45 and 75mm from the front of the diopter so only gives quite a limited magnification range. I'd estimate 0.9x - 0.4x approximately. It seems there is an adapter available for Sealux to Isotta (looks like a custom order so a bit of a wait), I'd be strongly tempted to go that way if macro is important to you. https://www.uwcamerastore.com/isotta-adaptor-ring-for-sealux-1p

The compact port extension is #18520, to check this just search for Nauticam 18520. The compact port system is an old system and as far as I can tell has to be used with the compact port base. You are talking about using N100 and N120 systems. Looking more closely Nauticam don't make a N100 20mm extension, so your only option is an N120 20mm extension. I understand about not wanting to spend big up front, but the 20mm extension may become an expensive paperweight, depending upon which lens you eventually switch to. At Backscatter the N120 20mm extension is $660 longer extensions are $700 plus. I'd suggest understanding better which lens you hope to use and match it to your photography goals - buy right - buy once. The obvious solution it seems might be a 16-35 lens, but other solutions are significantly more popular UW wide angle photography - fisheyes and wet optics specifically. The right choice for you will really depend upon what you want to shoot. To get you started on 14mm lenses see this thread: There are other threads on various Sony wide angle lens options if you use the search function.

The only reason I think that might give you trouble is if the lens is too wide through the N100 part of the extension. Obviously the bottom part will but this is a fairly fat lens that only gets narrower right at the bottom, but I expect it's probably OK. You can test to see if the lens fits through the N100-N120 you already have. The question you haven't asked is if you really want to use this lens UW? Wide rectilinears have their uses of course, but the 180mm dome geometry requires the lens to be positioned with the entrance pupil forward of the optimum point at the dome centre of curvature to avoid vignetting, meaning the lens won't perform as well as it would properly positioned. You will see that the port chart shows the 250mm dome with an " * " meaning that is the optimum dome to use. The 180mm dome will certainly work and the images produced will be usable but other lenses may well do better particularly in the corners, There are other Sony lenses which may work better with the 180mm dome. I would suggest asking for experience using the Sony 180mm dome with the 14mm f1.8G lens, to see if you would want to do that. Apparently some of the new 16-35 lenses work quite well with the 180mm and I think there have been some tests published on this site from memory. The other question is what sort of photos are you thinking you might like to take and is a 14mm rectilinear the best option for this?

Be interesting to test it out, the test case would probably be shooting into the light, like a sunball or something.