Chris Ross

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.

Nice, I'm yet to dive from up there, it's on the list though

There is good reason they are locked, so that people don't change their post in the event of a dispute. I do agree a mark as sold button would be worthwhile, but not sure if forum software allows this. We can check.

You can download the manual which will include how to setup the strobes - just go to the S&S website. They have a few procedures to customise the strobe to work with various cameras.

It's been a long time coming interesting to see if it was worth the wait, so far I can only find pre-order with some basic pics on the two sites mentioned.

expect you're right, I couldn't see the connector which is why I mentioned it.

You should also probably remove the trigger as well - is it an UWT trigger or some other type? What are the cables attached to?

They could be different types of glass, there are many different types of optical glass around. BK7 is one of the most common. The procedure is straight forward - on a dive boat either keep the lens wet or apply the wet neoprene lens cover and keep it cool. Soak the lens for a period in fresh water. Then remove it and dry it straight away. I have a battery duster that I use, you could also use a blower attachment on a scuba tank or a compressed ir hose, depending on what you have available. Then dry with a microfibre cloth.

Perhaps, but in general higher concentrations of salts are more corrosive, in any case you can't dissolve these markings, maybe they have etched the glass, maybe the compounds have chemically combined with components in the glass. Apparently BK7 glass (a common optical glass) only has moderate chemical resistance. This topic has been raised many times and reports are dissolving the spots doesn't work and they require polish to remove. Whatever the mechanism, the cause is still allowing water to evaporate on the glass and the prevention is blowing off or wiping dry so evaporation doesn't occur. Apparently cerium oxide is slightly softer than BK7 glass and can polish without causing micro scratches.

could be different glass compositions? in any case the cause doesn't change and allowing your rinse water to dry can do this. What is your fresh water like? Is it hard water? This makes things worse as hard water is caused by alkaline salts and they can etch (corrode) the glass if sufficiently concentrated. You can use a blower or a nozzle attached to a tank to blow water off.

Unfortunately this is a case of prevention being better than cure. This happens when salty water is allowed to dry on the surface. The salts concentrate and the pH increases and eventually it etches the glass. Some people have reported success using optical grade cerium oxide to polish. This risks damage to anti reflective coatings, so use at your own risk, but there are reports of it cleaning the surface up reasonable well. To prevent keep the glass wet till you can soak it in freshwater. When you remove it it blow it dry and wipe with a microfibre cloth to prevent the droplets evaporating on the surface. Even the rinse water drying repeatedly will eventually etch the glass surface.

Welcome onboard Don, good to see you here.

The answer is in the port charts, Nauticam publishes this data for all their wet lenses. The CMC-1 and L10 covers a field 33 x 25mm approx with the CMC-1 and working distance is 51-72mm. So a Shaun the sheep at maybe 3-4mm long will fill around 10% of the frame. With the working distance of 50mm, getting more magnification with other wet lenses will be a challenge as it will eat into working distance. Diopters work by allowing you to focus closer. You can review the port chart to see what cameras allow more magnification - some of the Canon compacts will get you about 23x13 at similar working distance and the Sony RX100VII will get 16x10 at 90mm and even closer with more powerful diopters but lacks working room. The downside of the RX100 is the need to swap ports to get the best out of the lens with wet wide optics. The parameter here is the focal length of the lens, the longer the focal length the more working room and the higher the magnification with a given diopter. If you really want some magnification you can't beat a interchangable lens camera, the olympus 60mm macro will cover 17x13mm without a diopter 10 x 7.6 with a CMC-2 with 30-93mm working room. Port chart is here: https://drive.google.com/file/d/1m9xE92aU7oWuZ5SohUoXAudpZSK_7EaX/view

When I shot the Panasonic 8mm with Zen dome and also with the 60mm macro currently I used a pair of INON mega floats with 390 gr each buoyancy which was about perfect for both setups, being about 100-200 gr negative. I do see they now have a new model which has 460 gr which might be a little too much, though the Olympus fisheye is about 150 gr heavier which is about equal to the additional weight. I actually switched to using the mega arm with a 135 gr float arm I have since adding the 45° viewfinder, so I'm fairly certain the 460 gr float alone would work. I pair it with a standard 8"arm plus a long clamp between the two. The arm is the Mega arm model S: INON_globalINON Arm System [Arm]Official web site of INON INC. Manufacture of underwater imaging gears, strobes, conversion lenses, arms, housings and more.

Believe it only does S-AF, can't do C-AF, so not so good for video, unless you are shooting with certain Sigma lenses apparently.

Right I'd forgotten that so back to a converted 8-15 if you want a TC option.

No I'm talking about the Canon 8-15 with Metabones in reply to the original question about a Canon 8-15 with Metabones, with 2x nose fitting into the Metabones which requires the latest version if I recall correctly as earleir versions were smaller ID. I 'll edit the text to make this clearer.

The biggest issue is actually that if they make this lens in SONY mount, it will mount directly to a Sony body, no need for a converter incorporating the additional back focus needed for the DSLR lens. This is what allows the Canon 8-15 to work the Sony TC with the nose of the TC inside the converter. I think also the exceptional optical quality of the Canon 8-15 helps it work as well as it does with the 2x. TC magnify the image and the aberrations so the lenses that work well with them are exceptionally good optics.. Certainly be nice to have a native Sony fisheye, but it would be restricted to the Kenko TC, which as I recall doesn't have as good optical quality in the 2x version compared to the Sony TC.

The PCB board I linked earlier would fit with next to two 18650 batteries I believe. I say 18650 as this would leave space for a battery holder so you can pull them out and place them in a separate charger. two by 3600 mAhr 18650s would give you just about 26 Whr in capacity. Of course an off the shelf model would be simpler to hook up if you can get something close in capacity.the right size. This could be close: Cygnett powerbank It has PD so doesn't need a separate PCB it seems, does 9V 2.2A so not quite up to spec for solo running but should have plenty of capacity for you.

Not much getting around it, occasionally you'll find an adapter second hand, I found one at about half price. You could wait and see on the Laowa newly announced but there maybe issues. If you have any interest in using it (edit: it = Canon 8-15) with the Sony 2x for an extremely flexible 180°diagonal fisheye that zooms to a 28mm lens equivalent in horizontal coverage then you need the I think the latest version metabones as the Sony 2x nose will fit inside it. Requires a custom zoom gear printed which easy enough as designs are developed and available.