Chris Ross

Sorry, you actually do need liquid water to setup an electrochemical reaction, a thin film of salt is enough to do it as salt is hygroscopic and will pull water out of the air. But unless the humidity reaches 100% you won't get any condensation and even pure water needs a little in the way of salts to become conductive enough to facilitate dis-similar metal corrosion. I'm quite familiar with corrosion mechanisms in my line of work. It won't happen if the contacts are dry. Leaking batteries of course can cause it as they leak electrolyte. Regarding copper, it is quite resistant to sea water corrosion, but tarnishes quite readily which can reduce conduction. Regarding Coca cola, it contains phosphoric acid which will clean away corrosion products. you just have to rinse it well or the residue will be hygroscopic and come back to haunt you at a later date. I just looked at my Z240 again, bottom contacts seem to be brass, maybe gold plated?? but totally tarnish free after 10 years, the spring contacts in the insert cap appear to be stainless steel. Stainless is much less prone to tarnish, it's electrical conductivity is not as good as copper/brass but I expect it's good enough.and you can compensate with thicker cross sections. I never opened them up under suspect conditions like on a boat with strong winds blowing, but always made sure no water was left clinging to the o-ring before re-assembly. I think the issue is the high currents required, they make a big deal about having properly rated batteries - unless the contacts are good the extra resistance will just reduce the current. I don't think they cause the corrosion as such but are more sensitive to the impact of it.

Hi Tim, welcome aboard, good to have you here. I dived Byron a couple of years back, must get back up there.

Must be made with poor quality material, I'd expect this for materials left outside for extended periods, but not metal that spends its whole life inside a battery compartment sealed off from the outside. My INON Z240 strobes i had for 10 years and the contacts in the little cap thing and inside look as new. Dissimilar metal corrosion requires some moisture to condense, now if you get a trace of saltwater inside that will draw in moisture and can start corrosion. I always pulled my o-rings every time I opened them as I could see water droplets clinging to them and dried them off and wiped out the water in the o-ring groove before replacing them, if any of that water gets inside it will cause problems. My new Retra strobes don't seem to gather droplets of water so readily so those o-rings stay on most of the time and they are serviced periodically. The best is my INON torch which has a sand seal which basically means water never gets on my o-rings.

The port charts list the two 30mm macros and the 12-50 so it seems it would work with the 45mm. I'd estimate the field would be be a bit wider than the 12-50 - about 24mm FF equivalent in terms of horizontal field. The MWL seems like a great idea but never really took off and there is probably a reason for that. For one thing it is said it needs to stop down to f16 to be at its best which is well into diffraction softness with m43. It seems not too dis-similar to my situation in Sydney, I mostly dive Macro and regularly see things that would benefit from the MFO3, but possibly might see a big subject - a grey nurse shark shows up occasionally as do other things like wobbegongs, large rays etc. I still dive with the macro setup and now the MFO3 as it covers 95% of what I shoot very well. There is FOMO of course but I'd rather have a system that does well on the most common subjects. I'll occasionally dive with something wider at this site.

No I don't have a tether, just need to pay attention when mounting the lens. It's worked OK so far. I used cargo shorts in lembeh, but reverted to a dock on the float arm diving in Sydney. The weight of the lens causes the shorts to fall down over time when walking any distance - not an issue when you are just falling off a boat but a real problem shore diving.

It seems to me that a 30 macro will do several things but mostly none of them well. It's really not wide enough for a really big subject and you need to back off too far, while it is fiddly to use on average size nudis and the like as you are in too close, I don't know what your dive sites are like but I find the housing contacts the rock the nudi is sitting on if I have to get too close -unless it is on the edge and I also don't want to shoot down as it's not that interesting. This is also an issue on a wall. The short port doesn't help at all. So basically I stopped using it. A little extra working distance and the longer port for the 60mm macro means you are shooting at a shallower angle in this situation. I would also suggest diopters are not really needed with m43 1:1 lenses, on the 45mm macro the working distance is about 60mm from port glass at 1:1 - the diopter only eats into this. None of the options discussed so far would be great for a Giant Pacific octopus. Seems like better approach would be do macro dives sometimes and CFWA others?

I suspect you'll find the smaller range challenging with the 30mm macro lens, the field at 0.5x is 34mm wide which is about right for a 20mm nudi and you need to be 25mm from the port to do this. The 60mm will let you capture 10mm nudis with reasonable working distance and adding the MFO-3 will get you subjects about 500mm long at a maximum - it only focuses out to 1.5m, The post I linked above showed a shot of a trumpet fish about 500mm long and EXIF reported the lens was at infinity. The best option probably varies with whether you are mostly shooting small things or leaning towards mainly larger subjects. If you mostly shoot bigger something like a 12-40 in a 170mm dome would do well or a CFWA setup of some type. If by octopus you mean giant pacific octopus, the MFO combination won't get you there as you'll be too far away. But for subjects between 10mm and 400mm the optical quality with 60mm/MFO3 will be great and better than what you have with the 12-50. The 30mm macro will be slightly better for big stuff, but will suffer compared to the wider views from the 12-50.

Even things like my Atomos monitor has a single button that you need to hold for 5 seconds to turn off, then there's the lights that need endless combinations of short and long presses to change settings. Are they trying to save money on switches? very annoying.

I've used the 30mm a little around Sydney, a couple of things to note with it. First it's sharp and AF is snappy, however the practical limit for magnification is about 0.5x, the working distance is very small, it's about 25mm from the port at 0.5x, which can make approach and lighting a challenge. I'm not sure what the subjects around Vancouver Island are like - are you thinking most of them are on the larger size?

I do it's the neoprene bag the lens came with, it doubles up to keep the lens from drying out till I get home and soak it in fresh water. I'm planning to see if I can find a neoprene sleeve and cap that's more stream lined for longer term use

some pics, first the docking adapter on my float arm second the MFO3 mounted. You have a similar adapter mounted to the port to accept the bayonet mount, line up the white marks, insert then turn till it clicks. You can see it is a big lump of glass. Roughly same size as 60mm macro port. Honestly if you are just boat diving a quality flip adapter will be easier to use, just doesn't seem practical for me when shore diving from rocky entries, which is why I went with the bayonet.

Alex Mustard used it on a flip adapter, so it will work. I found it fine to carry in cargo short pockets and went that way as I will use a lot at home where I am making sometimes a little rough shore entries and exits, but from a boat the flip will be fine I think as long as its fairly robust. Here is a link to Alex's review. also I replied to your original post asking what to use:

IMO the very best thing you can do for Lembeh is buy a Nauticam MFO3, I went there last September and used it quite a bit for larger subjects in combination with a 60mm macro which is what you want for smaller critters. It increases you field of view to about a 35mm lens. With this you can get both large and small subjects on the one dive. Here's my report on using at Lembeh: and here is my trip report to Lembeh: I used the MFO3 on the Nauticam bayonet mount and kept the lens in a cargo shorts pocket. At home in Sydney I have it mounted on a docking adapter on a float arm which works well. It's a fairly big lump but manageable. At least out here in Australia the MFO3 is cheaper than a 30mm macro plus macro port - assuming Nauticam housing, but you have to buy bayonet adapter, bayonet ring and docking adapter. Definitely worth it for the flexibility and image quality is very nice.

Your recollection is correct the attachment point on the WWL or adapter ring has 3 blades. The locking pin drops into a recess to prevent rotation. The only way these bayonets work is like with like. The way to use a WWl-1B is to mount a Nauticam bayonet assembly to the flat port. The only way to mix and match a Nauticam wet lens to another bayonet system is with the first WWL-1 which has an M67 thread allowing other bayonet rings to be threaded on, this may or may work well depending on how the spacing of the rear element ends up in relation to the flat port glass. The OP has a WWL-1B and the only way to use this with Marelux is to use a Nauticam bayonet mount on the the flat port, unfortunately the WWL-1 doesn't work well with available Canon zooms. I don't know if you have purchased anything yet but the ideal situation would be to compare costs using your WWL-1 with other systems such as the Nikon 24-50 or SONY 28-60 against buying a new port wet lens under the Marelux system to use your 16-35. Of course if you already have the R6 that's a different story. If that's the case I still think you should look into finding a second hand 8-15 lens, there will be plenty of them available in Japan and they will usually ship internationally. But the ideal situation will vary somewhat with what you like to shoot. If you were shooting mostly at the wide end of your WWL-1 with the R50, the 8-15 would be a good choice. But if you were using the long end a lot as well, going with a WWL range lens would be better. On the choice of wet lens, the Marelux 130 matches the WWL-1 it seems with the same field which is just slightly wider than a 14mm rectilinear in the horizontal field assuming that the Marelux has similar barrel distortion to the WWL-1, Marelux 110 seems a little narrow to me as the bare lens by itself is as wide if not a little wider in the horizontal field.

I basically no longer use tracking UW, it seems to work quite well on the eye of a bird but not so well UW on my system. I suspect this around the camera not being trained on your subject, so whether AI subject recognition is on or not is one thing, but if tracking is enabled without it the camera still needs to remember what it was focusing on and follow it. It probably has recovery features if it loses it, but can only do so much. So this means i have to place the small spot where I want focus and fire when it achieves focus, works well as long as the subject doesn't suddenly sway due to surge. It takes some practice to achieve this and I've found hand held macro photography on land to be a decent training ground.