Chris Ross

Believe winds are up in September from the south so getting to the resort and the out to the dive spots not as pleasant, but improves by October. Strong south winds may impact which sites they go to. I've not been but a friend of mine who has been many times goes to this place: https://papua-diving.com/ . He does a lot of dive travel and has been there a number of times, Cape Kri is their house reef. I'm planning on going next year.

The leak detector is quite simple, just a circuit that detects increased conductivity when you bridge the terminals with a little water, it would have negligible current use unless it activates. So I would think quite safe to leave the battery in place. Regarding the vacuum circuit, the Nauticam system is quite good but the system you have also works. You could install the the Nauticam circuit probably fiddly but possible, though installing the LED my be a little tricky, you might be able to use the LED window on your current housing for this purpose, if the LED supplied fits. It will depend if you can find room to mount all the needed components. You would get similar functionality to the Nauticam system with a Vivid Leak Sentinel and it would be a lot easier to install as it only needs a free M14 or M16 port, you would likely install where you have your current vacuum valve.

It's going to be hard to tell what's happening from photos, obviously the mechanism is partly hidden. You would need to turn the knob back and forth and confirm which parts move inside and feel how things move in there. So confirming that the knob turns the camera rear dial that would be the smooth knob directly below the vacuum valve in your photo, outlined in red here: The parts outlined in blue look like the parts that control the two dials and they would be the parts you would be looking to remove. Looking at the following view of the housing it appears this might be the drive train outlined in red: You would need to confirm that by checking if the shaft rotates when you operate the knob. Before you start pulling it apart it is probably best to confirm if you can buy the needed parts, perhaps you could contact Backscatter or Reef as they seem to to service Nauticam gear to see if they can provide the needed parts and assistance with how to install them.

Most sources say that the vacuum light goes green at 200 mbar which is about 5 in Hg. 15 in Hg is probably a bit too much and I would stick to around 5". Regarding fogging, aluminium housings are generally a lot less prone to fogging, but it can still happen. It depends on how humid the air is when you close the housing. 4°C is quite cold so you would want fairly dry air inside the housing to guarantee it won't fog on you. For example if the air is 20°C and the relative humidity 30% then the dewpoint is right about 4°C. This chart allows you to estimate the dewpoint: https://www.hardwareinterviews.fyi/t/why-does-condensation-form-on-the-outside-of-cold-glass-on-a-hot-day/19/2 Start at dry bulb temperature and go up vertically to the relative humidity (blue line) then horizontally across to the the 100% RH curve. This provides the dewpoint temperature of the air and when it cools to that temperature, water starts to condense. As to what to do about it it would depend on your atmospheric conditions on the day the hotter and more humid the air the more likely it is to fog. An easy way to help is to purge the housing with air from a scuba tank which should be bone dry immediately before closing up. The vacuum will also help a little. Aluminium housings normally don't fog as the metal gets cold quicker than the glass and the moisture if any will condense on the metal walls. I recall that some triggers switch themself off when the camera is off, There was a post on this topic a little while back- possibly on Wetpixel? Can't say for certain about the nauticam, but I recall they have a very long battery life.

Cameras, lenses, adapters etc you can generally price looking at Ebay auction results, filtering for completed sales. You could also look at Keh.com or other second hand stores and ask for a little less than them as they offer warranties on items they sell. Directions for doing this on Ebay here: https://litcommerce.com/blog/how-to-see-sold-items-on-ebay/ I usually look for completed items. Another factor to consider is that camera specific items like housings will realise a lower % of new price than items like your 45° viewfinder which can be used on nearly any Nauticam housing. Similarly for strobes, domes and WACP which are more widely able to be used regardless of camera brand/model.

You might need a new o-ring for the knob and you should use new c-rings if you disturb any, they are mainly used on button shafts to secure them to any internal levers used. Nauticam housing are known to be difficult to to service due to the complicated mechanisms inside. How you deal with it will vary depending on how accessible the knob is and whether you need to remove other internals to access the knob itself. Often the motion is transmitted to the the camera knob by a gear train. This means that the stiffness my be the knob itself or there could be an issue with the gear train and internal wheel. This is a snip of the internals of the A7RIII housing: I assume you are referring to one of the knobs shown here, either exp comp or rear dial (the knob for rear dial only just appears above the housing in this shot). The mechanism for this dial is buried beneath several other mechanisms and it is hard to tell from this image just what would need to be removed to allow it to be serviced. It appears the drive for the rear dial is transmitted by the shaft at the top of the image. On my housing the drive knob is in a spring loaded assembly with cap screws securing it to the housing body. I highlighted what appears to be the drive wheel for the rear dial and you might be able to remove that assembly to check it. You would need to examine it closely to determine how each component is secured and disassemble in the correct order. The tools required should be straight forward, the difficulty is removing other mechanisms which might be in the way and re-installing them correctly.

Yes I'm using the Metabones and it seems to work in C-AF, haven't tried the tracking modes though. If I recall correctly I downgraded the firmware to get it working on a big Canon Tele lens. AF seems quite rapid with the 8-15, haven't used it anywhere that would require any sort of tracking though.

Is the knob difficult to turn with the housing empty? Or only when the camera is loaded?

Yes that is correct, the 8-15 used a 30mm extension with the 140mm dome, I have an old version of the Canon EF port chart open in my browser now. I also opened the new one and it is now one long page instead of being divided into pages like the old one and cuts off suddenly in the middle of page 7 of 9 and the listing for the Sigma 14-24 is cut in half. Seems like the obversion to pdf might have failed somehow and it cuts off a few Zeiss lenses, the Tokina 10-17, Nikon 10mm as well as the 8-15 fisheyes and the Sigma fisheye.

Thanks!, lighting is pretty standard 10 and 2 lighting close in and a bit behind the port. They are quite small in the range of 35-55mm total length, the way to spot them seems to be that they are slightly out of sync with the surge.

One of the critters unique to Sydney divesites is the Sydney pygmy pipehorse, they are quite small and cryptic and apparently restricted to the coast south of Sydney NSW. They are so cryptic that it takes real experience to find them and they can "disappear" seconds after you have been shown precisely where one is. Lucky enough to dive recently with a diver who routinely finds up to 40 individuals on a dive at The Steps, right at the entrance to Sydney's Botany Bay and got a lot of photos of individuals with varying colouration. They range in length from 30 to 55mm long and colour varies in shades or reds, pinks, white and green-brown shades. To add to frustrations they sway just a little out sync with the surge and squirm a bit following food items, plus their eyes also swivel rapidly and there's plenty of shots where the pupil can't be seen as it is looking behind.

Processing time for me is quite variable, the longest step is if the shot needs backscatter removal or other re-touching. But a properly exposed photo should mostly be done in a few minutes IMO. what step is taking the most time? I would suggest if you are fussing over a particular aspect stop and do a different shot or walk away and come back to re-visit it later. It can be easy to get caught in a vicious cycle correcting one aspect only to undo good work you've done elsewhere. One thought is to post a photo you are struggling with and do a how would you process post inviting others to process it and tell you what they have done. My workflow consists of levels/colour correction followed by contrast adjustments - I use luminosity masks in full photoshop. I generally end up with a levels layer and 2-3m masked curves layers The luminosity mask allow you to adjust shadows, highlights and midtones separately. With this process step one is backscatter, the luminosity mask is prepared from the image so removing backscatter later can cause problems

to be fair they are all cropped somewhat, the corners are not perfect, but there is also little of interest down there and when viewed as part of the whole frame totally not noticeable. here is a centre and corner 100% crop from one of the images at 12mm FL, for those who would like to indulge in some pixel peeping. Both are approx 800px wide 100% crops. you can see the corners improve quite rapidly away from the extreme corners and they do look better than the little Panasonic 8mm fisheye lens. At 8mm the corners seem slightly better. 100% crops out of most cameras of course look a little ordinary.

Thanks Justin and to answer question, no not as yet, my problem is that on local dives which is 90% of my diving I rarely shoot more 0.5x, most of the critters I manage to find are larger, even the pygmy pipehorses while small don't need that much magnification.

Took the OM-1 plus Canon 8-15 rig for it's first dive off Sydney on the weekend a couple of deep sites about 500m offshore. Rig is noticeably heavier than using the 12-40 plus Zen dome and I'm now running about 1.7kg of buoyancy to get it very slightly negative, previously using about 0.75 kg. Here's some samples from the dives, First up some Giant Cuttlefish: and some colourful sponge gardens

Welcome onboard and thanks for persevering, don't know that we have had too much problems reported by Captchas. On security it's not so much [protecting anything posted, here, but on Wetpixels many scammers and bots tried to signup, they try to scam people on the classifieds forums or try to harvest passwords which sometimes will be the same as other social media accounts and get up to other mischief. Best to keep them off the site.

A simple curves adjustments would do wonders, for most of them just pulling the curve down makes a big difference.

The main point of considering this this lens for UW use seems to be to allow shooting small to medium fish that often move quickly that won't allow you to get in close to shoot with conventional lenses. If that is your interest, how useful it is I would think depends on how quickly it will AF. Many macro lenses are not so good with AF if they need to move focal range extensively and it seems to be related to the wide focal range which takes time to cover. A prime example for me is the 12-40 f2.8 Olympus lens which snaps to focus very quickly while the 60mm macro takes a leisurely cruise to get there and seems more likely to hunt. As for 1:2, well if you want to fill the frame comfortably with a 40-50mm fish on full frame you need to achieve about 1:2, sure you can do that with a long macro lens but will it focus as fast?

Don't know what they use But I would comment using such lenses in a small dome wouldn't be quite penalty that you see with shorter zooms and it would allow an all in one solution, you wouldn't be wanting a big dome at all at 70mm. Likewise another lens to consider would be the Olympus 12-100 lens, I don't see anyone offering that as a possibility but apart from needing to make a zoom gear should not be too difficult to house. One anecdote I did not offer before on the 12-40 lens is an experience shooting Mandarin fish at dusk, they don't like light, so I tried a red filter but still didn't like it so I went to shooting without a focus light using the 12-40 zoomed in to 40mm and it was snapping into focus instantly - no comparison with the 60mm macro which would hunt like crazy in such conditions. I would guess that the 12-100mm would have similar performance. Part of this is the excellent optics wide open which helps AF work better.

I'm no video specialist, but I do know it pays to read the fine print on the video specs for gotchas. For example the A6700 will do 120p but it does this as a 1.58x crop from the sensor. the active stabilisation mode applies a 1.13x crop when activated as it is partially a digital correction. Also pays to check the available codecs and profiles and any limitations they may impose upon you - possibly things like processing overhead. You normally need to dig into the specs a little more deeply to find these limitations. Also if stabilisation is important to you, the in-body stabilisation of the smaller m43 sensors is generally better as the smaller sensor has less mass and is easier to stabilise as a result. For example the GH-5 II has 6.5 stops of stabilisation.

I'm not saying that you imply anything I'm simply seeking an explanation of the apparent contradiction. They claim that distortion one way makes an object look bigger and the other way smaller and it seems you disagree with that premise.

I found a preprint of the article here: https://www.geomar.de/fileadmin/personal/fb2/mg/kkoeser/domecalibration_preprint.pdf And in figure 3 on page 5 they have a diagram showing the UW part getting wider/narrower as the position changes as was stated earlier in the article. I haven't read through it all or looked at the optics involved, but it looks like you are saying the authors are wrong. Can you say what their error is?

Yes just a matter of finding the right lens! I get the impression the tracking systems seem to work better on distant subjects like flying birds with telephotos rather than close in and busy. I'm wondering if you could somehow squeeze the Olympus 12-100 lens into a housing. Then you could stand back quite a ways, the 77mm OD would be tight for the Nauticam N85 port system. There's also the OM-1 Mk2 coming out which mainly claims improved AF and tracking features.

Nauticam has made changes to their extension rings introducing the type 2 version recently. I recently purchased a 35mm N120 ring (22135) from Scubapix, the Australian Nauticam importer for to use with my newly acquired Canon 8-15 plus Metabones for my OM-1. The main difference compared to the original version is the locking mechanism. The old version required you to swing out the locking pin, line up the ring push it in and turn. Then the locking pin was swung back in. The Type 2 has a an external lever that swings out to turn the internal lug ring to lock the port. See the photo below: The lever requires you to press the grey button before it will unlock with the red button, when you open the lever it turns the internal lug ring, quite similar to the locking mechanism for ports on the Nauticam housings. The port is mounted to the ring lining up the two circles and pressed in then the locking lever is closed, no need to turn the port. See the lever in the unlocked position below: The locking ring rides on three ball bearing internally and slides quite freely, you can see part of the mechanism in the photo below: The ring comes with a soft storage bag, spare o-ring and tube of lube. The other difference is that all of this mechanism sits tucked away and doesn't intrude into the ID of the ring. The minimum ID of the ring is set by the ID of the lug ring which is 110mm, so maximising the size of lens that could be accommodated. The type 2 mechanism is only found on the N120 rings. The N100 and N85 rings have not changed. That's it not much more to say about an extension ring. Nothing there to make you want to upgrade unless you want to use a lens with a large OD. Probably the only lens right now that would benefit from the large ID is the Canon 11-24.

Did you ever use C-AF + TR on the EM-1 MkII? I found it reasonably good at holding focus on things swaying in the surge. I've found the same function not quite so good on the OM-1, but the AI helps in certain situations. I'll have a try shooting with subject recognition if I can find suitably wriggly subjects on my next dive. I'm first to admit I don't do much fish shooting particularly with difficult subjects, plenty of small subjects swaying in the surge though. I'm not sure I follow your argument regarding magnification. If you match the scene by which I mean the subject takes up the same % of the frame then the magnification is lower on m43, because you are further away using the same focal length to allow the fish to fill the same amount of the frame. So if you have a fish that covers 9mm on the sensor in m43 you have to make it cover 18mm on the sensor in full frame by getting closer or using more focal length. Certainly if you match the composition in full frame you'll have twice the pixels representing the subject, but achieving that seems like it may be easier said than done. A more likely scenario seems to be the extra real estate gives you more wriggle room to frame your subject.