Chris Ross

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.

I would ask what you are missing out on with your current system , cropability is the only one that seems to stand out to me. Having said that I get plenty of perfectly usable images with up to 50% cropping out of the Olympus. I have used the EM-1 MkII for quite some time and now I'm using the OM-1 initially on land and now have housed it underwater. I've found the AF to be very good on both cameras, but the OM-1 is certainly a step up in AF capability. For example at high magnification on the 90mm macro it would lock focus where the EM-1 MkII could not, probably pointing to improved low light focus capability. But it seems AF is not a limiting factor with the EM-1 MkII for your uses? I'm not sure I get your argument on this item though: Field of view is field of view, you just need to have the same equivalent focal length on both systems, to get the same reach and field and ability to frame comfortably. If 80mm full frame equivalent is enough for you the 12-40 olympus lens is very sharp right from wide open and focus is extremely snappy, it just locks on and as a bonus will focus very close allowing about 0.3x focusing right on the dome. Macro lenses as a rule will generally be slower if for no other reason that they have a very wide focal range to work through. the 12-45 f4 is a slightly smaller package which has similar to the 12-40. Regarding resolution, underwater shooting through a significant amount of water is a great leveller. What ultimately sets your resolution is pixel size and the OM-1 20MP sensor has 3.3 micron pixels while the 61MP Sony has 3.6 micron pixels, so pretty much a wash for pixel size with a small advantage to the m43 sensor. The other consideration is depth of field the same fish comfortably framed the same way on full frame has less depth of field than a m43 frame. You can shoot m43 at f8 and get the same depth of field as full frame at f16. This also means with the same pixel size you are deeper into diffraction in general on full frame. In general you will be shooing with a wider f stop on m43 and this means that you need less strobe power which is a consideration if you are backing off and using longer focal lengths for skittish fish meaning faster recycle times. Depth of field may be important for example in trying to do ray counts on a small fish that refuses to let you get parallel to it. Diffraction starts at f7.1 on a 61 MP sensor but you do need to stop down quite a bit more before it starts to impact resolution the difference is you could probably shoot at f5.6/8 on m43 all the time and be effectively diffraction free while full frame you might be f11 at minimum. This is probably more of a leveller between the formats than a clear advantage for m43. To me this means why go to the expense of FF?

It is quite possible to "vacuum" a housing together, most housings you would need to open it in flight and close it up again. Housing clamps only need to be tight enough to pull down the housing to make an initial seal and the clamps may or may not be able to resist a small movement in the back of the housing due to internal pressure. UW they rely on water pressure to keep them closed tight. To explain a clamshell style housing if you fly with it closed with the clamps in place the air inside tries to push it open at altitude but the clamp stops it opening, it might move a bit but, not enough to unseat the o-ring. But a housing with a flat back and a surface o-ring like an ikelite even if clamped only needs to lift the back a tiny amount to lose o-ring contact and lose the air inside, but when the plane lands external air pressure starts to push the back closed and you are left with a vacuum inside. But if you have a vacuum valve you can release the vacuum and there is no problem. It's also of course only a potential problem if you fly with a port mounted to the housing. For packing I often have the plastic cover on front rather than a port and I can do what I like as the housing won't hold a vacuum - o-ring or no o-ring.

Interesting post, it would be an ideal method for housing manufacturers I would think - all they would have to do is half fill their test tanks to try it out.

Don't forget UW red light is scattered much faster, the light should be a little dimmer - try both settings.

I've used a red focus light on land with both Olympus and Canon and it seems to work quite well, that however is shooting fairly distant subjects and there is contrast between subject matter and the black backgrounds. Have you tried reducing the brightness either on the light or taking it further away - one possibility is it is saturating the chip and as it's all red light it can't find anything to focus on.

OK Thanks, if you have google drive it's a good method you just have to set permissions to anyone with the link.

I haven't done the Murex deal but I know people doing it in a month or two. I went to Diver's lodge Lembeh when I did Lembeh a few years back and I would highly recommend them. They have as standard 2 divers one guide, though they now have a private boat scheme which may add to the costs if you are travelling alone. They will also pick you up of drop you off at other resorts. An additional consideration is they will dive the far side of Lembeh Island at the right time of year which has coral sites as opposed to muck sites being at the SW end of the island the trip around to coral sites is relatively short. In addition, food is good, accommodation comfortable and pricing reasonable. https://www.diverslodgelembeh.com/ also see their FAQ page about timing. I was there in November just as the wet season was kicking off so it was drizzling a bit. Some critters are seasonal for example Ornate ghost pipefish are most sighted June-October. This guide may be useful: https://critters.lembehresort.com/ornate_ghostpipefish_solenostomus_paradoxus_c62.html Just type in critters you are interested in and it says where they are found and any seasonality.

The toslink connectors themselves will fit in a Sea&Sea standard socket if you shave the corners off the square connector that surrounds the round metal piece which holds the fibre - just trim carefully with a Stanley knife. I've purchased a toslink cable in the past to get me out of trouble.

Interesting - if I had the RAW file I'd like to have a go using my method using Capture One.

Min focus is about 20mm from the port glass. I have the Panasonic 30mm f2.8 macro which I use occasionally UW. I find that max practical magnification to be about 0.5x for UW use. The Panasonic lens has very snappy focus and is better than the 60mm macro in that regard.