Chris Ross

Australian weather is not really seasonal, rather there are frontal systems alternating with highs moving across the country from west to East and the wind changes with these systems coming through. Having said that the centre of the high pressure systems moves north-south in winter/summer which changes the average wind direction, so the East coast gets more westerly winds in winter for example. So basically it is a case of being in town long enough for the wind to move around to where you want it, with seasonal wind directions favouring one site vs the other. You can find a wind rose (pdf file each month) in this table for Edithburgh: http://www.bom.gov.au/climate/averages/tables/cw_022046.shtml and Noarlunga near Rapid Bay: http://www.bom.gov.au/climate/averages/tables/cw_023885.shtml Here are location guides: https://indopacificimages.com/australia/diving-edithburgh-jetty/ https://indopacificimages.com/australia/diving-rapid-bay/ Edithburgh is hazardous in south - south east winds, while Rapid Bay is sheltered from those winds while Rapid Bay won't go well in North winds, but on average is more sheltered. You might want to contact one of the local dive shops, presumably you would want to rent tanks and weights and not travel with them, also in Edithburgh which is about 3-4 hours drive from Adelaide there is no dive shop so you would need to bring tanks from Adelaide. You can however get air fills at the service station in town. I used Dive Adelaide and they were very helpful. Final consideration in water temperature, it's dry suit diving (11-13C) in winter and into spring while it can get to 22° in summer through to about April. Do you want to travel with a dry suit or dive in a wetsuit?. It can get stinking hot in summer so a sauna inside your suit till you get wet. All things considered I would go in April weather tends to be calmer then and avoid being there in School holidays so you can be a bit flexible with accomodation, you would probably want to over night in Edithburgh when you travel out there. Then pick your days at each site according to the weather, you can generally get a good idea 4 days out from the BOM website and swell forecasts: https://swell.willyweather.com.au/sa/yorke-peninsula/edithburgh.html Probably want to avoid long period swells . While you are in the country you might fly in and out of Sydney - go diving there for weedy sea dragons. Again it it's a matter of timing for swells and wind.

Thanks everyone, It's pleasing this has come along so well and that so many people have come across. I would say to contributors, the best way you can help move the forum along is word of mouth, more people and more points of view and contributions will help the site along. So if you happen to be talking to people about UW photography point them in this direction!

This is not surprising as if you look at tests you'd find the Oly 12-40 would be crisper in the centre than the 28-60 kit lens. Also a 24mm equivalent lens is not that much of a test of dome port optics. The WWL is not going to make the centre sharper, but provides better edges at wider f-stops than you could get in a dome. For shooting sharks the edge sharpness is less important. I use the 12-40 in a Zen 170mm dome and really like it for temperate water diving, what I really wish for would be a 10-40mm lens with same close focus performance.

The calculations are based upon the Nauticam port chart and the diagonal field of view they list. All the calculations do is estimate the horizontal and vertical field of view based upon the reported diagonal field of view. So on this basis the calculations are only as good as the fields provided in the port charts. The calculations are done for a number of projections as the horizontal and vertical fields are different in those projections at the same diagonal field and we don't what projection the Wet lenses are. This happens because the corners are stretched more or less in the various types of projections. The short version is if the calculations are incorrect, so are the port charts, but they are only applicable to the port/extension combination used in the port charts. A complication is that some domes are not full hemispheres. As Massimo points out the maximum field of view of the 180mm dome based upon geometry is that of a 16mm lens, however if you look in the port charts this dome is recommended for the Olympus 7-14mm, a 14mm full frame equivalent lens. The only way you do this and not vignette is to place the entrance pupil forward of the optimal position. In fact the issue of correct extensions is a bit of a red herring herring for the purposes here. What we are trying to do is compare reach of different combinations. Reach for example is about whether or not you can fill the frame with a shark that doesn't let you get closer than 3m for example. You don't need calculations done to 3 decimal places to check this, what you need is consistent calculations and in the case of not knowing the projection a way of cross checking. We can't compare every combination of extension and port size all we can do reasonably is compare recommended dome/wet lens/extension. Even if you are out a bit in extension it's not going to really change the answer as we are doing a relative comparison and extension change that still has reasonable image quality is not going change the field enough for you to decide differently which lens has enough reach for you. As Alex Mustard has pointed out before, this is only part of the equation - a fisheye projection provides a different impact to the image with close focus on the central subject causing it pop out and causing sharks to look fatter as examples. However if the shark is too small in the frame that's all moot, when you need reach you really need it and this discussion is about getting that reach while minimizing the loss of field of view if you also want to take some wide shots on the same dive.

Prevention is better than cure. On the boat keep the port wet with a neoprene cover till you can rinse it. When you get the housing back home or somewhere you can soak it give it a good soak then blow all the water off and dry off and polish with a micro fibre cloth . Basially avoid water evaorating from the surface. The water marks are not usually a deposit but tend to be bonded to or etched into the surface which i why they respond to polishing.

This table shows calculated values for fields of view diagonal/vertical/horizontal. If you want to compare coverage or reach I would suggest comparing horizontal fields is probably best . Not the same picture of course but is probably best for comparing how the lenses would go for example shooting a shark. The top 4 lines are rectilinear lenses. Then follows 5 ways of calculating the WWL coverage with a 28-60 lens. Stereographic projection seems closest to right as using a constant focal length multiplier to get the fisheye equivalent focal length it comes closest to predicting the full zoom diagonal field from the widest field multiplier. The equivalent focal length I'm using is adjusted to get the formulas to match Nauticam's figures for the WWL diagonal field from their port charts. Equisolid, equidistant and stereographic projections are reasonably close together predicting the horizontal field while Orthoganal and rectilinear are much further apart. T To demonstrate how far out the rectilinear formula is, I used the 0.36x factor for wide and full zoom it while it predicts the wide zoom it is 30° out on full zoom. I think the Sterographic projection is probably reasonable to predict the reach of the WWL to compare with the rectilinear lenses. Various caveats apply such as field being reduced at min focus distance etc, but it should be good enough to compare the reach of the various lenses.

Don't know what it will be like on the Z8, but on my OM1 which has one of the newer larger EVFs the edges are fuzzy with the original 45° viewfinder, which includes some status info. The newer ones are preferred with the new viewfinders. Mine is a carryover from the old housing, but if I were to buy new I'd spend the extra to get the best view. The 0.8:1 is designed with a wider view more mirrorless cameras specifically to include the information around the edge of the frame. This video might be helpful, there's a lot of bakground and it gets into the meat of it about 8 min in. And starts talking about the 0.8:1 10 min in. Alex says he prefers the 0.8:1 model even for the SLRs.

Welcome Aaron, good to see you here!

I have the lens but don't use it a great deal, I did use it a number of years ago in a 170mm Zen dome for whale sharks. It thought the results were reasonable, shooting it at f8. Shot below is 1/100 @ f8 ISO400. This shot is at 7mm, it is reported to be better at 8mm. If I was buying again I would likely get the new Olympus 8-25mm. It is also reported to be better in a larger dome such as your 200mm dome.

Nice shots against the colourful wall growth. Our Eastern Blue Devil prefers to stay under overhangs and in caves.

Well I'm going to cheat a little as well, my dive trip this year in November fell through due to the Ulawan volcano going off and forcing cancellation of my connecting flight from Port Moresby to New Britain . So I'm going back to my Nov 2022 trip to Rowley Shoals, which I first booked for 2020 and was postponed twice due to the pandemic. Rowley Shoals is 300km offshore from Broome in West Australia on the edge of the continental shelf. The corals out there were in great shape and on some days the water amazing clear, we had at least 50m of vis on some days. These two frames were taken about 30 seconds apart at 18 and 20m and in the second frame a sunball is apparent at 20m depth. This one is at 20m depth: This snapshot shows how clear the water was, taken at another site called Waypoint 3043, I'm hovering at a depth of 12m and the bottom is at about 25m. Visibility was at least 50m. The superb vis and isolation were what made this site special. We were on a boat with 18 passengers and the only divers in the water. You can only travel out there in October-November each year. Shots with EM-1 MkII in Nauticam housing, Panasonic 8mm fisheye, INON Z-240 strobes.

Welcome Luko, good to have you here, We'll ask the etam is the flag can be changed I had a look and couldn't see anywhere to change flags.

I use something similar on liveaboards for example, mine is collapsible one with a hard lid, purchased at K-Mart, it's big enough for my Nauticam m43 rig with a pair of strobes, the arms poke out, but that;s fine. I've used it with a 4"and a 170mm dome. Some negative and positove experience with the cinebags here: https://wetpixel.com/forums/index.php?/topic/66566-cinebags-underwater-cb70-square-grouper/page/2/

Adapting Nikon lenses is more problematic, due to the the variety of types on their AF lenses. It is not currently possible to adapt older screw drive lenses which rules out the tokina 10-17 for example. This link explains: https://briansmith.com/where-are-the-nikon-af-lens-adapters/ Which particular lenses were you wanting to adapt? AF performance also varies depending on the lens in question. A couple of the available adapters like the Viltrox have a big tripod foot which interferes with mounting in a housing. Here is a guide on Nikon AF adapters: https://briansmith.com/nikon-lens-adapters-sony-e-mount-cameras/

I had the same issue it would do it on or two lenses and the others were fine. As i recall the repairs weren't too expensive at the time, but turnaround time is currently a while I believe. In my case it was the camera body which was the problem. They have a support number you can call and talk to them they can tell you if you need the lens as well as the body or not.

Hi Al, welcome to another Sydney-sider!

What camera?, I recall having an issue with my EM-5 MkII a while back. It had a component they replaced to fix it. I looked it up and it was a frame contact mount unit that was faulty. It is needed to tell the camera a lens is attached. It was back in 2017 so exact details are vague, but it sounds similar to what you report.

The steps divesite where I took this is basically my local divesite and is arguably one of the best spots to find these animals. So if you get to Australia let me know, I'm sure I could find you one - Weather and swells permitting of course!

For full frame cameras it allows zoom between full frame fisheye(180° diagonal) and something approaching a 24-28mm rectilinear lens across the horizontal axis - depending on what lens you use it with. Previously you could only get this on APS-C with the tokina 10-17 and with m43 with an adapted 8-15mm lens. This is otherwise something you can't achieve that on full frame and is a very useful range for wide angle shots covering reef scenics and CFWA plus some chance of zooming in for sharks and pelagics which are too distant to shoot with the 180° diagonal fisheye.

I actually priced out an Isotta setup for a 60mm macro and 8mm fisheye in UK and the prices seemed quite good. An EM-1 III would also work very well, I've had the EM-1 II for a long time and just started taking the OM-1 UW. The main upgrade is faster AF and drive rate which is great for land based focus stacking but not so applicable UW. So It's not a great difference going with an EM-1 III if you can get it at a good price. I only went UW with the OM-1 as I had a intermittent issue with the EM-1 II and rather than sourcing another EM-1 II I got the housing for the OM-1 I already have. I would guess if you are on a budget you would try to get a single dome for wide angle, or with the Canon 8-15 or Tokina 10-17 you could get a fisheye all the way through to about 26mm full frame equivalent (for the 8-15) in one lens/dome so it would be like combining a fisheye with a 7-14 lens, only difference being the barrel distortion which reduces quite a bit as you zoom in. But it could all be used behind the Isotta 4 1/2"dome. The trade off being buying a Metabones adapter.

One question we didn't ask is which strobes you use, strobe power also scales with aperture as you generally need to stop down more with larger sensors. F8 is perfectly adequate on m43 while you are looking at f11-13 for APS-C. Shooting macro with the TG-6 doesn't need so much strobe power as you are so much closer and the lens is faster as well.

The Weedy Sea Dragon is one of the iconic species on divesites in SE Australia, they are quite big animals, around 350-400mm long or so and are really a bit too big for my Oly 60mm macro lens, I was about 1m back for this shot, which is a lot if the visibility is not great. So this is more of a snapshot, taken with quite low strobe power and a bit of cloning of backscatter. This one is a male carrying quite fresh eggs, it was just hanging in a clearing between kelp stands.

No Problem, I have the App - Fishes of the east Pacific which seems quite good, it's free. https://apps.apple.com/us/app/fishes-east-pacific/id494644648

There's lots of different barnacle blennies, this is possibly a Panamic barnacle blenny.

I'm not sure I'd want to travel with a 250mm dome. You could also look perhaps at the 8 1/2" acrylic dome from Nauticam, it's a step up from the 170mm dome. You could also consider one of the Sea and Sea domes and just change the lug ring over to Nauticam. They have a 210mm acrylic and a 200mm glass dome you could look into. How much of an improvement you see with a bigger dome is most likely going to depend on the lens in question, the Sony rectiliear wides seem to perform quite well in smaller domes, though the 12-24 might be stretching the friendship anything smaller than a 230mm dome. https://www.seaandsea.com/ If you click on the instructions they include a procedure to change dome to a Nauticam mount. on the question of fisheye I would expect minimal improvement with a bigger dome once a certain minimum size is passed and placing it a little too close to the glass may indeed lose a little field of view, but there are plenty of people using fisheyes with the entrance pupil closer than optimal point. A prime example is the ikelite dome port for CFWA, the factory recommended setup has the entrance pupil well forward of the centre of curvature. They certainly seem less sensitive to the problem. This link shows some shots with a Nikon 8-15 and the ikelite CFWA port: https://www.ikelite.com/blogs/reviews/nikon-8-15mm-fisheye-compact-8-inch-dome-underwater-photos