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ChrisRoss

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ChrisRoss last won the day on March 28

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About ChrisRoss

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    http://www.aus-natural.com

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    Male
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    Sydney Australia

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    Australia
  • Camera Model & Brand
    Olympus OM-D E-M1 MkII
  • Camera Housing
    Nauticam
  • Strobe/Lighting Model & Brand
    INON Z-240

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  1. That's a good approach , having a slightly negative housing is not a bad thing, much better than positive.
  2. Total UW weight =800-50+250= 1000 gr. The two Nauticam arms are 1020 gr, so 20 gr positive, however you also add 6 clamps and two ball arms which I think are around 650gr in total maybe a little less in water so you might be 500-600 gr negative when you add them in. You probably could use two of the big INON or Nauticam floats with that setup depending on the weights of your clamps. An alternative might be to add 2 INON ML arms at 210 gr each and be 100-200 gr negative. Or you could consider the Kraken adjustable arms if you want to get perfectly neutral.
  3. the long clamp goes in the centre between the two arms - it allows the arm to fold completely so the two arms are parallel. First though get your weight in water - you could have a different mixture of arms.
  4. The trick with the mega floats is to use long clamps - I have the small mega floats used together with plain non-float arms for my macro setup and find it works well. I can't use the same setup with my dome as it is too buoyant - domes tend to add some buoyancy to the system compared to macro setup - the bigger the dome, the more buoyant in general. The big mega floats have a lot of buoyancy and you generally need to use two of them for symmetry. So with either of these choices you are looking at 1.2kg of buoyancy as a minimum.
  5. Thanks for that, Nudis can be found in all sorts of habitats and generally on or close to their food source - in Sydney that is mostly on rocky reefs where they feed on sponges, tunicates, hydroids etc. Apparently nudis in this part of the world are bigger than in other areas like the Caribbean and they can be readily found on the rocks. The diving in Sydney is excellent so plan on doing some dives there - the visibility is quite variable and the dive sites are subject to swells so you can't just dive anytime. The water is also cold, it's at its warmest of around 20°C in April-May timeframe and dive conditions are mostly good. Plenty to see underwater including weedy sea dragons, giant cuttlefish, sea horses, nudis etc.
  6. The issue as I understand it that while you can fix a Raw image in post for colour temperature problems, video editing does not have the same latitude for correction as you are generally not starting from a raw image so you need to be close. Good sensors are one thing but if the camera lands you too far from the goal posts you might struggle somewhat. I guess filters are an option particularly if you are shallow. Video is really not my thing I know enough about it to be dangerous- if I might suggest asking in another post about current performance of the Sony sensors under the conditions you are talking about and recommended approach. I don't have a feel for how close you need to to colour grade in post. I find it odd that the 28mm f2 and 35mm f2.8 both are listed as working with the WWL-1 while the 28-70 f3.5-5.6 lens is not as that would be a ready solution for you. You might also consider the Zen DP-170 N120 dome port as an alternative to the Nauticam port.
  7. I'm not sure what you hope to shoot with the 35mm lens it's effectively a 45mm normal lens behind a flat port, you can as you say add a WWL-1 but that is a big chunk of glass you keep to keep somewhere when it's not attached to your port. It should be fine for medium sized fish around 300 - 400 mm long I would think, however it does not focus super close and only achieves 0.12x magnification, so a 290mm long subject would fill the frame horizontally at minimum focusing distance. I assume you are looking towards primes so you can shoot wider open? If I was looking at lenses in that range I'd suggest looking in the direction of the 24-70mm f4 lens which goes with the 180mm dome a fairly compact affordable solution which gives you more reach when you need it for smaller fish and wide enough for a man sized school of fish - but not really wide enough to stray into the issues with poor corners in wide angle domes. Or you could look at the Sigma ART 24-70 lens which achieves 0.34x magnification filling the frame with a 100mm long subject. As you previously used an RX-100 I'm sure you are aware of the limitations white balancing Sony cameras underwater.
  8. The WWL-1 port chart is here: https://drive.google.com/file/d/1Cyk7BxeB8sVcmnoG03Up4yilm0i62xFg/view these lenses are not listed as yet - the WWL-1 requires a 28mm equivalent lens at the wide end so the Sony lens may work. The Nikon would need to zoom to 28mm to stop vignetting and may also work. You would need a flat port of the right size available which placed the front element up close to the port glass - Nauticam don't list these lenses so you would need to work out the appropriate port yourself if you wanted to test the setup. The WWL-1 is mainly specified with compact - through to APS-C system lenses the only full frame Nauticam list is the Sony 28mm f2. I'm not sure why this is But I expect they would list more lenses if they worked for full frame cameras.
  9. Hi Apocolibri, If I may suggest, sometimes the point doesn't always get across well in printed format on a forum. Massimo makes some valid points as do you. To be strictly correct the Olympus 100-400mm lens has the field of view of a 200-800 on a m43 sensor and it is strictly equivalent to a 200-800 f10-12.6 lens on a full frame at least as far as depth of field goes, but has the advantage of being physically a f5-6.3 lens for light gathering capability. The implication of this is subject isolation using depth of field is more difficult on m43 lenses due to the greater DOF with smaller sensors at a given subject framing. It means the image looks like it was taken with an 800mm f12.6 lens, which would weigh about the same if one was made as the weight is set largely by the big chunk of glass up front. For a tele lens a 100-400 of a given maximum aperture and construction/optical quality will weigh about the same whether you design it for full frame or m43 as the diameter of the front element is set by focal length and f ratio not the image circle. Where m43 gets a real advantage is wide lenses as they can use smaller front elements and internal elements as they project a smaller image circle and also being mirrorless are not constrained by need to use retro-focus design to accommodate a mirror box. For example the Olympus 12-40 f2.8 has a 62mm filter while the near equivalent 24-70 f2.8 from Canon uses an 82mm filter. Optically they only need a 29mm diameter front element. This makes the m43 wide lenses significantly more compact. Olympus like any other company is sometimes a bit liberal with their specification claims - the 0.57x max image magnification for instance includes a crop factor which kind of defeats the purpose of getting more magnification. The point of all this is that simplistically the crop factor gives you 2x reach but after that it is not really fully equivalent to full frame as it's no different to cropping a full frame sensor - the magnification is lower with the same subject framing so depth of field goes up and less light is gathered due to smaller sensor area sensor area so image quality suffers somewhat. Most people are happy to just get the reach and it's good enough for many people. Having used both full frame and m43 super teles - the images are certainly different, getting a nice smooth background is harder in m43 and you have to be a lot more careful with your framing and background selection to stop the background going ugly on you.
  10. Seeing as how you have all of your gear - assemble it with camera and lens and weigh it hanging off a luggage scale in a tub of water - completely submerged. Your YS-D3 is listed as -20g underwater (i.e positive bouyancy) and the Weefine light at 240gr UW. Add up all of the underwater weights paying attention to the signs and that is the amount of buoyancy you require. You of course also need clamps etc. which add a little negative buoyancy. I use a luggage scale - it's good enough just hang the housing off a rope or sling and let it settle and get the weight. It's best in a tub of water that is deep enough to fully submerge. Then select the float arms that add up to close to but not over the weight of your system - you do not want a positively buoyant rig - slightly negative is more stable. You can use 4 float arms or two float and two regular arms. INON provide a table of UW weight for all their equipment which may be helpful: http://www.inon.jp/products/armsystem/weight_table.html If I were to guess based upon my system I would say what you selected is too much buoyancy - but don't guess weigh it and calculate. It will be about 3% more buoyant in salt water - but that is normally within the margin of error of these calculations. If you use the Mega float arms I would recommend long clamps for connecting it to your other arm otherwise they won't be able to fold them to get the two arms parallel and it will limit how close you can get the flash to your housing
  11. Good topic Adam, - one thing not really mentioned about medication is that prevents seasickness but does not cure it. If you are going to take medication, take it 1/2 an hour before you get on board. Once you are starting to feel the impact it's usually too late. Interesting you talk about feeling ill in the water - I get seasick on boats and if I'm feeling a little queasy I feel instantly better once in the water - not that I've been snorkelling or diving in really big rolling swells, but I get surge on shore dives around Sydney all the time and it doesn't seem to bother me at all. Of course everyone is unique, but I always encourage people feeling sick on the boat to hop in the water. The other thing that can get you trough a rough patch till you get in the water is closing your eyes for long enough for the nausea to settle down. Lying down can help but you probably don't want to do it inside. Food can also make a difference - you probably don't want anything too acidic, greasy or spicey, so chugging back a big bottle of Orange Juice before hopping on board is probably not good as is travelling on an empty stomach.
  12. You could probably start here: https://www.stlfinder.com/3dmodels/zoom-gear/?page=2 There's a file for an olympus lens in an Aquatica housing and also one for 10-17 in a different housing - join the two together with the right length and it might save you some work. You would probably just take the internal dimensions for the 10-17 gear and the gear dimensions from the Olympus gear and join them together. This post may also be helpful: talks a bit about "assembling" the gear from parts in the CAD program
  13. A quick Google finds the only option being an EWA Marine bag housing - might be OK for splash work, Don't know if this is a newer model or not, but found older posts here: http://www.bmcuser.com/forum/blackmagic-camera/general-discussion/16779-no-underwaterhousing-for-ursa-mini-possible Indicates nauticam have no plans to house. You could maybe hire one from Hydroflex? https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwj5lczsxqvsAhWJ7XMBHYPgCG0QFjADegQIAxAC&url=https%3A%2F%2Fhydroflex.com%2Fequipment-rentals%2Fcamera-housings%2F&usg=AOvVaw2Vg3fkAOKjBEXVdBCrruPu
  14. The WWL-1 gives a 130° diagonal field of view (equivalent to 10mm lens) from a 28mm equivalent focal length lens so that is 10/28 = 0.36x. So that makes the 14-42 into a 5-15mm equivalent lens. The WWL-1 introduces barrel distortion - sort of semi fisheye so while it gives you 130° on the diagonal, the horizontal field of view is more like 104° rather than the 121° you would expect on a 10mm rectilinear lens so that would be more like a 7-21mm lens for the horizontal field of view. Fisheye lenses are similar - while they get a 180° diagonal field of view their horizontal field of view is only about 135°
  15. The fisheye can be housed in a smaller dome - on Nauticam their 140mm glass dome is recommended, but it can be used in bigger domes or the 4.33" acrylic dome. The 16-35 lens is the most demanding and to get good corners you need the 230mm dome. The Nauticam port charts list options to use the 8.5" acrylic dome and smaller domes but don't expect good corners at 16mm. The S&S correction lens is also recommended to help with corners. The reality is that housing a full frame camera is an expensive option and made doubly so if you want to house a wide rectilinear lens. Having said that it does depend a little on what you plan to shoot - big animals with bluewater in the corners should be acceptable. It's hard finding images that show this online here is one link which gives you some idea what to expect: https://uwaterphoto.com/?p=839 That link also talks about the S&S correction lens and shows the difference it makes. At top is a photo on full frame with a 170mm dome showing corner softness. The link also has a couple of frames from a 200mm dome with a 17mm lens showing that with the S&S lens an 8" dome is probably OK - depending on your standards. On the lens choice I would suggest the f4 lens - you will never need the extra stop underwater so save your $$ and put it towards a big dome! On Ikelite vs Nauticam or others - plenty of people are happy with ikelite housings - they are built to a price but they are cheaper for a reason.
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