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New a6xxx housing from Meikon

Discussion in 'Sony Snappers' started by CanadaDan, Oct 25, 2017.

  1. Barmaglot

    Barmaglot Manta Ray

    # of Dives: 100 - 199
    Location: Israel
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    Between the three you listed, the 6" will work the best, although 8" will give slightly better corners - just a bit. Standard port will produce significant distortion underwater at wide angles, and wet lenses won't work at all with 10-18mm - it's too wide. In fact, while I don't own one, I'm not sure 10-18mm will even fit in it - it's sized for the 16-50mm, and 10-18mm is slightly longer when zoomed out. I did some testing a while ago, comparing 4", 6" and 8" domes and the standard flat port with 7.5mm fisheye, 10-18mm and 16-50mm lenses at various focal lengths and apertures; you can see the results here.
     
    CanadaDan likes this.
  2. thebrain

    thebrain Nassau Grouper

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    @Barmaglot
    Thank you very much for the reply and samples.
    My assumption is correct then that the 6” dome + 10-18 is the best option optically for wide angle if I don’t want to deal with the size and buoyancy of the 8” dome.

    Am I also correct that image quality with the 10-18 and 6” dome would be generally better than the 16-50 plus a WA wet lens on the flat port ( if such a thing is even possible with the setup. )?
     
  3. Barmaglot

    Barmaglot Manta Ray

    # of Dives: 100 - 199
    Location: Israel
    692
    264
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    The standard flat port is not equipped to take wet lenses. The image quality with the short macro port + wet wide lens depends on the actual wet lens used, and is not directly comparable with 10-18mm + dome because wet wide lenses produce fisheye distortion while 10-18mm is a rectilinear lens. You will likely get a wider diagonal and sharper corners with a wet wide lens, but, again, at the cost of distortion.

    The 8" dome is not massively bigger than 6"; in fact, the actual diameter of the acrylic portion is approximately 180mm, although the housing adds about a centimeter to its margins. Here are the three domes and the standard port lined up for comparison:

    JAOusSM.jpg

    FWIW, since I did the tests I linked above, my 6" dome has been sitting on a shelf and I've been using the 8" for all my wide-angle dives. As far as buoyancy goes, I used car wheel weights attached to the back of the dome base to get it fairly close to neutral. They come in small increments, and the sticky pads that they mount on don't seem to be affected by salt water.
     
  4. Barmaglot

    Barmaglot Manta Ray

    # of Dives: 100 - 199
    Location: Israel
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    For the reference, this is what it looks like fully rigged and ready to dive (minus port cover):

    enDHXlC.jpg

    The shade petals rotate for easier handling on land; I turn them 90 degrees before submerging.
     
  5. mi000ke

    mi000ke Manta Ray

    # of Dives: 100 - 199
    Location: Massachusetts & Grand Cayman Island
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    I just did my first dive with a sony A6400, 16-50 kit lens and the 4" dome and it would not obtain focus (the dome is too close to the lens) except once at about 20 mm, out of 70 shots . Will be trying it again if I can figure out how to get a diopter to Grand Cayman, as no one here carries them. I emailed SeaFrogs and they replied that it was OK for them to claim the 4" dome would work with the kit lens as it might work for some people some of the time. It does not. (They did propose that the best solution was to sell me a 6" dome). So If you do use the 16-50 either get the 6" dome or a diopter (disclaimer: I have not tried either, so am only assuming that a diopter or larger dome will work.)
     
  6. CanadaDan

    CanadaDan DMC ScubaBoard Supporter

    # of Dives: 50 - 99
    Location: Winnipeg, MB Canada
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    IMG_1353.jpg DSC02483ps (Large).jpg DSC02276ps (Large).jpg DSC02350ps (Large).jpg DSC02474 (Large).JPG

    Just finished a few days diving in Tulum. This is the first time I've had the 'completed' rig in the water (matching Big Blue video lights & S&S strobes). Added a 1 pound lead to the bottom of the tray to drop the centre of gravity along with automotive wheel weights to the bottom of the dome and she has perfect neutral buoyancy in salt water and hangs vertical when I let go.

    30mm macro lens did well but I'm going to check out fitment of the 50mm macro for my next trip.

    Only time I had trouble with focus was in a stirred up haloclyne in Cenote Calavera.
     
    SuperSeaMonkey likes this.
  7. Nemrod

    Nemrod Solo Diver

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    CanadaDan, how did those generic eBay float arms do for you? I just bought a pair but am concerned they will likely fill with water with my luck. Reviews seem okay overall.

    Nice shots.

    James
     
  8. Barmaglot

    Barmaglot Manta Ray

    # of Dives: 100 - 199
    Location: Israel
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    I have four of those, used them on maybe 70-80 dives so far, no leaks or other issues.
     
    Nemrod likes this.
  9. CanadaDan

    CanadaDan DMC ScubaBoard Supporter

    # of Dives: 50 - 99
    Location: Winnipeg, MB Canada
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    Those (and the rest of the tray and arms) are the arms from Sea Frog/Meikon/Kitdive. They work well. The only fault I ever had was when I used them as the first arms off the tray and had my carry strap clipped too them. Stress was too much and broke the threaded insert in the carbon fibre. Even then they never leaked.

    Sea Frog replaced the arms for free despite my misuse.
     
  10. Nemrod

    Nemrod Solo Diver

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    Oh, okay, thanks. They sure look like these and I suspect they are:

    https://www.amazon.com/MINIFOCUS-Un...ater+camera+strobe+arms&qid=1580745879&sr=8-5

    Good to hear from two sources they have held up. I will purchase either the Inon or Nauticam float arms once I am more settled on my NA-6400 configurations. Hopefully these will work initially. I will use a carry handle rigged from the NA-6400 handles. Thanks for the tip to not support the rig from the arms.

    James
     
    CanadaDan likes this.

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