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Camera Rig Negativity

Discussion in 'Sony Snappers' started by Nemrod, Jan 14, 2020.

  1. Nemrod

    Nemrod Solo Diver

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    I have never had a set up like my new Nautican NA6400 plus WWL-1 (and Inon UWL100+dome) and I knew in advance it would be heavy both in and out of the water. My previous UW camera rigs leaving out home made stuff going back to around 1974 has been a Nikonos and then a Nikonos III (strobes plus 28mm and 35mm lens) with tray, Ikelite "Bubble" and dome port with Nikon FM SLR and then an Ikelite with Olympus 5050, followed Ikelite with Canon A570 and finally a FIX housing with Canon S90. The later three used with a variety of wet lenses and strobes including the all glass Inon UWL100+dome. All three of these could get a little heavy and front heavy with the Inon glass lens but nothing I could not deal with.

    My couch potato rough calculations indicate the new rig could be as much as 34 ounces negative (not counting strobes and arms etc.) and with the WWL-1 float collar installed about 18 ounces negative. I can probably deal with the 18 ounces (float collar installed) but 34 ounces, probably not. The WWL-1 float collar is a nice chunk of foam and I will employ it but what if I do not want to install it? Or forget it?

    Basically, my question is, for UW photogs with negative rigs, what solutions are being employed to reduce UW weight? I see float arms, float collars (for lenses) and various pieces of foam tied around. I kind of want something that looks professional (even though I am not) and is easy to set up and transport. Any ideas appreciated. Thanks.

    James
     
  2. Barmaglot

    Barmaglot Manta Ray

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    Use a luggage scale to weigh your rig in water, then get the appropriate amount of float arms or stix floats. If you want to get fancy about it, Kraken/Weefine adjustable float arms are an option - these can be partially flooded to fine-tune the amount of buoyancy they give and get your rig fully neutral.
     
    Doppler likes this.
  3. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

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    Lots of threads in this here in SB and also on Wetpixel. Usual advice is to hang your rig from a luggage scale into a tub of water and determine its in-water weight, rather than try and calculate it. Then, add buoyancy so you end up slightly negative...a few ounces is enough, 18 is probably too many. Buoyancy can come from float arms (best, most expensive) or STIX floats (decent price, modular, take forever to dry!), or DIY from PVC tubes or syntactic foam. Avoid pool noodles or anything else that compresses with depth. Do some searching and you'll find the buoyancy of various float arms.
     
    rsingler likes this.
  4. jgttrey

    jgttrey ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Houston
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    Good advice above.

    FWIW, I have an A6500 in a Nauticam housing and use 2x of the Nauticam Carbon Fiber Float arms. Those are clamped to the housing with shorter conventional arms outboard of those for the strobes.

    I'd have to check on whether the Nauticam float arms are the 50x250mm version or the 70x250mm. In any event, they work well. My rig is very, very slightly negative with my Zen dome, a little more negative with the smaller 4" Nauticam dome but very manageable.

    The glass wet lenses are quite negative relative to a dome port, of course. I've found that the collars are not very effective for buoyancy changes. Perhaps useful for trim/balancing so you aren't so front heavy, but they aren't buoyant enough to make a meaningful difference on overall buoyancy.

    I'd weigh your rig and decide on appropriate arms based on what you need.
     
  5. Bigbella

    Bigbella Barracuda

    # of Dives: I'm a Fish!
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    I had a similar issue with a heavy Subal housing, along with two Inon strobes, mounted on Ultralight arms, some years back. Before, I thought about investing in anything else, such as "float" arms, I went to the local Loew"s and bought lengths of foam pipe insulation, and affixed then to the arms with cable ties, which were highly effective, and just under 10.00 . . .
     
  6. jgttrey

    jgttrey ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 200 - 499
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    That works fine for shallow dives, but that is pretty compressible stuff. The nice thing about the CF floats is that they work just as well at 200'+. I don't that foam would work so well at 7atm plus.

    You can get some burly closed cell foam that is more robust, but it usually comes in blocks and is a bit of a PITA to shape to the arms. I've used it for homemade float collars before thought.
     
  7. Nemrod

    Nemrod Solo Diver

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    Thanks, when you get an opportunity, see if you can remember the arm specifics. I have been looking this morning at the Nauticam CF arms in a 200X70 which are 370 grams positive each (26 ounces positive for both).

    Still, I expect the rig to be nose heavy. I should have gotten a weight the other day in the pool but I did not. Mostly because I did not bring strobes etc. I was just doing a pool test for the Inon UWL100+dome. Which is similar in weight to the Nauticam WWL-1.

    I currently use UCS 200mm arms with the option to add additional outboard arms at 100mm. I usually just use the single arms.

    James
     
  8. Bigbella

    Bigbella Barracuda

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    I have used it successfully to 60 meters, plus, with little appreciable change in buoyancy . . .

    The smooth material was slightly more effective -- longer lasting, anyway -- than the pitons variety . . .
     
  9. jgttrey

    jgttrey ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Houston
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    That surprises me, but I can't argue with success. Maybe I'll give that a try for some accessories. I assume this is the stuff with the smooth outside finish rather than the stuff that is more like a pool noodle?

    @Nemrod, I measured my Nauticam CF arms. They are 60x200mm. That particular size is no longer available, but it was an option at one time. Since mine are perfect with dome ports, my guess is that with your nearly identical rig but with wet lenses, the 70x200 might work well.
     
    Nemrod likes this.
  10. Nemrod

    Nemrod Solo Diver

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    Thanks all. I am not against home solutions like pool noodles as my bank account has been severely diminished, lol. In the short term I may need to just man up and carry the thing. I really like the pro look (not to mention functionality and durability) of Nauticam products so I will need to spring for their arms, I am thinking the 200X70 arms will be about right. Not sure what to do about fore and aft balance.

    I know it would add expense and complication (triggering for example) but if the housing (tray) arms could rotate fore and aft to change the felt CG or more correctly center of buoyancy of a rig while in the water it would be helpful to that end.

    I may try to duplicate the Nauticam WWL-1 float collar in CF. Probably balsa core it. Weird, but my old Ikelite Bubble housing, I had to add lead to sink it.

    James
     

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