Bouyancy Arms
Posted: 22 July 2007 04:58 PM  [Ignore]
Flotsam (Treibgut)
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Does anyone use bouyancy arms with their strobes? 
My new camera is bit negative underwater, and alot heavy on the surface. 
Currently, I am using the Nikon D200, Aquatica housing, dual Ikelike DS-125 strobes, and original Ultralite arms.  Any suggestions on how to determine exactly how much I need for buoyancy from the arms. 
I am so busy with scuba and photography, I do not have extra time to add a new weightlighting program to strengthen my upper body to handle my underwater camera smile

Thanks!


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Posted: 23 July 2007 01:32 AM  [Ignore]  [ # 1]
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Napoleon Wrasse
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Auckland, New Zealand

Hi there Kathryn.

Nice rig!  I’m sure its heavy above water, but I suspect it would ‘float’ away if you didn’t keep a close eye on it!

Levity aside, I’m sure you are aware that ultralight supply bouyancy arms which replace the standard arm segments, however that would be a fairly committing move financially I suspect.

I have read (I think on one of the wetpixel forums; it was a while ago and I’m sorry but I don’t have the link) about a guy that did a DIY version of bouyancy arms by wrapping closed cell foam around the arms the same way that plumbers wrap foam around water pipes to insulate them.  This approach gave the ability to fine tune the added bouyancy by varying the length of the wrapping, i.e. how much of the arm was wrapped.

I imagine there was a fair bit of trial and error before the right amount of bouyancy was achieved, but apart from time, the cost was negligible.  If I remember correctly, putting bouyancy on the strobe arms also reduced the twisting/tilting moment he suffered due to the housing handles not being aligned with the centre of balance of the housing / rig.

HTH

Graham


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Graham
http://www.fishonfilm.co.nz

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Posted: 23 July 2007 09:15 AM  [Ignore]  [ # 2]
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Digideep team
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Germany / Sumatra, Indonesien

hi kathryn,

i am using the ULCS buoyancy arms (the normal ones) ... they are OK.
you can add them without problems ... they are not too buoyant for your rig. it will still be negative. but already much easier to handle. i am happy with mine. if not you can get the stix (is that how they’re called?) arms ... see the wetpixel threads ... you can order them ... arms ... and then you choose how much buoyancy you wanna have on the arms.

if you want to know how much you need you can just submerge your housing and fix it to a balance on the surface and measure how negative it is ... or if you dont have a hand balance, you can measure how much volume of water it displays and than calculate;)

but i think the normal buoyancy arms should be enough ...

greets, serge


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http://www.serge-mondial.com
Canon EOS 30D in INON X2 Housing

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Posted: 23 July 2007 04:14 PM  [Ignore]  [ # 3]
Fairy Baslet
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Kathryn,
I have the exact same setup plus the viewfinder w/ikelite arms w/ ikelite TTL adaptor and love it!!! I found I had the same issue and used swimming pool “noodles” (long floating tubes for kids to play with) cut them to fit the arm lengths and they work great. I do get a lot of questions about them, but they fit over the arm sections great. Only slighly negatively buoyant now. My problem is that the 1’ ball bulkheads that mount to the housing arms break loose (come unthreaded) on every dive and the strobes are flopping everywhere. They only thread into one of the holes provided on top of the handles. How are your arms mounted??
Thanks
TucsonDiver2
(previously Tucson Diver)


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Posted: 24 July 2007 03:31 AM  [Ignore]  [ # 4]
Flotsam (Treibgut)
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Ultralight sent me adapters for the Aquatica housing.  They came with 2 screws and the white thingy...I think it
keeps them from coming unscrewed.  Ultralight also sent adapters for the Ikelite strobes. 

I have only taken the strobes on one saltwater dive with no issues..


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Nikon Arm Adapter 503.jpg
Camera: NIKON D200
Lense: 75mm ISO: 200
F-Stop: f/5.0 Shutter: 1/125
Full Exif

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Posted: 29 November 2007 04:53 AM  [Ignore]  [ # 5]
Fairy Baslet
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I am experimenting with wrapping a foam yoga mat around the arms.  I haven’t tried it in anything but a bucket yet, but it appears it will be positive on the surface.  Question: I know the material with compress, bit will it compress to the point where it is essentially useless...?  Any advice comments or suggestions will be greatly appreciated.  Thanks.

John


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IMG_5975.JPG
IMG_5972.JPG
IMG_5971.JPG

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Posted: 27 December 2007 09:57 PM  [Ignore]  [ # 6]
Fairy Baslet
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BTW… all my concerns regarding the bouyancy of the flash were for naught.  Under field conditions the flash, and entire setup, was nearly neutral.  The 8” dome has a tendancy to turn the camera upward and puts a strain on the right for-arm, but this was rather minimal even after diving 5 days in a row.


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