Shooting Technique, Workflow and Editing / Archived topic
Started by Pajjpen ·
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I've got a na-gh4 with 2 archon w42vr video lights, using either the 14-42 lens with macro port or the 7-14mm with a dome. I'm in the process of buying float arms such as the carbon fiber ones from nauticam, and I'm wondering if there's any formula or something I could use to see how much lift I need to make it somewhat neutral?
Cheers!
Hi Pajjpen
I've never actually tried what follows - I tend to use the wet-finger-in-the-air-that'll-do method - but:
Put your gear together. Tie it on to a set of hand scales and then lower the gear into the water - keeping the scales out of the water! The scales will tell you the buoyant weight of the gear. You then need to find arms/floats which will give buoyancy equal to the weight the scale read to create neutral buoyancy. Most float/arm manufacturers will tell you how much buoyancy their gadget will provide.
Bear in mind that there is a difference in buoyancy between salt water and fresh water.
The scales are like this:
Hope this helps!
Great help, didn't think about the hand scale thingy! Gotta get one and check it out, cheers
No worries!
Like I say, I have never tried it but I thought it was a cool idea!
I'm sure it will work, gonna have to tie my lights to the housing once I get them as I'm currently "arm-less" once the lights hit my mail I'll test it out and update!No worries!
Like I say, I have never tried it but I thought it was a cool idea!
Perfect time to be buying arms then. You can chose ones with the right buoyancy characteristics - or get non-buoyancy arms and add something like Stix foam. Lots of options 
I've tried both. I've got ULCS arms with Stix and then a pair of Inon Mega-Floats. Both good. I'd certainly recommend ULCS arms and clamps. I've had mine since around 2003 and they have been fantastic. I suspect they will outlive me.
FWIW, I've got the following setup, and it's almost perfectly neutrally buoyant with the dome port on...
NA-GH4
2x Sea&Sea DS4 strobes
2x i-Das arms (non-buoyancy - about 18cm long)
2x Nauticam Carbon Fiber Float Arm 200mm x 60mm / 8 In. x 2.4 In. (nau.72211)
Panasonic 7-14mm lens with dome port
It's so good that I've actually let the camera hang in midwater in front of me while I've mucked around stowing stage regs. (Admittedly, I was showing off - I don't routinely do that! /uploads/ogzalu.gif" /> )
I also shoot with the Olympus 60mm macro lens, and macro port. This is negatively buoyant, but not by much. You hardly notice when you're holding it.
Impressive!
Haha awesome pseudo. How negative is the strobes you have? The lights I ordered are about 320g negative a piece with the batteries
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